Monte Carlo simulation of quasielastic neutron scattering from localised and long-range hydrogen motion in C15 Laves phase intermetallic compounds

Bull, DJ; Broom, DP; Ross, DK

Abstract

A number of cubic C15 Laves phase intermetallic compounds are able to absorb large amounts of hydrogen. At low solute concentrations, the protons occupy tetrahedral interstitial sites, which form a network of hexagons. It is believed that the motion of hydrogen occurs on two distinct time-scales; a rapid localised motion around the hexagons, coupled with a slower long-range diffusion between hexagons. Results from Monte Carlo simulations of hydrogen diffusion in a Laves phase compound are presented. It is demonstrated that the incoherent quasielastic neutron scattering function, obtained from the simulations, can be interpreted in terms of a broad and a narrow Lorentzian component, emanating from hydrogen motion on the two time scales. The narrower component follows a Chudley-Elliot model, indicative of long-range diffusion, whilst the broader component can be interpreted in terms of localised motion. The calculated effective jump length for long-range diffusion is significantly in excess of the actual jump-length, in agreement with experimental observation. The model is briefly discussed in relation to hydrogen diffusion in ZrV2H1.1.

Citation

Bull, D., Broom, D., & Ross, D. (2003). Monte Carlo simulation of quasielastic neutron scattering from localised and long-range hydrogen motion in C15 Laves phase intermetallic compounds. Chemical Physics, 292(2-3), 153-160. https://doi.org/10.1016/S0301-0104%2803%2900155-1

• Journal Article Type: Article
• Online Publication Date: Apr 18, 2003
• Publication Date: Aug 1, 2003
• Deposit Date: Aug 22, 2007
• Journal: Chemical Physics
• Print ISSN: 0301-0104
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 292
• Issue: 2-3
• Pages: 153-160
• DOI: https://doi.org/10.1016/S0301-0104%2803%2900155-1
• Publisher URL: http://dx.doi.org/10.1016/S0301-0104(03)00155-1
• Related Public URLs: http://www.journals.elsevier.com/chemical-physics/