Er2−xThxFe14B
(x = 0.0, 0.5, 1.0, 1.5, 2.0) polycrystalline compounds have been studied with
57Fe
Mössbauer spectroscopy, differential scanning calorimetry (DSC), magnetic measurements and
x-ray diffraction. Special emphasis was put on the spin reorientation phenomena (change of
spin orientation from planar to axial arrangement) occurring in this series when increasing
temperature. The spin reorientation in each compound has been investigated mainly by
narrow step temperature scanning in the vicinity of the spin reorientation temperature,
TSR.
Initial magnetization versus temperature measurements allowed us to establish the
temperature regions of reorientations and the Curie temperatures of the compounds. The
two-stage character of transitions was evidenced.
Mössbauer temperature scanning was performed with a step of 2 K in the vicinity of
TSR. The obtained spectra were analysed by using a procedure of simultaneous
fitting and the transmission integral approach. Consistent fits were obtained;
TSR
and the composition dependences of hyperfine interaction parameters were derived from fits
for all studied compounds.
DSC studies proved that the spin reorientations were accompanied by thermal effects for composition
x = 0.5. Transformation
enthalpy and TSR
were determined from these studies and the two-stage character of the transition was
confirmed.
The TSR
obtained with different methods were compared and the spin phase diagram for the series
was constructed.