The isotope effect E of a single jump vacancy diffusion mechanism in statically disordered lattices was investigated by Monte Carlo simulation. It was found that E decreased significantly with increasing disorder. This effect was attributed to percolation processes and ensuing reduction of the effective dimension of space for the diffusing particle.

Small Isotope Effect of Diffusion in Disordered Structures. N.P.Lazarev, A.S.Bakai, C.Abromeit, V.Naundorf: Physical Review Letters, 2002, 88[4], 045502 (4pp)