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The 60th Yamada Conference on Research in High Magnetic Fields (RHMF2006) was held at Sendai Civic Auditorium, Miyagi Prefecture, Japan, from 16–19 August 2006, as the 8th RHMF. The first was held in Osaka (1982) followed by Leuven (1988), Amsterdam (1991), Nijmegen (1994), Sydney (1997), Porto (2000), and Toulouse (2003). RHMF2006, which was also a satellite conference of the 17th International Conference on Magnetism (Kyoto, 20–25 August 2006), covered a broad range of topics concerned with research in high magnetic fields: (1) magnetism, (2) strongly correlated electron systems, (3) superconductors, (4) metals and metallic nanostructures, (5) molecular systems, (6) semiconductors, (7) field effects on non-magnetic systems, (8) neutron and x-ray experiments in high magnetic fields, (9) magnet technology, (10) measurement techniques in high magnetic fields, and (11) high field facilities.

First of all we would like to express sincere thanks to the Yamada Science Foundation for their support and encouragement. We would like to thank all the members of the International Advisory Committee and the Program Committee for their collaboration. The conference was organized as usual with oral sessions having both invited and contributed talks and poster sessions. The technical program started on the morning of Thursday 17 August, with a tutorial lecture by Professor M von Ortenberg. The special posters were invited to introduce recent activities and up-to-date equipment of 17 high field facilities in the world. On the Friday evening, we had a banquet at Sendai City Museum for the history and culture of Sendai, with Emeritus Professor M Date (a Chairman for the first conference in Osaka) and many other guests. The conference was closed with a talk by Professor F Herlach on the afternoon of Saturday 19 August. We heard with great pleasure the announcement from Professor J Wosnitza that next RHMF will be held in Dresden in 2009.

This conference had 197 participants, 9 of which were women and 62 were from 17 countries other than Japan. Finally we would like to thank all the participants and authors for their contributions to the success of RHMF2006.

Mitsuhiro Motokawa Chairperson, RHMF2006

Ladies and Gentlemen

On behalf of Yamada Science Foundation, I would like to extend our hearty welcome to all of you who are participating in the 60th Yamada Conference and International Symposium on Research in High Magnetic Fields particularly to those who have come a long way to Japan from various places all over the world.

Yamada Science Foundation was founded in 1977 at Osaka, Japan. It develops its activities by giving support to the outstanding research projects in the basic natural sciences, especially in the interdisciplinary domains that bridge between well established research fields such as physics, chemistry, and biology. The Foundation also provides travel funds for scientists to visit or to go out of Japan in order to carry out international collaborative projects. It also holds conferences and workshops. Among these activities, one of the most important is the organization of Yamada Conferences, which are usually held two or three times a year on various topics which seem to be pioneering current research activities in natural sciences. Upon organizing Yamada Conferences, The Board of Directors of The Foundation put emphasis on the three symbolic English letter `I's. The first I stands for International, the second I means Interdisciplinary, and the third, perhaps the most important I symbolizes Innovative. As for this conference, I think it is in some sense interdisciplinary, because it deals with on one hand, the smallest scale of matter, the elementary particles while, on the other hand deals with the largest scale of matter, the universe, which are linked together. I also think many innovative ideas are presented in this conference. In this context, I believe this Conference is well suited to the scope of our Foundation. Another important aspect of holding Yamada Conference is to provide the forum of `Friendship' among the participants. We encourage all of you, particularly young scientists, to get acquainted with each other not only through hot discussions in the conference rooms but also through pleasant chatting on the lobby floor or even at the banquet table, which may give rise to other important international collaborative projects in the near future.

Finally, we would like to express our sincere thanks to Professor Mitsuhiro Motokawa and the members of the organizing committee who have made every effort to bring in such a successful performance of the Conference. I hope all of you would enjoy the Conference and relax sometime staying in this interesting scientific city of Sendai.

Thank you.

Hidetoshi Fukuyama On behalf of Director General, Professor Yasusada Yamada Yamada Science Foundation

Yamada Science Foundation was established in February 1977 in Osaka through the generosity of Mr Kiro Yamada. Mr Yamada was President of Rohto Pharmaceutical Company Limited, a well-known manufacturer of medicines in Japan. He recognized that creative, unconstrained, basic research is indispensable for the future welfare and prosperity of mankind and he has been deeply concerned with its promotion. Therefore, funds for this Foundation were donated from his private holdings.

The principal activity of the Yamada Science Foundation is to offer financial assistance to creative research in the basic natural sciences, particularly in interdisciplinary domains that bridge established fields. Projects which promote international cooperation are also favored. By assisting in the exchange of visiting scientists and encouraging international meetings, this Foundation intends to greatly further the progress of science in the global environment. In this context, Yamada Science Foundation sponsors international Yamada Conferences once or twice a year in Japan. Subjects to be selected by the Foundation should be timely and stimulating. These conferences are expected to be of the highest international standard so as to significantly foster advances in their respective fields.

Executive Members of FoundationOfficers:Board of Directors Leo ESAKI Kenichi HONDA Hiroo INOKUCHI Masao ITO Junjiro KANAMORI Takako KAWABA (Standing Director) Tadamitsu KISHIMOTO Yoshitaka NAGAI Tetsuo SHIBA Yasusada YAMADA (Director General) Auditors: Hisaya NARA Kumao TOYOSHIMA Advisors: Kiyoshi SEGAMI Syuzo SEKI

The attached PDF file contains various photographs taken at the conference.

We report on measurements of magnetic and thermodynamic properties on two different Cu²⁺-containing S = 1/2 dimer systems. One is the recently synthesized metal-organic system C₃₆H₄₈Cu₂F₆N₈O₁₂S₂ (TK91). At temperatures T < 0.2K and fields around 6T, strong enough to close the spin gap to the excited triplet state, indications for a field-induced phase transition are observed making this system a potential candidate to study the Bose-Einstein condensation of magnons. The second system is the natural mineral Cu₃(CO₃)₂(OH)₂(azurite) which was identified as a distorted diamond chain–a realization of a 1D quantum frustrated system. We find a huge acoustic anomaly around 31T accompanying a magnetic soft mode.

BaCuSi₂O₆ is a model spin dimer system in which a BEC QCP is realised. Universal BEC power law scaling is experimentally observed, with 3d critical behaviour above 0.5 K, but a crossover to 2d BEC critical scaling down to 30 mK. Here we briefly review and expand on the results presented in the recent Nature paper [8].

Studies of novel quantum effects in quantum spin systems by high field ESR will be reviewed. High field ESR measurements of the Haldane system Y₂BaNiO₅ doped with nonmagnetic ion Mg²⁺have been performed. We have succeeded in resolving the ESR of finite Haldane chains using the high resolution feature of our high field ESR, and the direct information about the spin correlation in the Haldane chain at low temperature is obtained for the first time.

We discuss high-field magnetic properties of the quasi two dimensional frustrated dimer spin system SrCu₂(BO₃)₂, which is a realization of the Shastry-Sutherland spin model and shows magnetization plateaus at 1/8, 1/4 and 1/3 of the saturated magnetization. Based on the results of ¹¹B NMR experiments, we discuss (1) the spin superstructure in the plateau phases, (2) the effects of anisotropic interactions such as the Dzyaloshinski-Moriya interaction, and (3) nature of the phases above the 1/8 plateau.

Magnetization plateaux, visible as anomalies in magnetic susceptibility at low temperatures, are one of the hallmarks of frustrated magnetism. An extremely robust halfmagnetization plateau is observed in the spinel oxides CdCr₂O₄ and HgCr₂O₄, where it is accompanied by a substantial lattice distortion. We give an overview of the present state experiment for CdCr₂O₄and HgCr₂O₄, and show how such a half-magnetization plateau arises quite naturally in a simple model of these systems, once coupling to the lattice is taken into account.

The magnetic-excitation spectrum of copper pyrimidine dinitrate, a material containing S = 1/2 antiferromagnetic chains with alternating g-tensor and the Dzyaloshinskii-Moriya interaction, and exhibiting a field-induced spin gap, is probed using tunable-frequency electron spin resonance spectroscopy in magnetic fields up to 25 T. The data are interpreted in frame of the sine-Gordon quantum-field theoretical concept proposed recently by Oshikawa and Affleck. The field-induced gap is measured directly; signatures of soliton and three breather branches are identified.

Strongly frustrated antiferromagnets such as the magnetic molecule {Mo₇₂Fe₃₀}, the kagome, or the pyrochlore lattice exhibit a variety of fascinating properties like low-lying singlets, magnetization plateaus as well as magnetization jumps. During recent years exact many-body eigenstates could be constructed for several of these spin systems. These states become ground states in high magnetic fields, and they also lead to exotic behavior. A key concept to an understanding of these properties is provided by independent localized magnons. The energy eigenvalue of these n-magnon states scales linearly with the number n of independent magnons and thus with the total magnetic quantum number M = Ns − n. In an applied field this results in a giant magnetization jump which constitutes a new macroscopic quantum effect. It will be demonstrated that this behavior is accompanied by a massive degeneracy, an extensive (T = 0)-entropy, and thus a large magnetocaloric effect at the saturation field. The connection to flat band ferromagnetism will be outlined.

We have conducted low- and high-field magnetization measurements and neutron diffraction experiments on Nd_xEr_1−xMn₆Sn₆ alloys (0 ⩽ x ⩽ 0.5) with hexagonal MgFe₆Ge₆ type structure. The alloy with x = 0.1 shows a complex helical antiferromagnetism with the magnetic moments rotating in the c plane below the Curie temperature T_C = 340 K, and a ferrimagnetism below the temperature T_t = 100 K. In the ferrimagnetic state, the magnetic moments μ_Mn and μ_Nd are parallel to each other, and antiparallel to μ_Er. The alloy with x = 0.4 shows also a similar ferrimagnetic structure below the Curie temperature T_C = 360 K. It is likely that the each magnetic moments are keep a constant values of μ_Mn = 2.3 μ_B/Mn atom, μ_Nd = 3 μ_B/Nd atom and μ_Er = 9 μ_B/Nd atom at 10 K in the whole composition (0 < x ⩽ 0.5). The ferrimagnetic arrangements for the alloys with 0.2 ⩽ x ⩽ 0.5 are not almost disturbed by magnetic field up to 26 T at 4.2 K.

We studied the magnetic properties of ZnCr₂O₄ under an ultra-high magnetic field by using the Faraday rotation method. We used a single turn coil system to generate a pulsed high field up to 180 T and used a He-Ne laser as a light source. We chose a 45 degree angle between the polarizer and the analyzer and measured a transient Faraday rotation signal by using a photo-diode and a transient recorder. The sample temperature was kept below Neel temperature during the experiment. We observed a discernible discontinuity in a Faraday rotation signal at 120 T. This discontinuity is considered to represent the first-order phase transition which is observed also in CdCr₂O₄which has the same geometrical structure as ZnCr₂O₄.

Measurements of magnetization were carried out for single crystals of TbCu₄Ag and GdCu₄Ag under magnetic field up to 18 T at temperatures of 1.7, 3.0 and 4.2 K. At 4.2 K, two stepped field-induced transitions were observed in magnetizing process along all the [111], [110] and [100] directions. At 1.7 K four stepped transitions were observed only along the [100] direction. For GdCu₄Ag unusual increase of magnetization was observed in high field magnetization process.

The magnetization M of single crystalline TmB₄ has been investigated in high magnetic fields up to 54 T and shows considerably anisotropic behavior. In the ordered antiferromagnetic state, the M for B ∥ [001] reaches the saturation magnetization M_s at about 4 T accompanying with plateaux at 1/8 M_s and 1/2 M_s. On the other hand, for B ∥ [100] and [110], the 1/2 M_s state and the saturation of Mwere observed at much higher field above 30 T. The results are discussed in relation to the effects of magnetic frustration and the crystalline electric field.

Measurements of high-field magnetization up to 18 T, magnetic susceptibility and specific heat have been performed on a tetragonal NdRh₂Ge₂ single crystal and polycrystalline sample. From the temperature dependences of magnetic susceptibilities, this compound shows an antiferromagnetic behaviour with Neel temperature of 50 K. Another magnetic transition is observed at 37 K. At low temperatures, a multi-step metamagnetic behaviour is observed along the easy c-axis and a strong magnetic anisotropy is seen. The saturation magnetic moment is estimated to be 2.76 μ_B/f.u.. There are five magnetic phases below the induced ferromagnetic phase in the H-Tmagnetic phase diagram. To discuss the magnetic behaviours, the CEF analysis has been made.

The intermetallic compound Pr_1-x-yLa_xPb_yTe shows a wide spectrum of physical phenomena. Depending on the metallurgical composition as function of x and y, the compound changes its behavior from van Vleck paramagnetism and hyperfine-enhanced nuclear-magnetic order to super- or semiconductivity. In addition, there are remarkable interplay effects between these ground states. In consequence, Pr_1-x-yLa_xPb_yTe may serve as an interesting material for nuclear-spin quantum-computing experiments. In this contribution, we focus on measurements of the magnetic properties performed in high magnetic fields. We present first data of the magnetization of Pr_1-yPb_yTe taken in pulsed magnetic fields up to 47 T for the compositions y = 0, 50, and 90 %.

NaCu₂O₂ is regarded as an S = 1/2 zigzag chain with competing nearest neighbor and next nearest neighbor exchange interactions. The spin structure of NaCu₂O₂ below a Néel temperature T_N = 13 K was reported to be helical with a propagation vector q = (0.5, 0.227, 0). To obtain further information on the ordered state of NaCu₂O₂, we performed multi-frequency electron spin resonance (ESR) and high field magnetization measurements on single crystal samples of NaCu₂O₂. We observed a large and some small ESR signals and a monotonical increase of magnetization with a change of the slope around 20 T. One of the ESR resonance modes from the large signal is roughly reproduced by one of the helical resonance modes calculated on the assumption of a conical spin structure.

In single crystals of A-site disordered perovskite manganites R_1−xAE_xMnO₃ (R = Sm, Gd, Eu, AE = Ba, Sr, x = 0.5, 0.45), we have observed the spin-glass behaviour. Applying pulsed high magnetic fields, a metamagnetic phase transition was observed in some samples, whereas in other samples, the magnetisation was just a smoothly varying function of magnetic field up to the saturation. The difference between the two types of behaviour seems to arise from the difference in the average ionic radius of the A-site ions and the disorder in the A-site layers. In the metamagnetic transition, magnetisation hysteresis was found to be smaller as the field sweep rate is faster, which is contrary to the ordinary spin relaxation phenomena.

We suggest using insulating Van Vleck paramagnet PrF₃ as a solid substrate for the dynamic polarization of ³He nuclei at high magnetic fields. The exploring of solid effect for this purpose assumes the knowledge of the optimal conditions for transfer of polarization from the Pr³⁺ electron shell in PrF₃ to ¹⁴¹Pr nuclear spins as well as the existence of effective channel for magnetization transfer from ¹⁴¹Pr nuclear spins to nuclear spins of liquid ³He (so-called magnetic coupling phenomenon). To study solid effect in PrF₃ the magnetic field dependencies of the Stark energy levels of ³H₄ ground state multiple were calculated for high magnetic fields up to 40 T using the set of crystal-field parameters obtained early from magnetization measurements and exchange charges model. Also the results of searching for a direct magnetic coupling between nuclei of the liquid ³He and ¹⁴¹Pr nuclei in the system "PrF₃ powder – liquid ³He" by pulse NMR method are represented. Also the surface effects in the PrF₃ crystal were studied by SQUID and optical microscopy measurements. Other aspects of the nuclear polarization transfer are discussed.

High-field magnetization up to 18 T and magnetic susceptibility measurements have been performed on a TbCu₂Si₂ single crystal. The magnetic susceptibility shows an antiferromagnetic behaviour with two anomalies at T_t = 9.1 K and T_N = 11.9 K. The easy magnetization direction is the [110] direction in the basal plane. The magnetization along the easy direction shows a multi-step metamagnetic process in low fields. It is almost saturated above 8 T and reaches 8.7 μ_Bat 16 T. A strong magnetic anisotropy between the [110] and [100] directions is observed at high fields. A one-step metamagnetic transition appears around 13 T at 4.2 K in the hard [001] magnetization process. This transition survives at 13 K even above T_N. These magnetic behaviours are discussed from an analysis of crystalline electric field.

We report 1H NMR results for (CH₃)₂NH₂CuCl₃measured at very low temperature down to 0.1 K using a dilution refrigerator. Field induced magnetic ordered state is revealed by the NMR measurements and a magnetic phase diagram for the system is proposed.

An organic triradical, BIPNNBNO [ = 3,5-bis(N-tert-butylaminoxyl)-4'-(1-oxyl-3-oxide-4,4,5,5-tetramethylimidazolin-2-yl)biphenyl] includes an antiferromagnetic spin pair of S = 1 and S = 1/2 within a molecule. In the crystals, ferrimagnetic chains are formed, accompanied by the antiferromagnetic interactions between the nearest and the next nearest neighbouring chains. These interactions induce frustrated spin structure in two-dimension. X-band and submillimeter EPR measurements of BIPNNBNO single crystals were performed. The change of the g-factor and linewidth was observed corresponding to the susceptibility and magnetization behaviour.

We report on pulsed field magnetization and ESR measurements of the family of copper(II)-substituted polyoxotungstates [Cu₃(H₂O)₃(α-XW₉O₃₃)₂]¹²⁻. (X = As, Sb) where the three Cu²⁺(S = 1/2) ions form an antiferromagnetically-coupled triangle. The distinct features are the observation of half step magnetization and hysteresis loops as well as asymmetric/symmetric magnetization between a positive and negative field, depending on the diamagnetic heteroatom X. This is attributed to the interplay between an adiabatic magnetization and Dzyaloshinskii-Moriya interactions. Moreover, the more symmetric magnetization curve of X = Sb is discussed in terms of dynamical mixing of a S = 1/2 state via a phonon mode.

We have performed high field magnetization measurements on the quasi onedimensional (1D) antiferromagnet BaCo₂V₂O₈, which shows a curious field-induced orderdisorder transition, in pulsed magnetic fields up to 55 T. The observed magnetization curves up to the saturation field show non-linear increases, suggesting a strong quantum fluctuation. We analyze the magnetization curves in terms of the S = 1/2 1D XXZ model.

A quantum spin magnet NH₄CuCl₃ is a three dimensional dimer system, which shows a two-stepped magnetization plateaus at M = 1/4 and 3/4. In order to investigate the spatial configuration of field-induced triplons under high-field, Cu-NMR study has been performed in the field region between the first and the second plateau. It has been found that the same numbers of the differently-oriented two dimers in a unit cell remain unoccupied by triplons. This gives a strong restriction to the model to describe the plateaus in this system.

ESR measurements have been performed on poly crystalline sample of an S = 1/2 Heisenberg antiferromagnetic ladder-like system (C₅H₉NH₃)₂CuBr₄. We estimated the g-value as g = 2.20 from analysis of a broad absorption line at high temperatures. Multiple ESR absorption lines were observed below 10 K. The ESR modes show non-linear frequency dependence of the resonance field at 4 K, and the temperature dependence of the line width with a thermal activation type formula. The ESR modes observed are well explained by the theoretical model of the breather excitation.

Magnetically ordered states in the chiral spin system CuB₂O₄have been studied by ESR measurements. Two resonance absorptions are observed in the helimagnetic state, which imply that the two inequivalent copper sites are in the helimagnetically ordered state and the paramagnetic state with a development of short range order. The frequency-independent dip with hysteresis on the spectrum is also observed in the helimagnetic state. The behavior of the dip can be interpreted by the change of the dielectric properties rather than the magnetic resonance.

Ge_1−xCr_x films grown by MBE show quite large magneto-transport effects in the temperature range up to the room temperature. Especially, Hall resistance in DC- fields up to 10 Tesla and magneto-resistances in pulsed fields up to 60 Tesla show significant nonlinear field dependence. The magnetic field effects on the transport properties are usually quite small in conducting materials and phonon plays main role above liq. N₂ temperature. ESR measurements suggest that antiferromagnetism up to T_Naround 70 K exists and the critical spin fluctuation might affects to the nonlinear field dependence in magneto-transport phenomena in high temperatures.

Magnetic twist driven giant magneto-resistance in Fe/Tb multilayer system is studied under high pressure up to 3.2 GPa. The R(H) - H (R(H): magnetoresistance) curve is described in [Fe(12 nm)/Tb(15 nm)]₂₅ multilayer as a function of magnetic field at various pressures. It is found that R(H) does not saturate but keep an enhancement by applied magnetic field up to 9 T at 4.2 K. It is consistent with the fact that the magnetization does not have saturated but enhance, that is, the direction of Tb magnetic moment by inner of Tb layer turn to applied magnetic field. The MR ratio, which is defined as MR = ΔR/R(0), where ΔR = R(8.5 T) - R(0), is obtained to be 9.5 % at 4.2 K at ambient pressure, and decreases as increasing pressure. It is suggested that the pressure effect on MR is mainly due to a change in ΔRby applying pressure, that is, spin-dependent part of the electrical resistivity is suppressed by applying pressure.

The magnetic properties of ErMn₆Ge₆have been investigated on single crystals that have been prepared in an In flux. The compound orders antiferromagnetically at 475 K and undergoes a second magnetic-ordering transition at 120 K. The evolution of the magnetization in the ordered state as a function of temperature and the magnetization processes have been investigated in fields up to 14 T. At 4.2 K, the magnetization process has been studied in pulsed fields up to around 50 T.

We report on the strongly anisotropic thermal expansion (TE) and magnetostriction (MS) of a GdRu₂Si₂single crystal measured along the principal crystallographic directions (the a- and c-axis, respectively) down to 2K and magnetic fields up to 14T. The MS (positive along the c-axis and negative in the perpendicular direction) reflects the three magnetic field induced transitions, for the field applied along the c-axis with a significant hysteresis (0.05T) for the transitions in low fields. Independently on the magnetic field direction there is a remanent MS along the a-axis after removing the field, suggesting irreversible evolution of magnetic structures.

Temperature dependence of DC and AC magnetic susceptibility and high field magnetization are studied for a single crystal of ErZn₂. The results indicate ErZn₂to be an antiferromagnet and show an anisotropic and complicated field induced magnetic transitions.

The angle dependences of magnetization and hyperfine–enhanced ¹⁶⁹Tm NMR in concentrated Van Vleck paramagnet LiTmF₄ have been studied at temperature 4.2 K. NMR has been observed at frequencies 372.7 MHz at 15 kOe and 653 MHz at 25 kOe. The magnetization of LiTmF₄single crystal was measured at magnetic fields up to 55 kOe. The NMR spectra as well as magnetization were substantially anisotropic. Experimental dependences are in good agreement with calculated ones obtained with taking into account the influence of magnetostriction on crystall field.

GdCo_9−xSi_4+x (x = −0.2 to x = 0.2) and TbCo₉Si₄ exhibit the tetragonal LaFe₉Si₄ structure (space group I4/mcm). Magnetically these samples are ferrimagnetic with ordering temperatures close to 50K. The ferrimagnetic magnetization is found to decrease with decreasing Si content, thus, revealing an increasing cobalt sublattice magnetisation. The antiparallel coupling of the Gd- and Co-sublattice magnetisations breaks up at lower critical fields H_l well above 20 T. From the lower critical field H_l as well as from the slope ΔM/ΔH for fields above H_lthe inter-sublattice molecular coefficient can be determined which is approximately constant within this solid solution.

We report on anisotropy of magnetic, transport and elastic properties in the PrCo₂Ge₂ single crystal measured down to 2K and magnetic fields up to 14T. The zero field data reflects two anomalies, T_N = 28 K and order-to-order transition at T_R = 8 K. Within application of magnetic field along the c-axis these transitions join each other in field about 9 T. The properties measured at 2K with respect to the magnetic field applied along the c-axis reflect two field-induced transitions (2 T and 10 T). The high field transition is accompanied by significant drop in magnetoresistance (5%) and magnetostriction (7 × 10⁻³).

The magnetization of a Dy₂Fe₁₄Si₃ single crystal was measured at 4.2 K in pulsed fields up to 52 T along the principal axes. The compound is a ferrimagnet with T_C = 500 K, has a spontaneous magnetic moment of 9 μ_B(at 4.2 K) and exhibits a very large magnetic anisotropy, ⟨100⟩ being the easy axis. In fields applied along the ⟨100⟩ and ⟨120⟩ axes, field-induced phase transitions are observed at 33 T and at 39 T, respectively. The c-axis magnetization curve crosses the easy-axis curve at 23 T. At higher fields, for all directions, the magnetization continues to increase due to further bending of the sublattice moments.

The temperature and field dependence of the magnetization were measured on a single crystal of the antiferromagnet UIrGe in pulsed fields up to 51 T, and the specific heat in steady fields up to 18 T. At low temperatures, metamagnetic transitions are observed at critical fields B_c of 21 T and 14 T, applied along the b- and the c-axis, respectively. At 2 K, the magnetization jumps at B_c are 0.36 μ_B/U along the b-axis and 0.28 μ_B/U along the c-axis. The a-axis is the hardest magnetization direction with a weak linear magnetic response. Both along the b- and the c-axis, B_cdecreases with increasing temperature. Consistent with the magnetization, the sharp anomalies observed in the specific-heat obey the same dependence.

Zero-field-cooled (ZFC) and field-cooled (FC) magnetizations have been measured for β-FeSi₂ single crystals from 4 to 300 K up to 60 kOe using a SQUID magnetometer. The ZFC and FC magnetizations at low field below 500 Oe show the characteristic temperature dependence due to superparamagnetism (SP). The blocking temperature T_bwas well explained by the theory for the SP. We have found an anomalous peak (AP) at around 55 K, which is caused by some kind of magnetic transition. The AP is enhanced appreciably with increasing magnetic field but whose peak temperature is field-independent. Moreover, its magnetization develops temporally with the delay time 16.5 h.

We report magnetism of Cu₂CdB₂O₆ and Cu₃(P₂O₆OH)₂ that show a magnetization plateau. In Cu₂CdB₂O₆, a 1/2 magnetization plateau in magnetic fields above 23 T and antiferromagnetic (AF) long-range order (AFLRO) in low fields were observed. There are two kinds of Cu sites [Cu(1) and Cu(2)], which are located adjacent to each other. Spins on the Cu(1) and Cu(2) sites are in a nearly spin-singlet state and form AFLRO, respectively, although interactions between the Cu(1) and Cu(2) spins cannot be ignored. Cu₂CdB₂O₆ is the first material that shows such coexistence in an atomic scale. In Cu₃(P₂O₆OH)₂, a spin-1/2 threefold-period chain with J₁-J₂-J₂ interactions exists, where J₁ and J₂ denote two AF exchange interaction parameters. A 1/3 magnetization plateau was observed above 12 T. Cu₃(P₂O₆OH)₂ is the first model compound of AF threefold-period chains showing a magnetization plateau.

The magnetization process of the S = 1 and S = 2 spin alternating ferrimagnetic chain with the single-ion anisotropies is investigated by the numerical exact diagonalization and the density matrix renormalization group method. It is found that the mechanism of the 2/3 magnetization plateau formation due to quantum effects depends on the anisotropy constants. The obtained phase diagram of the 2/3 plateau is revealed to include three different phases.

Field-induced quantum ordered phases in the anisotropic S = 1 Haldane system are studied, using an effective Lagrangian formalism. We predict that, when the applied field is inclined from the principal axes of the spin anisotropy, successive phase transitions occur from the Haldane phase to a field-induced ordered phase followed by another spin-reorientation transition from the one to other field-induced ordered phase at high fields. Depending on the anisotropy constants, the spin-reorientation transition is of the first order or of the second order via another type of the ordered phase. Relevant implications of these transitions are further discussed in connection with the novel ordered phase recently observed in the Haldane system, NDMAP, at high fields.

Using mainly numerical methods, we investigate the ground-state magnetization curve of a mixed spin chain with uniaxial single-ion anisotropies, where S = 1 and S = 2 spins are alternating and coupled antiferromagnetically. Special attention is paid to the magnetization plateau, the 1/3-plateau, which appears at one third of the saturation magnetization in the magnetization curve. It is found that there appear three kinds of 1/3-plateaux, one of which has a quantum nature, while the remaining two have a classical (Ising) nature.

We investigate dynamical properties of the half-magnetization plateau in S = 1 bond-alternating spin chains. Dynamical structure factors calculated by the exact diagonalization method are compared with the dispersion curves of low-lying excitations obtained by a cluster expansion technique. We find that in the half-magnetization plateau the quintet excitation forms the lowest-lying excitation. The field dependence of the critical exponents of the spin correlation functions are further investigated. On the basis of the results, characteristics of the half-magnetization plateau are discussed.

Magnetic susceptibility and specific heat measurements in magnetic fields were performed on an S = 1/2 one-dimensional antiferromagnet KCuGaF₆. Exchange interaction was evaluated as J/k_B≃ 100 K. However, no magnetic ordering was observed down to 0.46 K. It was found that an applied magnetic field induces a staggered magnetic susceptibility obeying the Curie law and an excitation gap, both of which should be attributed to the antisymmetric interaction of the Dzyaloshinsky-Moriya type and/or the staggered g-tensor. With increasing magnetic field H, the gap increases almost in proportion to H^2/3.

Cu Pyrimidine Cu(C₄N₂H₄)(NO₃)₂(H₂O)₂ and Cu Benzoate Cu(C₆H₅COO)₂·3H₂O are molecule-based S = 1/2 antiferromagnetic Heisenberg chain systems. Because of a staggering of the g tensor and the Dzyaloshinskii-Moriya interaction, the magnetic prinicpal axis system a''bc'' is distinct from the crystallographic unit cell. Along a'' a behavior corresponding to the uniform S = 1/2 antiferromagnetic Heisenberg chain occurs, while along c'' the effect of staggering of the g tensor and Dzyaloshinskii–Moriya interaction are most prominent. Here, we discuss the field and temperature dependent magnetization along a'' and c'' of these systems, in particular with respect to the relevance of the inhomogeneity parameter k controlling the ratio between longitudinal and transverse magnetization components.

Magnetic torque τ and magnetostriction ΔL/L measurements were carried out in the spin gap system (CH₃)₂CHNH₃CuCl₃. The magnetic torque shows a cusp-like anomaly at the magnetic field H_a1with increasing the magnetic field, and the magnetostriction shows a kink at almost the same magnetic field. These results suggest that anomalous change in the magnetic torque is associated with the lattice distortion, and it is expected that the field-induced magnetic phase transition is not simple Bose-Einstein condensation in this system.

We have performed high field magnetization and multi-frequency electron spin resonance (ESR) measurements on single crystal and powder samples of Na₂Fe₂(C₂O₄)₃(H₂O)₂, abbreviated as SIO. The Fe²⁺ ions in SIO are bridged by oxalate groups to make two-leg ladders. The temperature dependence of magnetic susceptibilities parallel and perpendicular to the leg direction show very different and anisotropic behavior. Experimental results of the isomorphous compound Na₂Co₂(C₂O₄)₃(H₂O)₂ (SCO) are well explained by isolated magnetic dimers with an Ising-type anisotropy. Therefore, we analyze the frequency dependence of the ESR resonance fields by the same model with a fictitious spin 1 as in SCO. The agreement between experiment and calculation is satisfactorily good. Magnetic susceptibility and magnetization curves calculated with the same parameters obtained in the ESR analyses, however, do not agree well with the experimental ones. This indicates the presence of the exchange interaction between the dimers, namely the interaction along the leg.

The magnetic properties of the ferromagnetic ring-shaped single-molecule magnet (n-BuNH₃)₁₂[(CuCl)₆ (AsW₉O₃₃)₂] · 6H₂O, known as Cu₆, have been studied by electron spin resonance (ESR). The ESR spectra show several sharp absorptions, which originates from the multiplet splitting of the high spin ground state S = 3. Meanwhile, the frequency-field plot of the observed ESR shows a gap at zero-field suggesting the existence of an anisotropic exchange interaction in the system. Moreover, forbidden ESR transitions of ΔS_z = ±2 have been also observed where the origin comes from the mixing of the spin state by virtue of the transverse field component of the anisotropy.

Cu-NMR study has been performed on the disordered spin-gap system Tl_1−xK_xCuCl₃ In the high-field H > H_C = Δ/μ_B, where Δ is the spin-gap, the hyperfine field becomes extremely inhomogeneous at low temperatures due to the field-induced magnetic order, indicating that the ordered spin state must be different from the pure TlCuCl₃. In the low field H < H_C, a saturating behavior in the longitudinal nuclear spin relaxation rate T⁻¹₁was observed at low temperatures, indicating existence of the magnetic ground state proposed to be Bose-glass phase by Fisher.

(CH₃)₂CHNH₃CuCl₃ is described as the spin ladder system, which is composed of a strong ferromagnetic rung and a weak antiferromagnetic leg. Since the ferromagnetic dimer behaves like S = 1 spin, this system can be treated as the S = 1 quasi-one-dimensional antiferromagnet spin chain (so-called Haldane chain). Cl-NMR study under high-field up to 17.5T has been carried out in order to investigate the field-induced magnetic order in this system. In the lower field region below 10T, the signals from Cl-sites were observed as sharp NMR lines. These paramagnetic lines showed the split above H^red_N ≃ 12T (T = 1.85K), demonstrating the existence of the staggered field due to the field-induced magnetic order. Around H_N, the resonance lines disappeared due to the critical slowing down when the applied magnetic field was perpendicular to the ladder, whereas they did not when the field was nearly parallel to the ladder. These results indicate that the spin dynamics around the field-induced magnetic order is anisotropic in this system.

We discuss our numerical results on the properties of the S = 1/2 frustrated J₁-J₂Heisenberg model on a square lattice as a function of temperature and frustration angle ϕ = tan⁻¹(J₂/J₁) in an applied magnetic field. We cover the full phase diagram of the model in the range π ⩽ ϕ ⩽ π. The discussion includes the parameter dependence of the saturation field itself, and addresses the instabilities associated with it. We also discuss the magnetocaloric effect of the model and show how it can be used to uniquely determine the effective interaction constants of the compounds which were investigated experimentally.

We report on a detailed investigation of the magnetism in A-type CeCu₂Si₂ by neutron scattering, thermodynamic and transport measurements. The linewidths of the magnetic peaks broaden well below the Néel temperature T_N ≈ 800mK pointing to a finite domain size/correlation length. In contrast, within the resolution of the experiments the magnetic order is static. Complementary measurements of the electrical resistivity observed a superconducting transition at T< 450mK well below T_N. However, no anomaly has been detected in heat capacity measurements. All results indicate that A-type single crystals exhibit parasitic superconductivity limiting the size of the antiferromagnetically ordered regions. The observed behavior can be understood by the slight off-stoichiometry of A-type CeCu₂Si₂.

TmAgGe is an antiferromagnet based on the ZrNiAl structure. At low temperatures the spins are confined to distorted kagome-like planes, wherein the magnetisation is strongly anisotropic. A previous study has shown that a series of stepped magnetic transitions are apparent in low, in-plane magnetic fields and can be explained using a three-fold Ising-like model. Here we present high-magnetic-field magnetisation experiments showing that further stepped transitions are observed when the field is directed out of the kagome planes. Angledependent measurements in fields of up to 55 T show that there are at least two distinct and separate energy scales present in this system; the weak exchange interactions and the strong crystalline electric field interactions. Simulations of the magnetisation using a three-dimensional, free-energy minimisation technique allow us to suggest the nature and hierarchy of the forces acting on the Tm³⁺moments.

We measured the high-field magnetization up to 55 T and constructed a magnetic phase diagram for a transuranium antiferromagnet NpRhGa₅ with the tetragonal structure. The magnetization at 4.2 K for an easy-axis H//[100] indicates a metamagnetic transition with a sharp step at H_c = 26 T and saturates above H_s = 38 T, reaching 0.43 μ_B/Np at H_s. On the other hand, the magnetization saturates at H_s = 28 T for a hard-axis H//[001], reaching 0.44 μ_B/Np at H_s. The magnetization indicated that the magnetic moment reduces from 0.96 μ_B/Np at zero field to 0.44 μ_B/Np at the saturation field as a function of magnetic field. These experimental results in NpRhGa₅ are compared with the simple magnetism in UPtGa₅with the similar antiferromagnetic structure.

In-plane (ab) and out-of-plane (c-axis) magnetoresistivity display different symmetry crossovers and/or transitions in 14 T magnetic field applied parallel to the CuO₂planes. The in-plane magnetoresistivity crosses over from four-fold symmetry below 6 K to two-fold symmetry at higher temperatures, which becomes dominant at temperatures higher than 40 K. The out-of-plane magnetoresistivity changes at 17 K from four fold symmetry to ordinary sin²θ at higher temperatures. The behaviour of the c-axis magnetoresistivity can be ascribed to the antiferromagnetic ordering of the Pr spins whereas the symmetry change of the in-plane magnetoresistivity at 6 K might be attributed to commensurate to incommensurate crossovers of the spin subsystems. The antiferromagnetic order of the Cu(2) sublattice seems to have only a week effect on the magnetoresistivity.

Transport properties of crystalline (La,Bi)_1−xSr_xMnO₃ and Bi_1/2Ca_1/2MnO₃ were studied in the spin-polarized states induced by chemical substitution or applied magnetic fields. Substitution of lanthanum for bismuth changes the ground state from antiferromagnetic insulator to ferromagnetic metal. The electronic states in the boundary region remain unclear due to the non-uniform distribution of lanthanum ions. Application of high magnetic fields to Bi_1−x(Sr,Ca)_xMnO₃causes negative magnetoresistance effects in the charge-ordered state. All the samples studied do not show metallic conduction even in the highly spin-polarized state. The nature of the spin-polarized insulating state is discussed in relation to the ferromagnetic insulators in lightly-doped manganites.

Ce₃Pd₂₀Si₆ forms in a cubic crystal structure with the cerium atoms located on two different sites, both of cubic point symmetry, resulting in two interleaved cubic cerium sublattices. We present here the results of detailed low-temperature specific heat and electrical resistivity measurements taken in magnetic fields up to 14 T, with the purpose of shedding light on the complex low-temperature behaviour that was alluded to in previous literature reports on this compound. Our specific heat data show two phase transitions, at T_L(B = 0) = 0.31 K and at T_U(B = 0) = 0.5 K respectively, probably of magnetic origin, and with distinctly different response to applied magnetic fields. T_L is shifted towards lower temperatures and becomes indiscernable in fields above 1 T. T_U on the other hand is shifted upward and disappears in fields above 8 T. The electrical resistivity data follow a Δρ ∝ T^5/3 power-law behaviour below T_U for a limited range in field, suggestive of spin fluctuations near a three-dimensional ferromagnetic quantum phase transition.

A setup for ultrasonic measurement in pulsed magnetic fields was established in this work. We first introduce the basic ideas of this measurement. Using this setup we measured the longitudinal elastic constant C₁₁ and the corresponding ultrasound attenuation β₁₁ up to 28 T for the filled skutterudite compound SmRu₄P₁₂. At 14 K, C₁₁ shows steep increase while β₁₁a large peak at around 8 T, indicating the magnetic ordering of this compound. Anomalies were also observed at 4.2 K, however, it is not clear if these correspond to phase transitions.

We performed a detailed electrical transport study at very high magnetic fields and low temperatures in high quality single crystals of Sr₄Ru₃O₁₀. When the field is applied along the inter-plane direction Shubnikov-de Hass oscillations are observed showing that a metamagnetic transition leads to a quite non-trivial evolution of the geometry of the Fermi surface. It can be ascribed either that localized and itinerant bands coexist in this system, the former leading to the ferromagnetic response and the latter to itinerant metamagnetic behavior, or that itinerant metamagnetism emerges from a Stoner-like ferromagnetic ground state.

Ultrasonic measurements were made on a single crystal of the filled skutterudite compound SmOs₄Sb₁₂. A remarkable elastic softening toward low temperature was observed in the elastic constants C₁₁, (C₁₁-C₁₂)/2 and C₄₄ as a function of temperature, followed by a sharp drop which is associated with the onset of ferromagnetic ordering, and then display a monotonic increase below T_c. The present results indicate that the crystalline electric field (CRF) effect would not support straightforward the observed elastic softening toward low temperature. We suggest that this fact is originated from valence instability of the Sm ion at low temperature in SmOs₄Sb₁₂. The 4f electronic ground state of the Sm ion and its elastic property are discussed.

UGe₂ has orthorhombic C_mmm crystalline symmmetry and shows ferromagnetic Heavy-Fermion (HF) Superconductor, which provides superconductivity under pressure in the range from 1.0 GPa to 1.5 GPa. Magnetic field dependence of magnetization shows strong magnetic anisotropy. When a magnetic field is applied parallel to easy axis (a-axis), magnetization presents ferromagnetic behavior. At 4.2 K, which is much lower than the Curie temperature T_c = 54 K. Spontaneous magnetization is 1.4 μ_B/U, and the magnetization gradually increase with increasing field. On the contrary, when a field is applied parallel to hard axis (b-axis or c-axis), magnetization increases linearly with increasing magnetic field. As for H//b-axis, magnetization is 0.23 μ _B/U even at 27 T. Magnetocrystalline anisotropy constant is obtained as 230 [T μ_B] = 3.4[kJ/kg] at 4.2 K. This value is comparable with rare-earth magnet Nd₂Fe₁₇, which is typical strongly correlated ferromagnet.

Magnetic-field effects on the charge-spin stripe order in La-214 high-T_c cuprates have been investigated from measurements of the in-plane electrical-resistivity, ρ_ab. In La_2−xBa_xCuO₄ with x = 0.10 and La_2−xSr_xCuO₄ with x = 0.115 where the incommensurate charge peaks are weak and unobservable in zero field in elastic neutron-scattering measurements, respectively, the normal-state value of ρ_ab at low temperatures markedly increases with increasing field up to 27 T. For La_2−xBa_xCuO₄ with x = 0.11 and Zn-substituted La_2−xSr_xCu_1−yZn_yO₄ with x = 0.115 and y = 0.02 where the charge stripe order is fairly stabilized in zero field, on the other hand, the increase in ñab with increasing field is negligibly small. In conclusion, when the charge-spin stripe order is not fully stable in zero field, magnetic field operates to stabilize the charge-spin stripe order. The value of ρ_ab increases with increasing field depending on the stability of the charge stripe order.

We present de Haas–van Alphen (dHvA) measurements of the nonmagnetic rareearth borocarbide superconductor LuNi₂B₂C which have been performed by using a torque cantilever for temperatures down to 0.45K and in magnetic fields up to 32.5T. We mapped the dHvA oscillations of a high-quality single crystal by rotating between all three principal crystallographic axes [100], [001], and [110]. This set of data gives a complete overview of the electronic band structure of LuNi₂B₂C. A comparison with band-structure calculations allowed us to assign the dHvA frequencies to individual bands. Overall positions and band dispersions resemble those observed in the isostructural compound YNi₂B₂C, which is another nonmagnetic member in the family of the borocarbide superconductors.

We have measured resistivity ρ(H, T) and magnetization M(H) up to 15T in heavy ion irradiated untwinned YBa₂Cu₃Oy single crystals in order to study effects of columnar disorder on the vortex phase diagram. With increasing irradiation dose B, the first-order vortex lattice melting transition T_m(H) is suppressed near the upper and lower critical points. For B = 0.5 T, the first-order transition exists in the very narrow field region between 4.5 T and 10 T without any characteristic features such as the field-driven order-disorder transition H*(T) line in the vortex solid phase. The first-order transition completely disappears and the transition becomes the second-order Bose glass transition when B_ϕ ⩾ 1.0 T.

We studied effects of the c-axis correlated disorder on the vortex liquid state in REBa₂Cu₃O₇ (RE123; RE = rare earth including Y) superconducting bulk samples. The dip structure for B//c-axis in the angular dependent resistivity appears for all samples used in this study. This means the reduction of the dissipation in the vortex liquid state by the c-axis correlated pinning. We analyzed the reduction of the dissipation by the c-axis correlated pinning by using the resistivity difference between on and off the dip, Δρ^max_n . We found that Δρ^max_n shows the different field dependence for a part of the NEG123 bulk samples in comparison with those of the Y123 bulk samples. The different field dependence of Δρ^max_nis originated from the different type of the c-axis correlated defects such as twin boundary and probably nanolamella.

The buckling of CuO2 plane in single crystals of La_2−xSr_xCuO₄ (LSCO) [x = 0.08] and La_2−x−yBaySr_xCuO₄ (LBSCO) [x = 0.06 , y = 0.065] was directly observed by high-field Cu-NMR spectra. The split pattern in the NMR spectra of LSCO [x = 0.08] shows that the local structure is Low Temperature Orthorhombic (LTO) like at low temperature, consistent with the results reported by diffraction experiments. In LBCO [x = 0.08], the local structure is Low Temperature Tetragonal (LTT) like, while the averaged structure is reported to be LTO. In LBSCO, the local structure is found to be either LTT-like or Low Temperature Less- Orthorhombic (LTLO) between 35 and 70 K, while the averaged structure is reported to be LTO. With decreasing temperature, the resonance peak disappeared below 35 K, indicating the appearance of Charge Density Wave (CDW) or Spin Density Wave (SDW).

We report on the superconductivity of n-type InN. There is an optimum carrier density for the occurrence of the superconductivity. The lowest carrier density is limited by the Mott transition of n_c = 2 × 10¹⁷ cm⁻³ and the highest density is limited by the superconductivity to metal transition of n_i ∼ 7 × 10²⁰cm⁻³. We propose a mechanism where the occurrence of the superconductivity is related to the presence of In-In chains of finite lengths in the ab plane. The In-In chains, which originate from the inversion domains of InN grown on sapphire (0001) and elongate along [110], are coupled to form micro Josephson-junctions.

The study of granular effects in resistive superconducting transitions of ceramic ruthenocuprate RuSr₂(Gd_1.5Ce_0.5)Cu₂O_10−δprepared by a solid-state reaction method is presented for samples as prepared (ASP) and annealed (12 hours at 845°C) in pure oxygen at 62 atm. The resistive transitions for different measuring currents and applied magnetic fields (up to 8 T) bear evidence of granularity effects determined by inhomogeneous structure of the samples. This is dictated by the polycrystalline structure (with a grain size of a few μm) and oxygen deficiency in grain boundary regions. The resistive curves show clearly the intragranular and intergranular superconducting transitions, the intergranular superconductivity being determined by the Josephson coupling between the grains. This has allowed determination of intragranular (T_c0) and intergranular (T_cg) critical temperatures, which are ≈ 34 K and ≈ 9.4 K in ASP sample, and ≈ 37.3 K and ≈ 32.8 K in the 62-atm sample in zero field. The magnetic-field dependences of these characteristic temperatures were studied and discussed. In general, the granularity effects are most pronounced in the ASP sample where great sensitivity to applied current and low magnetic field is found. These effects become, however, much weaker after oxygen annealing.

The microstructure and superconducting properties of Bi-2223/Ag tapes fabricated in high magnetic fields were investigated. The results show that the partialmelting temperature has influence on the formation of Bi-2223 phase and the J_c. The optimum partial-melting temperature is 855°C. The magnetic field during sintering at 830°C has no influence on the formation of Bi-2223 phase and the J_c. However, the magnetic field during partial-melting process has obvious influence on the formation of Bi-2223 phase and the J_c. The tape partially melted with 10 T magnetic field shows stronger c-axis alignment of Bi-2223 phase and higher J_cvalue than that partially melted without magnetic field.

We have measured the out-of-plane resistivity ρ_c of Pb-doped Bi2201 in strong magnetic fields up to 40 T. ρ_c measurements in 40 T have confirmed the existence of two kinds of pseudogap, namely the field-insensitive pseudogap PG1 and the sensitive PG2 which have been suggested from previous ρ_c measurements in 15 T. In the overdoped sample with the superconducting transition temperature T_c = 4 K, we have succeeded in the complete suppression of PG2. The temperature dependence of ρ_cin 40 T has indicated that the nonmetallic ρ_c(T) appears without PG2 on account of the existence of PG1 and/or the chargeconfinement in the ab-plane.

We determine the temperature dependence of the upper critical field H_c2 in KOs₂O₆ from resistivity and magnetic measurements in high magnetic fields up to 50 T. By both techniques we find linear temperature dependence all the way below Tc and uncommonly high H_c2 (T → 0 K) ∼ 33 T. We show that this unusual H_c2 can be understood as a consequence of paramagnetic limit H_Premarkably enhanced by the broken spatial inversion symmetry proposed recently, ensuring that the pair-breaking here is executed by orbital degrees, associated with the smaller closed Fermi surfaces.

Condon domains form when the de Haas-van Alphen (dHvA) amplitude becomes large compared to the dHvA period, i.e. μ₀∂M/∂B > 1, where M is the magnetization and B the induction. This equation defines the boundary between the homogeneous magnetization and the Condon domain state. The phase diagram in the (B, T) plane can be predicted using the Lifshitz-Kosevich formula. We present the Condon domain phase diagram for a silver single crystal measured in magnetic fields up to 28 T and temperatures Tdown to 1.3 K. A standard ac method with a pickup coil system is used at low frequency for the measurements of the de Haasvan Alphen (dHvA) e..ect. The transition point from the state of homogeneous magnetization to the inhomogeneous Condon domain state is found as the point where a small irreversibility in the dHvA magnetization arises, as manifested by an extremely nonlinear response in the pickup voltage showing threshold character. The experimental results are in good agreement with theoretical predictions based on the Lifshitz-Kosevich formula.

Transport measurements of low-dimensional conducting crystals, graphite and NbSe₃, have been carried out under destructive pulsed ultra-high magnetic fields up to 120T. RF reflection technique has been employed to pick up the signal from huge induction noise. Sample crystals have been fabricated into thin wire-shape to avoid self-heating due to induced eddy current. We report recent experimental results on two subjects; (1) enhancement of electron correlation in the magnetic quantum limit, and (2) characteristic energy spectra of Bloch electron systems under ultra-high magnetic fields.

We have investigated effect of magnetic field on γ(austenite)↔α(ferrite) equilibrium temperature T₀ in Fe-xCo alloys with x = 0, 10, 20, 30 mol%. The α-phase at T₀ is paramagnetism for x = 0 and 10, while it is ferromagnetism for x = 20 and 30. We have found that T₀ increases almost proportional to magnetic field for the Fe-20Co and Fe-30Co alloys, while it does almost proportional to square of magnetic field for pure Fe and the Fe-10Co alloy. The increase in T₀by applying magnetic field of 10 T is about 7 K for pure Fe, 18 K for the Fe- 10Co alloy, 24 K for the Fe-20Co alloy and 20 K for the Fe-30Co alloy. The results are discussed on the basis of the Clausius-Clapeyron equation.

Effect of magnetic field on disorder-order transformation in CoPt has been investigated. Single crystals of disordered (A1-type) CoPt were heat-treated at 773 K for 0.5 h under various magnetic fields up to 10 T applied along the [001]_A1direction, and then annealed at 1023 K for 3 h under zero magnetic field. When the magnetic field in the first stage of ordering heat-treatment is larger than 0.5 T, a single variant state of L1₀-type ordered phase with the easy axis (c-axis) being parallel to the applied magnetic field direction is obtained.

The condition for the rearrangement of martensite variant (RMV) by magnetic field has been studied quantitatively in a wide temperature range for two types of alloys: a Ni₂MnGa with 10M martensite and a Ni_2.02Mn_1.09Ga_0.89 with 14M martensite. The RMV by magnetic field occurs at any temperature for the 10M martenste but only in a limited temperature range for the 14M martensite. The magnetic field at which the RMV starts to occur, H_s, increases with decreasing temperature for both alloys. The condition for the RMV by magnetic field is explained by two shear stresses: the magnetic shear stress acting across twinning plane t_mag (which is evaluated as the difference in magnetic energy between variants divided by twinning shear) and the shear stress required for twinning plane movement t_req. That is, the RMV by magnetic field starts to occur when t_mag exceeds t_req regardless of temperature and structure of martensite.

The interlayer magnetoresistance ρ_zz of the organic metal κ-(BEDTTTF)₂Cu(NCS)₂ has been studied in fields B of up to 45 T and at temperatures T from 0.5 K to 50 K. The peak in ρ_zz seen in exactly in-plane fields, a definitive signature of interlayer coherence, remains to Ts exceeding the Anderson criterion for incoherent transport by a factor ∼ 25. Angle-dependent magnetoresistance oscillations (AMROs) due to Fermi-surface orbits are suppressed by rising T, with a T²dependence suggesting electron-electron scattering.

The effect of the disorder induced by the deuterated BEDT-TTF (d-BEDTTTF) molecule substitution on the superconductivity has been investigated in the quasi two dimensional organic superconductor κ-[(h-BEDT-TTF)_1−x(d-BEDT-TTF)_x]₂Cu(NCS)₂. The scattering time τ obtained by the de Haas-van Alphen effect changes in the form of 1/τ ∝ x(1 − x), which is known as Nordheim relation. Although the scattering time takes minimum around x = 0.5, the superconducting transition temperature T_c increases linearly with x. The relation between the scattering time and T_cis not simply explained by the nonmagnetic impurity effect in the unconventional superconductivity expected in this organic superconductor.

Magneto-transport properties of the newly prepared layer-structured organic conductor β''-(BEDT-TTF)₂CsCd(SCN)₄ are investigated. Temperature dependence of the interlayer resistance without magnetic fields shows a hump-like anomaly between 32 K and 5 K at ambient pressure. Measurements of the Shubnikov-de Haas oscillations indicate that the electronic structure at low temperature is different from that calculated from the crystal structure at room temperature. Under magnetic fields parallel to the layer, magnetic field dependence of the interlayer resistance also shows a large dip-like anomaly below 32 K, where the hump-like anomaly starts to appear. We suggest that the hump-like anomaly of β''-(BEDTTTF) ₂CsCd(SCN)₄is a density wave transition accompanied by nesting of its one dimensional Fermi surfaces, and that the dip-like anomaly in the magneto-resistance is ascribed to magnetic field dependence of the interlayer hopping of electrons.

We performed high field magnetization measurements up to 55 T for newly synthesized antiferromagnetic charge-transfer salts, (Benzo-TTFVS)₂FeBr₄ with T_N = 5.8 K and (Benzo-TTFVO)₂FeBr₄ with T_N = 9.3 K. A spin-flop behavior at 1.8 T and a saturation at 14.8 T were observed in the magnetization curve at 0.5 K for the (Benzo-TTFVS)₂FeBr₄ salt. For the (Benzo-TTFVO)₂FeBr₄salt a spin-flop at 6.9 T and a saturation at 36.2 T were observed. We estimate the exchange interaction between d spins and the magnetic anisotropy for both salts from the magnetization data.

We have measured the magnetothermal e..ect of κ-(BEDT-TTF)₂Cu(NCS)₂in a wide field range, and clearly observed the temperature spikes due to the flux jumps and the quasi-periodic temperature oscillations before the flux jumps in the two dimensional (2D) vortex lattice phase. The temperature dependence of the magnetothermal e..ect suggests that the melting transition from the 2D vortex lattice to the vortex liquid phase in low temperature is driven by quantum fluctuations rather than thermal one.

Quasi-one-dimensional (Q1D) organic conductors with simple open Fermi surfaces have provided novel angular dependent magnetoresistance oscillation (AMRO) phenomena for the last two decades. Both semiclassical and quantum mechanical theories well explain these phenomena, but detailed study of the field dependence probably gives a crucial test. Recently it was proposed that a kind of AMRO that is known as "Lee-Naughton oscillations (LNO)" observed for (TMTSF)₂ClO₄ is a result of dimensional crossover of electronic system from oneto two-dimension on changing the field orientation. We have studied the field dependence of the magnetoresistance of Q1D superconductors (TMTSF)₂ClO₄ and (DMET)₂I₃by using a 46-T pulsed magnetic field system and found the B^1/2-behavior at minima of LNO.

To understand the interplay between transport and magnetic properties, quasi-two-dimensional (Q2D) organic conductor τ-(EDO-S,S-DMEDTTTF)₂(AuCl₂)_1+y was studied by measurements of electric resistivity ( ρ_a, ρ_c), magnetoresistance (MR), susceptibility (χ) and specific heat (C) in the temperature region between 1 K and 300 K. In spite of the fact that the drastic changes were observed in ρ_a, ρ_c, MR and χ at T_C = 20 K, no anomaly was seen in C. The concentration of spins estimated from M-H curve is about 360 ppm, which is difficult to detect anomaly in C. These data suggest that the number of spins is very small in the ground state like spin-glass system.

The periodical oscillation of the Hall resistance as a function of the magnetic field (B) has been observed in the field-induced spin density wave (FISDW) state of (TMTSF)₂ClO₄in strong magnetic field [Uji et al. Phys. Rev. Lett. 94, 077206 (2005)]. The mechanism of this interesting phenomenon has not been explained. It is known that the periodic potential due to the ordering of the anion plays important role in the FISDWand the Hall conductivity. Although some properties such as the suppression of the FISDW state with even index are explained in the perturbative treatment of the periodic potential, the non-perturbative calculation is indispensable to this system because the periodic potential is thought to be not small. We calculate the susceptibility in the system to obtain the wave vector of the FISDW at strong fields. We also discuss the Hall resistance in the strong periodic potential case.

High frequency Electron Spin Resonance (ESR) up to ν = 1 THz and magnetization M(B) of a tetranuclear-Ni(II) single molecular complex of type [L₂Ni₄(N₃)(O₂CAda)₄](ClO₄) featuring an unprecedented central μ₄ - 1,1,3,3 azide have been studied in magnetic fields up to B = 55T. Bridging ligands provide intramolecular exchange paths of different strength between the four Ni ions each having a spin S_Ni = 1. T- and ν-dependent ESR measurements enable to accurately determine the energy spectrum of the spin states of the cluster as a function of B. A predominantly antiferromagnetic character of exchange renders the ground state nonmagnetic, S = 0, with a number of excited magnetic multiplet states, S = 1,. . . ,4. Remarkably, ESR gives evidence for the spin-level crossing in a field of ∼ 25T which turns the ground state of the cluster to a strongly magnetic one. This observation is confirmed by the static M(B) data.

Lebed resonance phenomenon which manifests sharp resistance minima at angles where the magnetic field imposes electrons a periodic motion on the Fermi surface, is readily observed in most of Bechgaard salts such as (TMTSF)₂ClO₄, (TMTSF)₂PF₆, (TMTSF)₂ReO₄. On the other hand, another type of oscillatory behavior, observed when the magnetic field rotates from the most conducting direction towards the least conducting direction, in the acplane, is found to vary much from one compound to another, having been clearly observed only in (TMTSF)₂ClO₄. We have performed a systematic study of both the bc- and ac-rotation measurements and report that the ac-plane resonances are also omnipresent and universal in all the three compounds. Difference among compounds, notably the strength of the coherence peak may be used to account for the evolution of coherence from one compound to another.

Magneto-optical measurements have been performed in organic conductors β''-(BEDT-TTF)₂CsCd(SCN)₄ and λ-(BETS)₂FeCl₄. Although the zero magnetic field ground state of β''-(BEDT-TTF)₂CsCd(SCN)₄is considered as the density wave state, periodic orbit resonances (POR's) attributed to quasi-one-dimensional (Q1D) and quasi-two-dimensional (Q2D) Fermi surfaces (FS's) have been observed above 6 T. The existence of these FS's are predicted by the band calculation based on room temperature lattice parameters. This result may suggest the destruction of the density wave state at 6 T, and the primal metallic state revives in the high field phase above 6 T. In the case of λ-(BETS)₂FeCl₄, large changes of the transmission intensity of electromagnetic waves around 10 T, which correspond to the insulator-metal transition, have been observed. However, no POR-like resonance has been observed. This may be due to the restriction of the observed frequency-field region.

New transition metal polyborate, CoB₁₂O₁₄(OH)₁₀ is synthesized by using boric acid as a flux. This material has isomorphic structure with MB₁₂O₁₄(OH)₁₀ (M = Mg or Ni), consisting of two-dimensional borate layers and quasi-square lattice of Co²⁺. The Co²⁺ ions locate in the plane of the two-dimensional layer, bridged through B_nO_n+1 chains in the plane and connected with the three-membered ring borate groups out of the plane. The dc magnetic susceptibility and magnetization measurements show that the material undergo an antiferromagnetic phase transition at T_N = 5 K. At T < T_N, a metamagnetic phase transition is observed at H_c = 2 T, associated by a spin-flop. The structural and magnetic properties of the transition metal polyborate represent an example of interesting magnetic interaction in diluent magnetic systems.

We report the magnetoresistance (MR) in 2D-organic conductor, β''(EDOTTFVO)₂FeCl₄. We found an anomaly at 8T in MR, which is field-angle-independent. We speculate that this behavior is associated with from antiferromagnetic to paramagnetic transition, occurring at the same magnitude of magnetic field irrespective of field direction. To realize this situation, comparable magnitude of J_πd and J_dis required, which is rather rare the case. The isotropic nature in the magnetic transition is remarkable in the anisotropic organic conductors.

A review of experiments on semiconductors in high magnetic fields is presented with special emphasis on transient megagauss fields generated by the singleturn coil and explosive flux-compression. Both, techniques of field generation and the special consequences of transient magnetic fields on the sample system will be discussed thoroughly. In detail several magneto-transmission experiments using 10.6 ìm wavelength radiation on bulk and nanostructured semiconductors will be presented in addition to special features of magnetization behavior.

High-field magnetotransport experiments provide an excellent tool to investigate the plateau-insulator phase transition in the integral quantum Hall effect. Here we review recent low-temperature high-field magnetotransport studies carried out on several InGaAs/InP heterostructures and an InGaAs/GaAs quantum well. We find that the longitudinal resistivity ρ_xx near the critical filling factor ν_c ≈ 0.5 follows the universal scaling law ρ_xx(ν, T) ∝ exp(-Δν/(T/T₀)^κ), where Δν = ν-ν_c. The critical exponent κ equals 0.56 ± 0.02, which indicates that the plateau-insulator transition falls in a non-Fermi liquid universality class.

We have measured the current distribution in GaAs/AlGaAs two-dimensional electron system (2DES) at quantum Hall effect (QHE) regime to investigate the mechanism of QHE breakdown. A Hall-bar device on the scanning stage is locally illuminated by an infrared laser light guided by polarization maintaining optical fiber at QHE condition. We have tried to map the QHE breakdown critical current with local photo-excitation. The mapping of breakdown critical current shows the current concentration at the center region of 2DES channel in the sample where the critical current shows sub-linear dependence on the channel width. We have also tried to measure the Hall potential imaging in the electric current flowing 2DES by means of Pockels effect in GaAs/AlGaAs sample. The experimental techniques of the optical fiber based current distribution imaging in the high magnetic field up to 9 T have been reported in detail.

Magnetoluminescence properties have been studied for 2 dimensional electron systems in a CdMnTe/CdMgTe single quantum well for dilute Mn concentration at high steady magnetic fields up to 35T. Singlet and triplet charged excitons are observed with varying the applied magnetic field, and a splitting of a luminescence peak based on the crossing of Zeeman levels have been found out around B = 12T. It is also found that anomalous photoluminescence peaks appear under the high magnetic field above B = 25T.

We present study of edge channels in high magnetic field by direct contrast interference measurement. We model our measures and we estimate geometrical characteristic for edge states. We find relevant parameter, even in plateaus regime, for the existence or not of the dialogue between opposite edge states which allows interference effect.

We have investigated the effect of accumulation of photo-created electrons in ZnSe/BeTe type-II quantum well (QW) structures by means of a pump-and-probe method in high magnetic field up to 7 T. A cw-diode laser was used as a pumping light source. With increasing pumping intensity neutral exciton (X) absorption are weakened and a distinct peak structure due to negatively charged exciton (X⁻) was observed at a 6 meV lower energy side of the X in ZnSe QW layers. The magnetic field dependence of circular polarization of X⁻ contains information about the density of twodimensional electron gas (2DEG). We found that high-density 2DEG (∼1×10¹¹cm⁻²) is optically injected by successfully using type-II quantum structures without n-doped layers.

Cooperative spontaneous recombination (superfluorescence) of electron-hole plasmas in semiconductors has been a challenge to observe due to ultrafast decoherence. We argue that superfluorescence can be achieved in quantum-confined semiconductor systems and present experimental evidence for superfluorescence from high-density photoexcited electronhole plasmas in magnetized quantum wells. At a critical magnetic field strength and excitation fluence, we observe a clear transition in the band-edge photoluminescence from omnidirectional output to a randomly directed but highly collimated beam. Changes in the linewidth, carrier density, and magnetic field scaling of the emission spectra correlate precisely with the onset of random directionality and are consistent with cooperative recombination.

This paper reports effects of magnetic-treatments on an interaction between dislocations and oxygen impurity in Si. Though oxygen impurity in Si has a strong effect of immobilizing dislocations due to preferential segregation and formation of precipitates along dislocations at elevated temperatures, the capability of immobilization of the oxide precipitates against dislocations decreases under an application of magnetic field higher than 5 T and loses almost completely at 10T. These results suggest a spin-dependent solid-state reaction in oxygen impurity-dislocation interaction in Si.

Magnetization measurements in pulsed magnetic fields up to 47 T have been performed on the magnetic (T_M,Ru ≈ 133 K) superconductor (T_S ≈ 46 K) RuSr₂GdCu₂O₈ in an attempt to determine the Ru valency in this compound. The Ru ions are most probably in a mixed valence state, but the ratio of Ru⁵⁺(S=3/2)/Ru⁴⁺(S = 1) ≈ 60%/40% suggested by NMR investigations is justified only if one considers the theoretical values of 3 μ_B/Ru⁵⁺ and 2 μ_B/Ru⁴⁺. Mixed valency could lead to a competition between ferromagnetic double exchange, evolving Ru⁴⁺ and Ru⁵⁺ ions, and antiferromagnetic superexchange, evolving Ru⁵⁺ ions, leading to magnetic phase separation. We conclude that the magnetic and superconducting properties of the rutheno-cuprates critically depend on the Ru⁵⁺/Ru⁴⁺ ratio which can be affected by the preparation conditions.

We have discussed the localization mechanism of hole-induced magnetic solitons and large magnetoresistance effects in diluted magnetic semiconductors, by using the effective Lagrangian and the supersymmetric sigma formula.

We report on a novel class of RF spintronics devices directed towards making nanoscale microwave sources. Microwave emission is produced by a process of spin resonance that occurs in hybrid semiconductor-ferromagnetic nanostructures when a two-dimensional electron gas is subjected to both a magnetic field gradient and a constant magnetic field applied at right angles of each other. Current injection activates electron spin oscillations in the magnetic field gradient, whilst conversely, driving the spin dynamics with a microwave field modifies the channelling resistance perpendicular to the magnetic field gradient. We have irradiated GaAs/AlGaAs/Dy nanowires and observed resistance peaks induced by the microwave field. We have analyzed their dependence in the 50-110GHz and the 6T-15T range to extract relevant spin parameters. The absorption of microwave by spin oscillators is compared to the ferromagnetic resonance of Dysprosium.

Magnetotransport and magnetic properties have been measured for β-FeSi₂ single crystals from 4.2 to 300 K using a pulsed magnet, a superconducting magnet, and a SQUID magnetometer. Nonlinear Hall effect followed by a normal Hall effect was observed, involving a hysteresis effect at low temperature. The signs of normal Hall coefficients changed from positive to negative ones at around 180 K. The magnetization curves above 180 K are well explained by considering the superparamagnetism. Below 150 K we found that the aggregates of Fe atoms exhibit an inter-aggregate ferromagnetic interaction. At low temperature we also found that the cohesive forces obtained from the ρ_H-B curves are larger than those from the M-Bcurves. This discrepancy was discussed qualitatively by a proposed model.

We have studied the optical properties of the modulation n-doped ZnSe/BeTe/ZnSe type-II quantum wells. The reflection spectra have shown typical negatively charged exciton features only in a doped sample. The electron density as well as the mass was determined in high magnetic field (up to 160 T) cyclotron-resonance measurements. Photoluminescence (PL) measurements were performed in pulsed high magnetic fields (up to 42 T) with a Faraday configuration. We found oscillations in both the PL intensity and the peak energy in the doped sample. These oscillations were originated from optical de Haas oscillations. It was found that the observed indirect PL transition occurs via the charged excitons in a type-II quantum configuration.

A levitating apple in a hybrid magnet implies the presence of microgravity conditions under gradient magnetic fields. However, several unique behaviors were found, the orientation of levitating rice grains, the alignment of levitating bismuth particles, and the thermal convection in water under the levitation conditions. These are unlikely under the microgravity conditions in the space and are characteristic of the magnetic levitation. On the basis of the understanding of such behaviors, the magnetic levitation was applied to containerless materials processing, and such an attempt resulted in the development of a magnetic levitation furnace.

Recent experiments in the Co-B eutectic alloy have evidenced the anisotropic growth of Co precipitates at high temperature in the solid state when an external magnetic field up to 16 Tesla is applied. Two mechanisms are considered in this study. Firstly, the magnetic forces around the poles of a ferromagnetic Co particle can locally trap the diffusing Co ions in the matrix. An analytical approach demonstrates that, although weak, this mechanism is comparable to the curvature driving force in the Ostwald ripening. Secondly, the external magnetic field can affect the motion of the diffusing charged ions. Assuming a magnetically induced anisotropy of diffusion, Monte Carlo simulations show that the precipitates first elongate in a direction perpendicular to the fast diffusion axis and then recover a spherical shape for long annealing times.

We have studied the dynamical orientation of single-walled carbon nanotubes (SWNT) dissolved in D_2Oinduced by pulsed magnetic fields. A wave-form of the field was varied from micro-to mili-sec in time, and the field strength was varied from several Tesla up to 100 T. Optical transmission through the liquid sample was detected in a pulsed magnet at room temperature. The linear polarization degree of the optical transmission was used as a measure for the average alignment of the SWNTs in the liquid. The application of a 40 T pulse field aligned the tubes by 12 degrees on average. A harmonic oscillator model with simple geostatics was used for a simulation. Our model well explains all the investigated cases in which a magnetic-field-dependent magnetic moment of the system is taken into account. Our experimental results agreed qualitatively with those of Ajiki and Ando. The term induced by the flux change (dB/dt) became important in low magnetic fields and during short pulses, which require a dynamical part of the magnetic susceptibility.

Containerless crystallization of benzophenone and containerless melting of a cycloolefin polymer were performed under magnetic levitation conditions. It was found that the growth mechanism changes from dendritic growth to facet growth with decreasing the supercooling degree in the crystallization of benzophenone. In the case of containerless melting and solidification of a cycloolefin polymer, spherical samples were obtained by a homogeneous heating in an electric furnace with a heatproof bore scope.

Magnetic field effect on the growth of cobalt silicate tubes in aqueous solution of sodium silicate is studied. Cobalt silicate tubes grown from CoCl₂ powders in 10wt.% sodium silicate solution under a horizontal magnetic field of 2.2 T and a field gradient of 20.3 T/m are found to tilt toward the higher field direction, which is attributed to the paramagnetic property of the Co²⁺ion. In addition, twisted structures are recognized on the tube walls. The direction of the twist is right-handed in the case that the higher field direction is parallel to the field direction and left-handed in the anti-parallel case. Observing the growth of the tubes in situ under magnetic fields has revealed that two cusps of silicate proceed revolving around at the growing end to form a tube wall double-helically. We have proposed a model for the mechanism of the helix formation that Lorentz force exerted on anions (Cl⁻) flowing through and out of the tubes would cause vortex around the growing ends and the vortex could strand the two cusps, which explains the twist direction with respect to the field direction reasonably.

A study of an effect of the magnetic levitation on polymerization of N-isopropylacrylamide at room temperature was carried out. The magnetic levitation environment, which is created by strong and upward magnetic force counterbalanced with the downward gravitational force, is multiple environment consisting of both the microgravity and the strong magnetic field which is lacking in a space vehicle orbiting around the earth. In this work, the effect was evaluated from the viewpoint of the number-average molecular weight (M_n) and the polydispersity (the index of the molecular weight distribution) of the synthesized polymer. A small extent (∼10 %) of the effect was observed on both the parameters. When the polymer was synthesized under the magnetic levitation environment, M_nincreased while the polydispersity decreased as compared with those of the polymer synthesized under the gravity.

Flow behaviour has been observed in binary alkali phosphate glass melts (xR₂O-2P₂O₅: R = Li, K ; x = 1, 3) under vertical magnetic field up to 3 T. The flow velocity of thermal convection decreased gradually to about one-third of the velocity at 0 T with an increase in magnetic field up to 1 T in the melt of low alkali content glass, and reached the constant value, under the condition of BdB/dz < 0. In contrast, the flow velocity was almost unchanged in the melt of high alkali content glass up to 3 T. On the other hand, the flow velocity decreased gradually to half of the velocity at 0 T with an increase in magnetic field in the melts of high alkali metal content glasses up to 3T, under the condition of BdB/dz> 0. The velocity decreased more gradually in the lithium containing melt than in the potassium containing melt. It was deduced from these observations that the flow behaviour under magnetic field was the resultant of balance between the thermomagnetic convection under the gradient of field and the electro-magnetic force by induced current.

Minimum field intensity required to achieve alignment of solid grains, which posses small diamagnetic anisotropy (Δ_χ)_DIA, is discussed based on observed values of hexagonal ice I_h; the field intensity is about 6 Tesla at T = 273K for ice I_h crystal with 1.0 μm in diameter. Grain alignment essentially require strong magnetic field above several Tesla when (Δ_χ)_DIA is in the level of 10⁻¹⁰ emu/g. (Δ_χ)_DIA arises from preferential orientation of individual chemical bond with respect to a magnetic principle axis of the solid body. Hence (Δ_χ)_DIA is negligibly small for materials with high crystal symmetry, such as crystals having a rutile, wurtzite or perovskite structure. Alignment should be studied intensively in high magnetic-field for these types of materials. Whereas alignment occurs below B = 2T for most of the unmeasured diamagnetic crystals with lower symmetry, since their (Δ_χ)_DIA values are expected to exceed 1 × 10⁻⁹ emu/g according to the above-mentioned model; this field is produced by an ordinary electromagnet.

The Berlin Neutron Scattering Center BENSC at the Hahn-Meitner-Institute (HMI) is a user facility for the study of structure and dynamics of condensed matter with neutrons and synchrotron radiation with special emphasis on experiments under extreme conditions. Neutron scattering is uniquely suited to study magnetic properties on a microscopic length scale, because neutrons have comparable wavelengths and, due to their magnetic moment, they interact with the atomic magnetic moments. Magnetic interactions and magnetic phenomena depend on thermodynamic parameters like magnetic field, temperature and pressure. At HMI special efforts are being made to offer outstanding sample environments such as very low temperatures or high magnetic fields or combination of both. For the future a dedicated instrument for neutron scattering at extreme fields is under construction, the Extreme Environment Diffractometer ExED. For this instrument the existing superconducting magnets as well as a future hybrid system can be used. The highest fields, above 30 T will be produced by the planned series-connected hybrid magnet system, designed and constructed in collaboration with the National High Magnetic Field Laboratory, Tallahassee, FL.

X-ray powder diffraction experiments under pulsed magnetic fields were carried out at the DUBBLE beam line at the ESRF. A mobile generator delivered 110 kJ to the load coil, which was sufficient to generate peak fields of 30 T. A liquid He flow cryostat allowed us to vary the sample temperature accurately between 8 K and 300 K. Powder diffraction patterns of TbVO₄ were recorded in a broad temperature range using 21 keV monochromatic X-rays and an on-line image plate detector. We present results on the suppression of the Jahn-Teller structural distortion in TbVO₄by to the magnetic field.

A review is given of the neutron scattering studies on a frustrated spinel antiferromagnet CdCr₂O₄. As observed in ZnCr₂O₄, which has been most extensively studied in the Cr-based spinel oxides, CdCr₂O₄ also shows an antiferromagnetic phase transition and a structural phase transition simultaneously, indicating a strong spin-lattice coupling. The magnetic structure of CdCr₂O₄was determined by neutron scattering studies. The neutron scattering study in magnetic field up to 10 T indicates an orientation of magnetic domains.

Synchrotron X-ray and neutron experiments in high magnetic fields have been performed using miniature pulsed magnets. In EuNi₂(Si_0.18Ge_0.82)₂, the drastic change of the L₃-edge absorption spectrum is found at the valence state transition. While, no changes of the spectra are found at the insulator-metal transitions in Kondo insulators YbB₁₂ and Ce₃Bi₄Pt₃. As a test experiment the high field neutron diffraction experiment of MnF₂has been carried out at JRR-3M reactor.

X-ray diffraction studies have been performed up to 38 T in conjunction with synchrotron x-ray beams and a split-pair pulse magnet at the beamline BL19LXU of SPring-8. The magnet consists of coaxial two-coils which are made by winding CuAg wire up to 18 layers. The magnet has four windows with wide aperture angles and the height of 3 mm for passage of the x-ray beam. A pixel array detector was used to measure the diffraction patterns during an exposure of 5 millisecond around the peak field. The details of the instrumentations are presented.

A new type of pulse magnet, x-ray and neutron transparent pulse magnet, is suggested for use in high-field diffraction experiments. The magnet is made of aluminumbased material, so we expect that the scattered beam penetrates the magnet body and hence the total number of reflection points available substantially increases. This feature possibly allows full determination of the lattice and magnetic structure in strong magnetic fields. To realize this idea, we constructed a prototype transparent magnet consisting of aluminum wire and duralumin reinforcement. With a portable capacitor bank, the maximum field of 25 T was successfully generated in a 1.6 mm bore, even though the aluminum wire is less strong and less conducting than copper wire. Since the total energy is small (E_bank ∼ 100 J), high repetition rate, which is necessary for sufficient signal-to-noise ratio, is realized. Technical details, coil performance, and future prospects will be described.

Single-crystal x-ray diffraction experiments on the geometrically frustrated magnet CdCr₂O₄ have been carried out under pulsed magnetic fields up to 31 T. By applying magnetic fields, CdCr₂O₄ exhibits a magnetization plateau which is one-half of the saturated magnetization above 28 T, and it is expected that a structural transition from a tetragonal to a rhombohedral or cubic structure occurs simultaneously through a so-called "spin Jahn-Teller" mechanism. Our diffraction experiments confirmed that a sharp structural transition occurs at 28 T and that the 440 reflection is a single peak, suggesting that the crystal structure of the high-field plateau phase is cubic.

Aiming at realising neutron scattering experiments under B = 40T magnetic fields, we are developing diffusive techniques for neutron diffraction with a long pulse magnet. For the present experiments, we succeeded in observing the spin-flop transition of the antiferromagnet MnF₂ around B = 10T using a 20T pulsed magnet on a neutron spectrometer installed at a reactor. 35T pulsed magnetic fields were also successfully generated.

Magnetic field-effect on spin-density-wave (SDW) order was studied for the single crystals of La_2−xBa_xCuO₄ with x = 0.10 (T_c = 24 K) and x = 0.125 (T_c < 5 K) by neutron-scattering measurements. At zero field, incommensurate peaks from both SDW and charge-density-wave (CDW) orders were observed below 40 K (50 K) in the former (latter) sample. Applying the field of 10 T perpendicular to the CuO₂ plane, the magnetic intensity in the x = 0.10 sample was enhanced with the rate of 20% of that at 0 T, while in the x = 0.125 sample no obvious field-effect on SDW order was confirmed under the field up to 10 T. These results suggest that the magnetic field induces enhancement of static SDW order in the superconducting sample and does not affect the well-stabilized SDW order in the non-superconducting sample of the LBCO system at x ∼ 1/8.

Scanning tunneling microscopy/spectroscopy (STM/STS) is a powerful method to investigate the spatial variation of electronic states with an atomic resolution. The energy resolution of STM/STS is also very high, better than ∼meV, which enable us to study the details of low-lying quasi-particle excitation spectrum. In addition, STM/STS works even in extreme environments e.g. at low temperatures and under high magnetic fields. Taking these advantages into account, we have built a versatile STM/STS system working under combined extreme conditions of ultra-high vacuum, very-low temperature and high magnetic field. We apply this system to the study of strongly correlated electron systems in which subtle interplay among charge, spin and orbital degrees of freedom brings about various electronic phenomena. As one of the examples, we describe the evolution of the tunneling spectrum across the metamagnetic transition in Sr₃Ru₂O₇.

Development of non-destructive pulsed magnet aiming at 100 T-generation beyond 80 T-field is our mission. For that purpose, we have been developing a new coil system, socalled "dual coil system" and succeeded in generation of 85 T. This magnet will open the nondestructive 100 T-field in the near future. New type of magnet with longer pulse duration also has been developed. This magnet has a gap between the inner coil and the outer one where liquid nitrogen can flow. Therefore, the magnet can be cooled down by liquid nitrogen rapidly. The repetition time has been reduced to 15 minutes for 60 T-field with the duration of about 30 msec. By means of this rapid-cooling technique, a magnet for X-ray diffraction measurement has been made. This magnet consists of split coils with a split gap of 5 mm and a duration time of about 30 msec. This magnet allows us to carry out X-ray diffraction measurement under pulsed high field. The maximum field of the magnet is found to be 38 T, which is limited by utilized energy of the capacitor bank.

Transient megagauss fields with a pulse length of few microseconds interact with sample material not only by the high field value but also by the extremely high dB/dt of ≈ 10⁸T/s. A large number of previously unexplained hysteretic phenomena can be attributed to this fact.

We have investigated the mechanisms for these complications experimentally as well as theoretically and demonstrate a quantitative analysis for InSb with estimates for the induced fields, eddy currents, "magneto form" processes and temperature dissipation.

A high-resolution resonant Raman spectroscopy system has been developed by using optical fibers and applied to the spin-flip Raman scattering experiment in CdZnTe/ CdZnMnTe quantum wells at ³He temperature in a high magnetic field up to 14 T. Excitation light from an external cavity laser diode or Ti:sapphire laser was introduced into the liquid ³He chamber by using polarization maintain fiber, and was incident on the sample at the angle of 45 degree through a GRIN collimation lens and a prism to deflect the reflected light from the luminescence/scattering detection pass. Luminescence and scattered light were collected efficiently into the bundled multi-mode fibers through a high NA objective lens and introduced into the slit of a 1.26 m single grating spectrometer equipped with a multi-channel CCD detector and a photon counter. The fiber system provides a convenient way to investigate the spin dynamics in an ideal environments; ultra-low temperature and radiation-free condition. Furthermore, the system is more sensitive than the conventional system utilizing a cryostat with the optical windows where multiple Fresnel loss and the small numerical aperture degrade the sensitivity.

Magnetic fields of over 100 T can be generated only through the use of a destructive pulsed magnet. Electro-magnetic flux compression (EMFC) is an efficient method to generate such ultra-high magnetic fields. The EMFC system at Institute for Solid State Physics holds the world record for the highest magnetic field produced in-doors. This system has been used for various sorts of measurements applied to matters under ultrahigh magnetic fields. Recently, we successfully improved the coil system to generate a higher field using less energy injection and more simplified preparation processes. The new system increased the electro-magnetic energy transfer efficiency to at least twice that of the previously employed system. Our new primary coil using a copper current guide has the advantage of shallower high-frequency current skin depth and less contact impedance than previous ones. Therefore the discharge current spark is completely avoided. The improved skin depth resulted in a symmetric implosion of the liner coil with less influence of the feed gap. A high degree of cylindrical liner symmetry was observed during implosion. A fast liner speed of 2.4 km/s was achieved, and 350 T could be generated by 1 MJ and 470 T by 2 MJ.

Magnetic field processing is a new promising tool for the structural and functional control of materials. A significant potential exists for tailoring microstructures and impacting kinetics of phase transformation in steels. A high magnetic field modifies the Gibbs free energy. As a result, the phase diagram is shifted upwards so that the A_c1 and A_c3temperatures increase as the magnetic field is increased. In this work, a new device for the heat treatment and in situ control of the transformation is described. For the first time, a dilatation measurement is used to study the shift of the ferrite/austenite equilibrium in high magnetic field up to 16 T and to quantify the ferrite concentration during the transformation. Experimental results for the transformations in pure iron are presented. Comparisons are made with the expected values based on the Weiss molecular field model near the Curie point.

The understanding of electromagnetic phenomena is based on the historic landmark A Treatise on Electricity & Magnetism of 1873 by James Clerk Maxwell. The form in which the theory is most commonly expressed is in the form of the vector equations introduced by Gibbs.

There is another more general formulation due to Élie Cartan, in terms of external differential forms. We will develop the description of electromagnetic phenomena using these concepts. It is a pre-metric description of conservation laws, that will highlight the basic properties of the electromagnetic phenomena. We will in particular demonstrate the fundamental role of the flux quantum Φ₀ = h/2e, and point to ways to calibrate magnetic fields.

High power THz-frequency material processing has great potential for the applications. The gyrotron is a microwave tube capable of delivering very high microwave power in the pulse and CW operation at the THz frequencies. The frequency of gyrotron is proportional to the intensity of magnetic field, because the operation results from the mechanism of "cyclotron resonance maser". Therefore, in order to achieve high frequency operation, we need a high magnetic field which superconducting magnets or pulsed-magnets produce. We developed the material heating system by using a 300 GHz gyrotron. This system consists of a 300 GHz, 3.5 kW, CW gyrotron (Gyrotron FU CW I) with a cryogen-free 12 T superconducting magnet, a corrugated circular waveguide and an applicator.

Sub-THz gyrotron series named 'Gyrotron FU Series' developed in Research Center for Development of Far Infrared Region, University of Fukui (FIR FU) has achieved the maximum frequency of 889 GHz with the output power of several hundred watt and has been successfully applied to plasma diagnostics and material physics. Recently, a THz gyrotron with a pulsed magnet has been designed, constructed and operated in FIR FU. The gyrotron has achieved the first experimental result for high frequency operations whose radiation frequency exceeds 1 THz. In this paper, the design detail and the operation test results for sub-terahertz to terahertz range are described. The second harmonic operation is confirmed experimentally at the expected frequency of 1.01 THz due to TE_6,11cavity mode at the magnetic field intensity of 19.1 T.

Dielectric polarization P (∥[110]) of a single crystal of a triangular lattice antiferromagnet CuFeO₂ has been measured by pyroelectric technique in pulsed high magnetic fields up to 43 T applied along the [001] direction. Among the five phases successively appeared in magnetic fields, a finite P is observed only in the non-colinear incommensurate (5-sublattice like) phase. The present results indicate that no inversion symmetry breaking occurs in the 4th field-induced phase where a non-colinear spin structure is expected.

Magnetostriction gives an insight into the interactions between the electronic and the lattice system of solids. Because only macroscopic methods can be used in fields above 20 T, miniaturized capacitive dilatometers were adapted to the strongest magnets. We performed experiments up to the highest available steady fields of 45 T and in 50 T pulsed field systems. The power of magnetoelastic investigations is illustrated by measurements at two 4f-intermetallics: SmCu₂ is an antiferromagnet below 23 K with a nearly compensated magnetic moment and, the monopnictid GdSb orders antiferromagnetically at 24 K. Both materials show magnetic transitions at applied fields of about 30 T when the ferromagnetic state is induced.

We have developed a high field and high pressure ESR system including a unique pressure calibration method. We have succeeded in the ESR measurements up to 16 T under the pressure region up to 1.1 GPa. We will present about the ESR system and its application to a spin gap system KCuCl₃. The energy gap between the singlet ground state and the triplet excited states are suppressed with applying pressure and the critical pressure of KCuCl₃is estimated to be 0.90 GPa at 4.2 K.

An extraction-type magnetometer has been developed, which is performed under pressures up to 12 kbar using a miniature high-pressure clamp-cell, in magnetic fields up to 270 kOe using our hybrid magnet and at the temperature range from 1.5 to 300 K. Magnetization curves can be measured for absolute value over 0.04 emu. We confirmed that resolution is about ±0.01 emu under high pressures and high magnetic fields if a sample has the magnetic moment of about 3 emu. For demonstrating the ability of the instrument, high field magnetization curves for SmMn₂Ge₂under high pressures are presented.

Trial measurements of magic-angle-spinning (MAS) NMR at 30T have been performed with a hybrid magnet of National Institute for Materials Science. A MAS-NMR probe was modified for a top-loading usage with the hybrid magnet. Speed of MAS ranges up to 15.5 KHz. In order to examine effects of inhomogeneity of the field on spectra, MAS-NMR measurements were performed using 4 mm sample holders with different sample size. A pipe of aluminum metal was used as a shield for the field fluctuations. A fourier-transformed ⁷⁹Br-MAS-NMR spectrum of KBr was obtained from a single shot measurement of a freeinduction- decay (FID) signal. The spectrum shows a spinning-side-band structure demonstrating a high resolution measurement.

We have developed a new Multi-Frequency (MF) ESR system for the frequencies between 35 to 130 GHz utilizing TE₀₁₁ single mode resonators. Their sensitivities (10¹⁰spins/G at 1.5 K) are comparable to that of a conventional low frequency ESR resonator and an order of magnitude higher than that of a Fabry Perot resonator which was previously developed by us. Thanks to a newly developed precise and stable matching system, we observed for the first time MFESR spectra of a metalloprotein with an integer spin.

A MOS-FET dropper was developed in place of a transformer coupled regulator in the active filter system of the 15 MW DC power supply to reduce the fluctuation to be lower than 10ppm at the Tsukuba Magnet Laboratory, National Institute for Materials Science.

The current status of the pulsed-magnet program of the Dresden High Magnetic Field Laboratory (HLD) is reported. The non-destructive pulsed magnets for the HLD include a wide spectrum of coils designed for energies between 1 and 46MJ, magnetic fields of 60 - 100T, and pulse durations of 10 - 1000 ms. Various experimental techniques at pulsed magnetic fields will be available for external users soon. Some user magnets for first scientific experiments have been installed and tested. A 8.5MJ/70 T mono-coil magnet has been built and first test results for this magnet are presented. The design of a two-coil 46 MJ magnet for magnetic fields above 85T has been completed. This magnet is under construction now. Important issues of the coil design are numerical simulations of the pulsed-magnet performance. Both analytical approaches and finite-element analysis are used for these simulations at the HLD.

The hybrid magnet (HM) at the Tsukuba Magnet Laboratory (TML) generates 35 T in a 52-mm warm bore with a field uniformity of about 6500 ppm in a 10 mm diameter sphere volume (DSV). A new resistive insert magnet with the same bore was designed to provide the higher field uniformity in the HM operation and the construction was started. This emagnet is composed of three concentric Bitter coils. The height of the outer coil is almost equal to that of present insert, . Tand the middle coil is made of a split-paired winding; . Tthe split gap is 53 mm. The A uniformity better than 10 ppm in a 10 mm DSV will be achieved at a themagnetic field of 34.0 T in a backup field of 14 T. This eimprovement in uniformity, in conjuncllaboration with theimprovements of the DC power supply already in progress at the TML, will make it possible to expand the application fields of the HM of the TML.

Micro-coil pulsed magnet system has been constructed with a single turn coils fabricated by photolithograph method on a printed circuit board. For the current switches, several different types of fast turn-on switches such as MOSFET switches, air-gap switches and optically triggered air-gap switches were tested and compared their properties. With 2100 V of charging voltage, about 10T of magnetic field was successfully generated at more than 1 Hz of repetition frequency. For the application of the micro-coil system to solid state physics, possible are discussed.

The High Field Magnet Laboratory at the Radboud University in Nijmegen provides DC magnetic fields up to 33 T to a European-wide user community since May 2003. Starting from 2006 the HFML will be part of the Nijmegen Center for Advanced Spectroscopy (NCAS), a consortium focused on using a broad range of spectroscopic tools in high magnetic fields for nanoscience, and supported by the Innovation Platform of the Dutch Government. NCAS will develop a 45 T hybrid magnet system with 32 mm room temperature access in conjunction with a free electron laser, which will provide far-infrared electromagnetic waves in the range 100 μm − 1.5 mm (0.2 − 3 THz). In this contribution we will give an overview of the considerations for the hybrid magnet, and we will in particular list the options that are under discussion for the realization of the new hybrid magnet system.

The design of pulsed magnets is discussed on basis of calculations with the PMDS code (Pulsed Magnet Design Software), both for coils with constant winding density and with optimised internal reinforcement by fibre composites. The importance of determining material properties is pointed out, and a proposal is made for the development of a system that allows measurement of material properties under realistic conditions as they are present in pulsed magnets.

International Laboratory of High Magnetic Fields and Low Temperatures, Wroclaw, Poland is financed by the Bulgarian Academy of Sciences, National Academy of Sciences of Ukraine, Polish Academy of Sciences and Russian Academy of Sciences as the main contributors. But the scientists from Germany, UK and other countries are also users of the Laboratory facilities. The Laboratory offers the measurements of the magnetic, transport and some optical properties, and magnetostriction both in permanent magnetic fields (Bitter and superconducting coils) up to 20 T, and in quasi-pulsed magnetic field up to 55 T with pulse duration of about 0.1 s in the temperature range 0.7–300 K.

The long-pulse magnetic field facility of the Laboratorio de Magnetismo - Instituto de Ciencia de Materiales de Aragón (Universidad de Zaragoza-CSIC) produces magnetic fields up to 31, with a pulse duration of 2.2s. Experimental set-ups for measurements of magnetization, magnetostriction and magnetoresistance are available. The temperature can be controlled between 1.4 and 335 K, being the inner bore of the He cryostat of 22.5 mm. Magnetization is measured using the mutual induction technique, the magnetostriction is determined with the strain-gage and the capacitive cantilever methods, and the magnetoresistance is measured by means of the aclock-in technique in the 4-probes geometry. An overview of the facility will be presented and the presently available experimental techniques will be discussed.

The magnetic field of the high field ESR system in Kobe University has been extended to 55 T by using a new non-destructive pulse magnet and the 300 kJ (10kV) capacitor bank. The properties of new 55 T pulse magnet are reported. As an example of its application, the high field ESR measurement of a quantum spin system CsCuCl3 for H∥a will be shown.

The high field facility in Frankfurt, founded in November 1994, uses a computercontrolled capacitor bank with a stored energy of 800 kJ. Today fields up to 58 T with pulse durations of 24 ms are achieved. One goal of the research activities has been the experimental development of a phase-sensitive method for the simultaneous detection of the ultrasound velocity and attenuation in pulsed magnetic fields. In addition, ESR experiments can be performed in Faraday- and Voigt geometry in the frequency range from 30 - 440 GHz, and the extension to high frequencies up to 1.5 THz is possible using a FIR laser system. Numerous experiments on strongly correlated systems have been performed - a few examples will be presented - demonstrating the significance of these powerful tools.

We report on the recent progress made at the Dresden High Magnetic Field Laboratory (Hochfeld-Magnetlabor Dresden = HLD). This facility, under construction at the research center (Forschungszentrum) Rossendorf, is planned to open as user facility in 2007 offering access to various pulsed-field magnets. Besides the ultimate goal of constructing a multi-pulse magnet reaching 100T in a bore of 20mm with a peak-pulse duration of about 10 ms, further self-designed high-energy coils will be provided. For thermodynamic experiments, e.g., a pulsed coil for 60T in 40mm and 1 s is planned. The necessary energy of up to 50MJ for coil operation recently became available through a world-unique capacitor bank working at 24 kV. First user-type magnets for fields up to 71T for 100ms in a bore of 24mm have been tested successfully. As an outstanding feature of the laboratory, the bright light of a next-door free-electron-laser facility will allow dedicated high-field infrared spectroscopy. A broad range of experimental techniques is being developed both for user and in-house research in static and pulsed magnetic fields.

Austromag offers high magnetic fields for various applications in solid state physics. The quasistatic high field facility gets the power (10 MWs) from the line of the city, reaching 40T in a long pulse (up to 1s). Additionally exist various short pulse facilities (pulse duration between 10 and 100 ms) which are energized by a condensor battery. New types of high field magnets (foil coil) were developed. Measurements are possible between 4.2 K and 800 K. The main experiments are: magnetization, magnetoresistence, anisotropy and magnetostriction. New measuring techniques were developed such as pressure dependence of anisotropy and magneto-electric coefficient.

The EC supported a network (under the Framework 5 ALFA Programme) designated HIFIELD (Project number II0147FI) and entitled: "Measurement methods involving high magnetic fields for advanced and novel materials". As a result, high field facilities were initiated, constructed or extended at the following laboratories in Latin America: University Cordoba (Argentina), CES, Merida (Venezuela), CIMAV, Chihuahua (Mexico), University Federal de Rio de Janeiro (Brazil).

A hybrid magnet needs a large amount of liquid helium for operation. In order to make an easy-to-operate hybrid magnet system, we constructed a cryocooled 28 T hybrid magnet, consisting of an outer cryocooled 10 T superconducting magnet and an inner traditional water-cooled 19 T resistive magnet. As a performance test, the cryocooled hybrid magnet generated 27.5 T in a 32 mm room temperature experimental bore.

As long as Nb3Sn superconducting wires are employed, the expected maximum high field generation in the cryocooled superconducting magnet will be 17 T at 5 K. We adopted the high temperature superconducting insert coil, employing Ag-sheathed Bi₂Sr₂Ca₂Cu₃O₁₀superconducting tape. In combination with the low temperature 16.5 T back-up coil with a 174 mm cold bore, the cryocooled high temperature superconducting magnet successfully generated the total central field of 18.1 T in a 52 mm room temperature bore.

As a next step, we start the collaboration with the National Institute for Materials Science for the new developmental works of a 30 T high temperature superconducting magnet and a 50 T-class hybrid magnet.

The 'Laboratoire National des Champs Magnétiques Pulsés' (LNCMP) is an international user facility providing access to pulsed magnetic fields up to and beyond 60 T. The laboratory disposes of 10 magnet stations equipped with long-pulse magnets operating in the 35–60 T range and a short-pulse system reaching magnetic fields in excess of 70 T. The experimental infrastructure includes various high and low-temperature systems ranging from ordinary flow-type cryostats to dilution refrigerators reaching 50 mK, as well as different types of high-pressure cells. Experimental techniques include magnetization, transport, luminescence, IR-spectroscopy and polarimetry. The LNCMP pursues an extensive in-house research program focussing on all technological and scientific aspects of pulsed magnetic fields. Recent technical developments include the implementation of 60 T rapid-cooling coils, an 80 T prototype, a pulsed dipole magnet for optical investigations of dilute matter and a transportable horizontal access magnet for small angle x-ray scattering experiments. Scientific activities cover a variety of domains, including correlated electron systems, magnetism, semiconductors and nanoscience.

The Humboldt High Magnetic Field Center is operated by the Chair for Magnetotransport in Solids of the Department of Physics of the Humboldt-Universität zu Berlin. It provides DC-magnetic fields up to 20 T, pulsed nondestructive fields of up to 60 T and megagauss fields of up to 331 T using a single-turn coil generator for experimental application focusing on solid state physics. Magneto-optical investigations are carried out in the MIR, NIR and visible wavelength range as well as transport and magnetization experiments.

The facility is open to the scientific community and welcomes users within the European project EuroMagNET. The laboratory will be closed in fall 2006 but its experimental facilities will be further accessible to the community in other labs. The single-turn coil generator will be transferred to LNCMP, Toulouse, France, continuing to provide applicable megagauss fields to the European Community.

The National High Magnetic Field Laboratory, established in 1990 with support from the National Science Foundation, the State of Florida, and the US Department of Energy, is a facility open to external users around the world. The experimental capabilities are distributed in three campuses. In Tallahassee, Florida, continuous magnetic fields are produced by means of superconducting and resistive magnets reaching fields of up to 33T (resistive), and 45T (hybrid). EMR, ICR, and a 900MHz wide bore NMR magnet are also available. The facility in Gainesville, Florida, is devoted to generating extremely low temperatures in the presence of external magnetic fields (15T, down to 0.4mK), and large MRI imaging capabilities. In Los Alamos, New Mexico, a 9 kV-capable capacitor bank and a number of different liquid Nitrogen-cooled resistive magnets produce repetitive pulses up to 75 T and now a single-shot pulsed up to 300T.

After brief introduction of history and facility of the High Magnetic Field Laboratory at KYOKUGEN in Osaka University, we describe our high field and multi-frequency electron spin resonance (ESR) apparatus by utilizing pulsed and superconducting magnets for the fields up to about 60 T. For the ESR measurements in pulsed magnetic fields, several Gunn and backward oscillators, and a far infrared laser are used as millimeter and submillimeter wave sources. In steady magnetic fields up to 16 T, we have utilized a vector network analyzer with extensions which covers the frequencies between 8 and 700 GHz almost continuously. The latter ESR apparatus is used not only dense magnetic materials but also weak ones, such as metalloproteins. Therefore, we have developed high sensitive multi-frequency ESR apparatus. To extend ESR studies further, we are now constructing ESR apparatus for much higher fields up to 70 T and the wide frequency range up to 7 THz. Magnetization and transport measurements are also performed in high magnetic fields up to 70 T and 60 T, respectively and magnetization measurements under high pressure up to 1 GPa. We plan to develop a 50 T wide bore pulsed magnet with the diameter of about 50 mm for the use of high sensitive ESR and high pressure measurements above 1 GPa.

The Tsukuba Magnet Laboratory (TML) has been a user facility for external users since April 1998 and contracted 91 collaborative studies with external research groups in the 2005 fiscal year. Internal and external researchers use high magnetic fields for magnetic processing as well as extreme-environment measurements. In 2006, two major changes were made to expand the experimental possibilities. One was the replacement of the helium liquefaction system, and the other was the remodelling of the 15 MW DC power supply. TML has also built an NMR complex including a 930 MHz and a 920 MHz NMR spectrometer. We have also started a collaborative study on high-field magnet development with the High Field Laboratory for Superconducting Materials. The projects include the development of a 30 T class superconducting magnet and a 50 T class hybrid magnet.

The pulsed field facility at the Katholieke Universiteit Leuven has recently been incorporated in the new Institute for Nanoscale Physics and Chemistry. The tradition of fruitful co-operation with other research groups has been further pursued. The laboratory has a magnet testing station and five user-friendly measuring stations that can be operated in parallel. Principal measuring techniques are magneto-transport, magnetization and photoluminescence; the research topics are high temperature superconductors, molecular magnets, diluted magnetic semiconductors, low dimensional metals, quantum dots and wires. The laboratory has established close co-operation with the LNCMP at Toulouse; in the context of large European facilities it has the status of a satellite user facility.

The Grenoble High Magnetic Field Facility (GHMFL) is open to the international scientific community. It can produce steady magnetic fields on 3 magnet sites with a 24MW power supply and on 6 sites with 12 MW. One of the 24 MW sites is designed to reach 40T in a future hybrid arrangement. The two other sites give either 33T in a 34mm bore diameter or 29T in 50 mm. The GHMFL has developed the use of helix inserts made of copper alloy tubes cut by spark erosion. This technique allows making high field magnets with more stable mechanical and electrical behaviors than by the 'Bitter' technique. Based on this technique a 14 helix insert powered by 11 MW was developed. It was first tested in 2002 and is now in operation on one of our three 24 MW site giving access to 33 T. In parallel a 8 helix insert with enhanced homogeneity was developed taking advantage of the possibility offered by the helix technique to make a variable pitch along the main axis. It gives access to a field of 20 T in a 160 mm bore. In 2006, a new high field version of the 14 helix is under construction and expected to reach 34 T. This technology will also be used for the design of a magnet with homogeneity of the order of 10 ppm on a sphere of 1cm3 (with extra shimming). This magnet will be dedicated to high resolution NMR studies.

This fiscal year in 2006, the mega-gauss laboratory at Kashiwa, Japan has changed the organization for the purpose of strengthening the high-magnetic field community in Japan. The new facility is composed of two main sections; one is the destructive pulse magnetic field facility with the single turn coil and the electro-magnetic flux compression systems. The part other covers the non-destructive long-pulse magnet coil systems. Our facility will introduce 210 MJ flywheel DC power generator for a 100 T project. Our recent scientific and technological developments are to be briefly described in conjunction with the new projects.

The RHMF2006 conference is placed in the context of the entire series of symposia, The number of papers presented in different topics has been compiled for all conferences.