Born-Mayer approach to the hydrogen potential in C-15 Laves phase compounds

Abstract

The potential wells seen by hydrogen in several interstitial sites in the C-15 Laves phase compounds ZrTi2, ZrCr2 and TiCr1.85 have been investigated using incoherent inelastic neutron scattering (IINS) data. Parameters describing the harmonic terms in the H-potential well in the three compounds are obtained from the first localized hydrogen vibrations as measured by IINS. The H-potential well is created by the sum of the pairwise potentials between the hydrogen and the four metallic atoms forming the different types of tetrahedral sites which are labelled (A2B2), (AB3) or (B4) in the C-15 structure. A Born-Mayer potential has been used to model these pairwise interactions with parameters determined from the IINS data. It has been shown that the hydrogen potential well can be described by parameters characteristic of each metal.