Table of contents

The influence of an external magnetic field on the chemical and photochemical processes in molecular solids, semiconductors, photosynthetic systems, and liquid solutions, the magnetic (or nuclear-spin) isotope effect, the chemically induced magnetic polarization of electrons and nuclei, the radiofrequency chemical maser, the high-frequency magnetic-resonance modulation of the rates of physical and chemical processes involving paramagnetic particles, and magnetic effects in the molecular physics of gases—all these effects are a consequence of spin selection rules and spin evolution. In this review, we analyze the origin of magnetic spin effects, estimate their quantitative scale, and discuss the time scale of spin dynamics.

The new phenomenon of twinning plane superconductivity is reviewed. It has already been observed in several metals. The superconductivity is localized near a twinning plane and it appears at a temperature higher than the critical temperature of the superconducting transition of a bulk metal. The phase diagram for the twinning-plane superconductivity, plotted using the magnetic field and temperature as the coordinates, is very different for type I and type II superconductors. A detailed analysis of the experimental data on the twinning-plane superconductivity is accompanied by a theoretical description of the phenomenon. The presence of a dense twinned structure may increase considerably the critical temperature: for example, in the case of tin it has been possible to increase this temperature more than threefold. We shall discuss also the data showing that the twinning-plane superconductivity can play an important role in the recently discovered high-temperature superconductors.

A unit cell of a layer crystal may contain several layers and the atoms in these layers may interact with one another in different ways. The dependences of the forces of the interaction between the atoms on the distances separating them are also different. The deformation effects in crystals of this kind are unusual. This review reports experimental results obtained in studies of vibrational and electronic spectra of graphite and of layer semiconductors (mainly III–VI compounds) under conditions of elastic deformation at various temperatures. An analysis is made of the results of experimental investigations of thermal expansion of layer crystals. In each case a discussion is given of models which, on the whole, can provide a satisfactory explanation of the nature of the characteristic features of the observed effects.

A history of the discovery of electrical conductivity and of its realization is presented, based on 17th and 18th century primary sources. An account of the life of the discoverer of this phenomenon is given.

Two experiments of I. K. Kikoin—the correlation between superconductivity and the galvanomagnetic properties of metals (1933), and the gyromagnetic effect in superconductors (1938)—which were carried out long before the appearance of the microscopic theory of superconductivity, anticipated two of its principal conclusions. Established were: 1) the determining role of electron-phonon interaction; 2) the orbital nature of diamagnetism in superconductors.