In the last two decades low-dimensional (low-d) physics has matured into a major branch of science. Quite generally we may define a system with restricted dimensionality d as an object that is infinite only in one or two spatial directions (d = 1 and 2). Such a definition comprises isolated single chains or layers, but also fibres and thin layers (films) of varying but finite thickness. Clearly, a multitude of physical phenomena, notably in solid state physics, fall into these categories. As examples, we may mention: • Magnetic chains or layers (thin-film technology). • Metallic films (homogeneous or heterogeneous, crystalline, amorphous or microcristalline, etc.). • I-d or 2-d conductors and superconductors. • Intercalated systems. • 2-d electron gases (electrons on helium, semiconductor interfaces). • Surface layer problems (2-d melting of monolayers of noble gases on a substrate, surface problems in general). • Superfluid films of ~He or 'He. • Polymer physics. • Organic and inorganic chain conductors, superionic conductors. • I-d or 2-d molecular crystals and liquid crystals. • I-d or 2-d ferro- and antiferro electrics.

This is a textbook of what is often called magnetochemistry. We take the point of view that magnetic phenomena are interesting because of what they tell us about chemical systems. Yet, we believe it is no longer tenable to write only about such subjects as distinguishing stereochemistry from the measurement of a magnetic susceptibility over a restricted temper ature region; that is, paramagnetism is so well-understood that little remains to explore which is of fundamental interest. The major purpose of this book is to direct chemists to some of the recent work of physicists, and in particular to a lengthy exposition of magnetic ordering phenomena. Chemists have long been interested in magnetic interactions in clusters, but many have shied away from long-range ordering phenomena. Now however more people are investigating magnetic behavior at temperatures in the liquid helium region, where ordering phenomena can scarcely be avoided. The emphasis is on complexes of the iron-series ions, for this is where most of the recent work, both experimental and theoretical, has been done. The discussion therefore is limited to insulating crystals; the nature of magnetism in metals and such materials as semiconductors is sufficiently different that a discussion of these substances is beyond our purposes. The book is directed more at the practical experimentalist than at the theoretician.

This text presents a detailed view of the calculation methods involved in the magnetic properties of transition metal complexes. Starting at an elementary level, it proceeds gradually through theory and calculations to offer sufficient background for original work in the field. No specialized knowledge of magnetism is assumed in the introductory chapters, which offer basic definitions and generalizations of magnetic behavior and briefly review both crystal field theory and perturbation theory. Succeeding chapters explore calculations of the magnetic properties of cubic and axially distorted complexes. Featuring the complete calculation for spin-orbit coupling and magnetic field perturbations for one d-configuration, the text also discusses derivations and results for other configurations. Other topics include the magnetism of polynuclear species, in which antiferromagnetic ordering occurs over small numbers of centers. Detailed calculations by the dipolar coupling approach are given, and the results are applied to a number of studies from the literature.

This book is a Festschrift in honour of Professor Kazuko Motizuki on the occasion of her retirement from Osaka University. She has been active in a variety of branches of solid state physics and, in particular, has made an important contribution to the theory of magnetism. The book reviews recent advances in magnetism of transition metal compounds, both for itinerant electron systems and localized spin systems. For the former systems, band calculational methods, correlation effects, and theoretical aspects of photoemission spectroscopy are reviewed generally, and then recent progress in the theoretical and experimental understanding of magnetic properties of various kinds of intermetallic compounds and intercalation compounds of transition-metal dichalcogenides are reviewed in detail. For the latter systems, attention is focused on quantum effects, frustration and competing interaction in low-dimensional systems. Main subjects treated in the book are Haldane gap-systems, singlet-ground-state systems, triangular spin systems, and quantum spin chains with competing interactions.