Diffusion processes in defective crystals and multistate diffusion

A stochastic theory of multistate diffusion on defective lattices is introduced via a defect-dressed continuous-time random walk propagator. The method is employed for periodic defective lattices to analyze: multistate diffusion; the effects of lattice structure on diffusion constants; and variations in quasielastic neutron scattering line-shapes due to migration mechanisms. A new interpretation of anomalous vacancy diffusion, deviating from Arrhenius behaviour, due to competition between different monovacancy migration mechanisms is given.