Energetics and lattice contraction of [beta]-phase YH[sub 2+[ital x]]

Journal Article · Fri Apr 15 04:00:00 EDT 1994 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.49.10731· OSTI ID:5122341

Wang, Y; Chou, M Y ^[1]

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1. School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States)

The cubic YH[sub 2+[ital x]] system with an extended hydrogen composition is studied using the pseudopotential method and the local-density-functional approximation with a plane-wave basis. The study focuses on the [beta] phase with the metal atoms forming a face-centered-cubic lattice and the octahedral sites partially occupied by hydrogen for 0[lt][ital x][lt]1. The self-consistent total-energy calculation is performed by employing the supercell modeling method. The structural property, in particular, the volume contraction with increasing [ital x], is investigated by analyzing the energy changes for different site occupation. It is found that the lattice contracts mainly to increase the interaction of the additional electron and the metal [ital d] potential. In addition, the (420)-plane ordering of the [ital x]-excess hydrogen is examined for YH[sub 2.25] and is confirmed by energetics studies.

• DOE Contract Number: FG05-90ER45431
• OSTI ID: 5122341
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 49:15; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360202* -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
360204 -- Ceramics
Cermets
& Refractories-- Physical Properties
BINDING ENERGY
CRYSTAL DEFECTS
CRYSTAL LATTICES
CRYSTAL STRUCTURE
CUBIC LATTICES
ENERGY
HYDRIDES
HYDROGEN COMPOUNDS
INTERSTITIALS
LATTICE PARAMETERS
POINT DEFECTS
STOICHIOMETRY
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
YTTRIUM HYDRIDES