Rare-earth borides have attracted continuous interest for more than half a century both from the point of view of fundamental condensed matter physics and for practical applications in various fields of engineering. They demonstrate a wealth of unusual electronic and magnetic properties that have been closely investigated in recent decades using advanced spectroscopies and state-of-the-art physical characterization methods. Authored by leading experts in the field, this book features a comprehensive collection of reviews offering a cutting-edge summary of the research on rare-earth borides from various viewpoints. It includes chapters on the growth and characterization of single-crystal and thin-film samples, detailed description of their lattice structure and dynamics, electronic and magnetic properties in the bulk and at the surface, low-temperature ordering phenomena, and theoretical and experimental description of the unusual spectroscopic properties from the perspective of modern x-ray and neutron scattering, Raman spectroscopy, and electron spin resonance. The book will appeal to anyone interested in the physics and chemistry of solids and low-temperature physics, especially to researchers and postgraduate students who study magnetic and electronic properties of rare-earth compounds.

The volume "Rare Earth Elements" C 11 deals with the compounds and systems of the rare earth elements with boron, Le., borides, borates, and associated alkali double compounds. As in all earlier volumes of "Rare Earth Elements" Se ries C ("Seltenerdelemente" Reihe Cl, comparative data are presented in sections preceding treatment of the individual compounds and systems. Topics of the present volume C 11 aare the comparative data on the borides and the indi vidual sections on the systems and borides containing Sc, Y, and La. The individual sections for the systems and borides with Ce to Lu can be found in the following volume C 11 b together with the borates, their alkali double compounds, and other compounds containing Ce to Lu, boron and elements related by the Gmelin system. The most extensively studied borides treated in the comparative sections are of the type MB. These rare earth hexaborides are refractory compounds and so me of them, especially e LaBe, are good thermionic emissive materials or exhibit other interesting physical properties.

Translated from: Uspekhi khimii (vol. 28, 1959), p. 189-217.

V. I. MATKOVICH During the meeting of the International Symposium on Boron held in October, 1972 in Tbilisi, U.S.S.R., the idea was proposed to assemble a review of boron and refractory borides by the specialists present. The advantages of such a work were immediately apparent. Such diverse applications of borides as in protective armor, nuclear reactors, coat ings, reinforcement, etc. can hardly all be presented in sufficient detail by a single author. On the other hand it was also recognized that with so much specialization, some areas of interest may not be covered. Within the last decade or two a number of areas have been developed in which the use of refractory borides is growing and improvements are being actively explored. Thus, a number of borides have considerable potential as reinforcing material for plastics or light metals, though only boron fibers have been firmly established up to the present. Ap plication of flakes and films for two-dimensional reinforcement appears attractive, although the high cost of materials and development repre sents a considerable barrier. A number of borides have been used to manufacture lightweight protec tive armor. In this area relatively fast changes seem to be taking place as improvements in performance and weight are made. Boron carbide has found considerable use in this application and new developments exploit the light weight of beryllium borides.