Metal Hydrides focuses on the theories of hydride formation as well as on experimental procedures involved in the formation of hydrides, the reactions that occur between hydrides and other media, and the physical and mechanical properties of the several classes of hydrides. The use of metal hydrides in the control of neutron energies is discussed, as are many other immediate or potential uses, e.g., in the production of high-purity hydrogen and in powder metallurgy. It is hoped that this book will serve as a valuable reference to students, research professors, and industrial researchers in metal hydrides and in allied fields. Selected chapters may serve specialists in other fields as an introduction to metal hydrides. The information contained herein will also be of lasting and practical value to the metallurgist, inorganic chemist, solid-state physicist, nuclear engineer, and others working with chemical or physical processes involving metal-hydrogen systems.

The study of metal hydrides opens up promising avenues for the solution of world energy problems, as well as casting light on the interactions of hydrogen with materials, the role of hydrogen in materials science, and the chemistry of metal hydrides, all of which are discussed in this book in terms that range from a global look at the new vision of energy and how hydrogen fits into that future to reviews such as a look at nickel hydride over the last 40 years. Very specific current research in such areas as hydrogen in materials science discuss properties like superconductivity, diffusion EMF, magnetic properties, physicochemical properties, phase composition, and permeability. Hydrogen can also be used as a processing or alloying agent, and in the synthesis of battery electrodes, composite materials and alloys. The interaction of hydrogen with many metals, composites and alloys offers potential hydrogen storage systems. There is also a discussion of hydrogen sensors.

This book has been conceived to collect the most important recent advances in all areas of hydride chemistry research, including chemical reactivity, instrumental investigation, theory, and applications in the areas of catalysis, biochemistry and materials science. Many of the chapters have been written by the plenary lecturers of the EURO-Hydrides 2000 conference, but other leading scientists in this field have also been invited to contribute. The first part of the book focuses on the chemistry and catalysis of transition metal hydrides. Another block of chapters illustrates the most recent advances in the application of instrumental techniques to the study of the properties and reactivity of hydride compounds. The final part of the book illustrates the relevance of metal-hydrogen bonds in biochemistry and materials science. All of the chapters of this book have been evaluated by independent reviewers.

Hydrides: Types, Bonds and Applications first proposes metal hydrides as a fascinating class of compounds due to the small mass and size of hydrogen. Its medium electronegativity causes a large flexibility in terms of metal-ligand interactions, resulting in a vast variety of possible compositions, chemical bonding, crystal structures and physical properties. However, numerous unsolved problems remain on our way towards a sustainable, carbon free energy system based on renewable energy and on hydrogen as a future energy carrier. Thus, the authors present the structural details of alkali, alkali earth based selected tetra-boro hydrides. Selected hydrides have recently been suggested for applications in optoelectronics and as solid electrolytes for battery applications. Their use in optoelectronic devices depends on their stability with respect to doping, solubility of shallow donors and acceptors, electrical and optical properties. The authors describe the nature of the bonding in hydrides, and show how these affect the properties of these materials, focussing on application in the energy storage and in the transportation sector. Next, the features of gas discharge and plasma sources based on Penning trap with metal hydride cathodes are presented. In such devices, metal hydrides fulfill the functions of both a cathode and the solid-state generator of working gas. The authors determine that hydrogen desorbed from metal hydride significantly changes the properties of the discharge. This is expressed, for example, in the fact that the plasma source based on Penning trap with metal hydride cathode appears to generate current-compensated ion beams with the ability to control the energy of the extracted ions. Lastly, the book discusses metal hydrides obtaining in sintered electrodes of nickel-cadmium batteries with electrochemical methods by the way of electrolyte decomposition onto hydrogen and oxygen. It was shown that as a result of electrolyte decomposition, oxygen releases from batteries, while hydrogen partly releases and is partly (in virtue of its high diffusion permeability) accumulated in sintered matrices of electrodes of nickel-cadmium batteries in the metal hydrides form.

In the last five years, the study of metal hydrides has ex panded enormously due to the potential technological importance of this class of materials in hydrogen based energy conversion schemes. The scope of this activity has been worldwide among the industrially advanced nations. There has been a consensus among researchers in both fundamental and applied areas that a more basic understanding of the properties of metal/hydrogen syster;,s is required in order to provide a rational basis for the selection of materials for specific applications. The current worldwide need for and interest in research in metal hydrides indicated the timeliness of an Advanced Study Insti tute to provide an in-depth view of the field for those active in its various aspects. The inclusion of speakers from non-NATO coun tries provided the opportunity for cross-fertilization of ideas for future research. While the emphasis of the Institute was on basic properties, there was a conscious effort to stimulate interest in the application of metal hydrides to solar/hydrogen energy conver sion schemes in land areas where solar energy has promise as a primary energy source. In addition to the lectures, several seminars were given which treated topics of special interest in greater detail.

In September, 1999, with the generous support of NATO, scientists from 18 different nations gathered in Katsiveli, Yalta, Ukraine at the NATO Advanced Research Workshop on Hydrogen Materials Science and Chemistry of Metal Hydrides to present their research and to discuss world energy problems and possible solutions, interactions of hydrogen with materials, the role of hydrogen in materials science, and the chemistry of metal hydrides. High level and highly professional presentations were accompanied by a great deal of discussion and debate of the issues from both fundamental and global perspectives. The result was a large number of new collaborations, new directions, and better understanding of energy and materials issues. The research presented at this meeting can be found in this volume. These papers range from global perspectives such as the new vision of energy and how hydrogen fits into that future, to reviews such as a look at nickel hydride over the last 40 years, to very specific current research. A large number of papers are included on hydrogen and materials. These papers include articles on properties such as superconductivity, diffusion EMF, magnetic properties, physico chemical properties, phase composition, and permeability as a result of the interaction with or incorporation of hydrogen. Also included are papers discussing the use of hydrogen as a processing or alloying agent. The use of hydrogen in the synthesis of battery electrode materials, composite materials, and alloys is also presented.

Ames Laboratory, Iowa, USA

This book is a printed edition of the Special Issue "Functional Materials Based on Metal Hydrides" that was published in Inorganics

The 2001 International Conference «Hydrogen Materials Science and Chemistry of Metal Hydrides» (ICHMS'2001) was held in the picturesque town Alushta (Crimea, Ukraine) on the bank of Black Sea in September 16-22, 2001. In the tradition of the earlier ICHMS conferences, the 7th ICHMS'2001 provided an international forum for the presentation and discussion of the latest research on transition to hydrogen-based energy systems, technologies for hydrogen production, storage, utilization, materials, energy and environmental problems. The aim of ICHMS '200 1 was to provide an overview of the latest information on research and development in the different topics cited above. The representatives from industry, public laboratories, universities and governmental agencies could meet, discuss and present the most recent advances in hydrogen concepts, processes and systems, to evaluate current progress in these areas of investigations and to identify promising research directions for the future. The ICHMS'2001 was the first conference in this series, where a related new important topic of considerable current interest on fullerene-related materials as hydrogen storage was included into the conference program. The hydrogen sorbing properties of newly discovered carbon nanostructural materials inspire hydrogen scientists with optimism. Thus, the ICHMS'2001 conference was unique in bringing together hydrogen and carbon materials researchers and engineers from developed countries of Europe and America, new independent states of FSU and other countries for discussions in advanced materials development and applications.

Metal hydrides are of inestimable importance for the future of hydrogen energy. This unique monograph presents a clear and comprehensive description of the bulk properties of the metal-hydrogen system. The statistical thermodynamics is treated over a very wide range of pressure, temperature and composition. Another prominent feature of the book is its elucidation of the quantum mechanical behavior of interstitial hydrogen atoms, including their states and motion. The important topic of hydrogen interaction with lattice defects and its materials-science implications are also discussed thoroughly. This second edition has been substantially revised and updated.