Nanocrystalline materials are a topic of intensive studies as by physicists and chemists, as well as by material scientists last 15 years. This topic appeared due to new high-technology methods of production not only of powders but also of bulk or compacted materials with grain size down to 100 nm. Such materials have high density of grain boundaries and interfaces. The amount of atoms in grain boundaries consists tenth of atomic percent. This circumstance determined variation of physical and chemical properties of nanomaterials in comparison with coarse-grained materials with the same chemical composition. Another important circumstance of appearing of new properties is small grain size in nanostructured materials. As a result, the majority of such physical parameters, as distance between electrons of Cooper-pair in superconductors, length of exchange interaction in magnetics, mean free path in electric conductors, minimal distance between dislocations, etc., became lower than coherent length of atomic positions in nanocrystalline matter. All pointed features are considered in the present book in detail using numerous examples. For the first time the state of the art in the new science of nanostructured state is given in this book. The experimental results on influence of nanostructured state on the microstructure, mechanical, thermal, optical and magnetic properties of solids are surveyed. The main methods for preparing of isolated nanoparticles, ultrafine powders and compacted nanostructured materials are presented. Size effects in isolated nanoparticles and compacted nanocrystalline materials are discussed in detail. It is shown that the interfaces have an important part in the formation of structure and properties of compacted nanomaterials. Great attention is paid to diamagnetic and paramagnetic properties of weakly magnetic materials, such as Pd, Cu, and Ti. It is shown that the magnetic susceptibility increases up to 8 % due to vacancies or internal stresses appearing in the nanograins of these substances after severe plastic deformation. By measuring of magnetic susceptibility in situ the temperatures of recovery of coarse grained structure are determined. As a special issue of this book is refractory nonstoichiometric transition metal carbides MCy (M = Ti or V) which are interesting objects for studying atomic order and disorder in solid states. The possibility of ordering and disordering of atoms in transition metal carbides is ensured by strong nonstoichiometry. Nonstoichiometry gives rise to vacancies in carbon sublattice. In this book the interrelation between nanostructure and phase transformation in nonstoichiometric compounds is pointed out for the first time. Such approach opens the possibility to prepare nanostructure by exploring of phase transformation between phases with very different lattice constants. New methods for obtaining of nanostructure will be useful for goal-oriented fine tailoring of properties of nanomaterials based on nonstoichiometric compounds. This book will be interesting for specialists dealing with solid state physics, physical chemistry, solid state chemistry, and material science, as well as for postgraduate and PhD students of these specialities. 351 pp. References 944. Figures 111. Tables 10.
