Hydrogen in Intermetallics I is the first of two volumes aiming to provide atutorial introduction to the general topic of hydrogen in intermetallic compounds and alloys. In the present volume, a series of chapters, each written by two experts in the field, gives a comprehensive review of thefollowing areas: -preparation of intermetallics and their hydrides on a laboratory and industrial scale; - thermodynamic properties; -crystal and magnetic structure; - electronic properties; - heat of formation models; - magnetism and superconductivity.

The topic of hydrogen in an on metals and alloys is important in a number ofdisciplines including solid-state physics, materials science, physical chemistry, and energy technology. This volume treats the dynamics of hydrogen in intermetallic compounds, surface properties, kinetics, and applications of metal hydrides in energy technology. In addition, selected experimental methods are described. The introductory chapter will enable non-specialists to gain an overall picture of the field and to appreciate the relevant scientific issue. The companion volume, Hydrogene in Intermetallic Compounds I, was published as Vol. 63 of Topics in Applied Physics.

This Special Issue collects ten articles related to the broadly understood physical properties of intermetallic compounds. Differential thermal analysis was carried out, and the temperatures of thermal effects that arise during the reduction of neodymium from a technological salt mixture of KCl–NaCl–CaCl2–NdF3 with a magnesium–zinc alloy were established. For sol–gel products of stoichiometric MgTiO3, accurate thermal expansion coefficients were measured. The effect of various nanoparticles, such as GaF3, ZnF2, Zn(BF4)2 and Ga2O3 additions, on the activity of CsF-RbF-AlF3 flux and mechanical behavior of Al/Steel brazed joints is presented. The effect of Bi substitution on the structural and magnetic properties of Nd1-xBixMnO3 is investigated. Characteristics of hard magnetic materials based on Nd2Fe14B and Ce2Fe14B intermetallic compounds are presented. A special algorithm is presented to support vector regression for estimating the maximum magnetic entropy change of doped manganite-based compounds. We have received information about the mechanical properties of the reactively synthesized porous Ti3SiC2 compound with different apertures. Furthermore, we have presented the experimental results of Zn-doped Al-rich for fast on-board hydrogen production.

Recent advances in electrochemistry and materials science have opened the way to the evolution of entirely new types of energy storage systems: rechargeable lithium-ion batteries, electrochroms, hydrogen containers, etc., all of which have greatly improved electrical performance and other desirable characteristics. This book encompasses all the disciplines linked in the progress from fundamentals to applications, from description and modelling of different materials to technological use, from general diagnostics to methods related to technological control and operation of intercalation compounds. Designing devices with higher specific energy and power will require a more profound understanding of material properties and performance. This book covers the status of materials and advanced activities based on the development of new substances for energy storage.

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.

It is well known that the density of molecular hydrogen can be increased by compression and/or cooling, the ultimate limit in density being that of liquid hydrogen. It is less well known that hydrogen densities of twice that of liquid hydrogen can be obtained by intercalating hydrogen gas into metals. The explanation of this unusual paradox is that the absorption of molecular hydrogen, which in TiFe and LaNis is reversible and occurs at ambient temperature and pressure, involves the formation of hydrogen atoms at the surface of a metal. The adsorbed hydrogen atom then donates its electron to the metal conduction band and migrates into the metal as the much smaller proton. These protons are easily accomodated in interstitial sites in the metal lattice, and the resulting metal hydrides can be thought of as compounds formed by the reaction of hydrogen with metals, alloys, and intermetallic compounds. The practical applications of metal hydrides span a wide range of technologies, a range which may be subdivided on the basis of the hydride property on which the application is based. The capacity of the metal hydrides for hydrogen absorption is the basis for batteries as well as for hydrogen storage, gettering, and purification. The temperature-pressure characteristics of metal hydrides are the basis for hydrogen compressors, sensors, and actuators. The latent heat of the hydride formation is the basis for heat storage, heat pumps, and refrigerators.

Ames Laboratory, Iowa, USA