Electronic Structure and Properties of Hydrogen in Metals

Hydrogen is the smallest impurity atom that can be implanted in a metallic host. Its small mass and strong interaction with the host electrons and nuclei are responsible for many anomalous and interesting solid state effects. In addition, hydrogen in metals gives rise to a number of technological problems such as hydrogen embrittlement, hydrogen storage, radiation hardening, first wall problems associated with nuclear fusion reactors, and degradation of the fuel cladding in fission reactors. Both the fundamental effects and applied problems have stimulated a great deal of inter­ est in the study of metal hydrogen systems in recent years. This is evident from a growing list of publications as well as several international conferences held in this field during the past decade. It is clear that a fundamental understanding of these problems re­ quires a firm knowledge of the basic interactions between hydrogen, host metal atoms, intrinsic lattice defects and electrons. This understanding is made particularly difficult by hyrogen's small mass and by the large lattice distortions that accompany the hydrogenation process. The purpose of the "International Symposium on the Electronic Structure and Properties of Hydrogen in Metals" held in Richmond, Virginia, March 4-6, 1982 was to increase our fundamental under­ standing of hydrogen in metals. Such knowledge is essential in solving technologically important questions. The symposium con­ sisted of twenty-two invited papers and seventy-two contributed poster presentations and attracted nearly 150 participants from thirteen countries. The proceedings of this symposium constitute this book.

Contenu

Phase Diagrams, Spinodals, and Thermodesorption.- Metal-Hydrogen Phase Diagrams.- A Review of the Statistical Theory of the Phase-Change Behavior of Hydrogen in Metals.- Spinodals and Spinodal Mechanisms in M-H Systems.- What is the Relevance of Thermal Fluctuations for the Spinodal Decomposition in a Coherent Metal-Hydrogen System?.- Enthalpy of Metal-Hydrogen Systems: A Pair-Bond Model.- Thermal Desorption Spectra of PdHx System (0 of Dilute Hydrogen in Pure and Defected Metals.- Structure and Phase Transitions in V2D and V2H.- Hydrogen Vibrations in Nickel Hydride.- Localized Vibrations of H in Nb and Ta at High Concentration and Low Temperatures.- Tetrahedral and Octahedral Site Occupancy and Optic Mode Vibrations of Hydrogen in Yttrium.- Influence of Substitutional and Interstitial Impurities on Local Hydrogen Modes in Nb.- Quasielastic Neutron Scattering in Metal Hydrides: Effects of the Quantum Mechanical Motion of Interstitial Hydrogen Atoms.- A Study of Hydrogen Site Occupation in the Yttrium-Hydrogen Solid Solution Phase Using Inelastic Neutron Scattering.- Neutron Scattering Studies of the Low Temperature Transition in ?' PdD.- Properties of Vanadium-Alloy Dihydrides.- Temperature Dependence of Intrinsic Disorder in LaHx and YHx.- Electronic Structure.- Electronic Structure of Metal Hydrides: A Review of Experimental and Theoretical Progress.- The Electronic Structure of PdHxStudied with Photoemission and Electron Energy Loss Spectroscopy.- XPS/UPS Study of the Electronic Structure of PdH0.6.- Electronic Structure of Metal Hydrides and Deuterides from de Haas van Alphen Measurements.- Electronic Structure of Non-Stoichiometric Transition Metal Hydrides.- A Simple Tight Binding Description of the Electronic Structure of a Single and a Pair of Hydrogen Atoms in fcc Transition Metals.- Theoretical Studies of Dilute Hydrogen Impurities in Palladium.- Electronic Structure of Interstitial Hydrogen in Aluminum.- Calculation of the Ground State Energy of Hydrogen at Interstitial Sites in a Lithium Cluster.- Parametrization of the Self-consistently Calculated Electronic Densities Around a Proton in Jellium.- Electronic Structure of Vanadium-Hydrogen Clusters.- Superconductivity.- Superconductivity in Metal-Hydrogen Systems.- Superconductivity in Metal Hyrides.- Effect of Structural Phase Transitions on the Superconductivity of PdHx(Dx).- Superconductivity and Hydrogen Depth Profiles in Electrolytically Charged Cu-Implanted Pd.- Superconducting Tunneling into Pd-Ni-D Alloys.- Resistivity and Electron-Phonon Coupling in Palladium Alloy Hydrides.- Superconductivity of Pd-Hx and its Connection with the Phase Diagram.- Magnetic Properties.- Magnetism of Mn, Fe, Co Impurities in PdHx as a Function of Hydrogen Concentration; Relation with the Electronic Structure of the Host.- The Magnetic Properties of GdxY6?xFe23 (x=0,1,2,3) Compounds and Their Hyrides.- Measurements of the Magnetization of Activated FeTi.- Jahn-Teller Resonance States in the Vb Metal Hydrides.- Hydrogenation Entropies of the ZrMn2+y System.- Hyperfine Interaction.- On the Electronic Structure of Hydrogen in Metals in the Light of Muon Knight Shift Measurements.- Anomalous Muon Knight Shift Behavior in a Cd Single Crystal.- The Hyperfine Field of the Positive Muons in the Ferromagnetic Transition Metals.- Hyperfine Field of Positive Muons Trapped at Monovacancies in Iron.- Pulsed ?SR Studies on ?+ in Metals.- Magnetic Susceptibility and Proton NMR Study of TiCr1.8Hx.- Proton NMR Studies of the Electronic Structure of ZrHx.- Nuclear Magnetic Resonance of Hydrogen in CeHx for x>2.- Diffusion.- Use of Nuclear Magnetic Resonance to Observe Diffusion of Hydrogen in Metals.- Diffusion of Hydrogen in Vanadium-Based Bcc Alloys.- The Effect of Magnetic Impurities on the Apparent Diffusion Coefficient of Hydrogen in Metal Hydrides Deduced from NMR.- NMR Studies of Hydrogen Diffusion in Palladium and ?-LaNi5 Hydrides.- Hydrogen Diffusion and Electronic Structure in Crystalline and Amorphous TiyCuHx.- Local Diffusion and Tunnelling of Trapped Hydrogen in Metals.- Extracting Maximal Information on Positive Muon Diffusion in Metals.- Effects of Impurities on the Diffusion of Positive Muons in Niobium.- Muon Diffusion in Noble Metals.- Diffusion of Positive Muons in Aluminum and Aluminum-Based Alloys.- Anomalous Behavior of Diffusion Coefficients of Hydrogen and Deuterium in High Content Palladium Hydride and Deuteride.- Proton Jump Rates in Palladium-Hydride 50-100K.- Theory of the Diffusion of Hydrogen in Metals.- Simple Small Polaron Model for the Hydrogen Concentration Dependence of Hydrogen Diffusion in Nb.- Transport Behavior of Dense Protons in a Slab.- Analysis of Hydrogen Permeation Experiments in 403 Stainless Steel.- Thermopower of ?-Phase PdHy.- Interaction with Defects, Chemisorption.- Direct Evidence for Interstitial and Vacancy-Associated Hydrogen Trapping Near Impurity Atoms in F. C. C. Metals.- Interaction of Hydrogen with Substitutional Solute Metals in the ?-Phase of the Palladium-Hydrogen System.- Deuterium Desorption and Host Interstitial Clustering in d-Irradiated Ni.- Trapping by Dislocations in ?'-PdDx Observed by NMR.- Positive PI-Mesons and Positive Muons as Light Isotopes of Hydrogen.- Behavior of Positive Muons Implanted in Iron Alloys.- Hydrogen Traps in Cold-Worked Palladium.- Influence of Hydrogen on the Direction of Crack Propagation in Iron Using Computer Simulation.- Theory of Hydrogen Chemisorption on Ferromagnetic Transition Metals.- Hydrogen Chemisorption on Closed-Packed Surfaces.- Magnetic Susceptibility, Proton NMR, and Muon Spin Rotation (?SR) Studies of an Unsupported Platinum Catalyst with Absorbed H and O.- Influence of Interstitial Hydrogen on Temperature Dependence of Electrical Resistance of Disordered Ni-Mn Alloys.- Hydrogen Absorption and Critical Point Lowering in Thin PdHx Films.- Summary.- Hydrogen in Metals 1982.- Participants.