Monte Carlo simulation of hydrogen diffusion in C15 Laves phase intermetallic compounds

We present preliminary results from Monte Carlo simulations of hydrogen diffusion in C15 Laves phase compounds. The incoherent quasi-elastic neutron scattering function, S-inc(Q, omega), is evaluated for the case of non-interacting particles diffusing on g-sites and is compared to the analytical model proposed by Rowe et al. [J.M. Rowe, K. Skold, H.E. Flotow, J. Phys. Chem. Solids 32 (1971) 41-54]. A good level of agreement, at low Q, is obtained when the tracer correlation factor is accounted for. A value of 0.00238 Angstrom(2) per Monte Carlo cycle is obtained for the tracer diffusion coefficient. A brief discussion of the extension of this simple model to include metal hydrogen interactions is also given. (C) 1999 Published by Elsevier Science S.A. All rights reserved.