Haven ratio and correlation effects in diffusion in li₃N

Abstract

We define a modified Haven ratio H_nmr using NMR-experiments instead of tracer diffusion techniques. The derived experimental values of Hnmr show that the anisotropic ionic conductivity in Li₃N can be completely described in terms of two diffusion processes determined from NMR observables: an intra-layer process within the Li₂N layers only and an inter-layer process involving both Li sites. The comparision of Hnmr obtained by a computer simulation with the corresponding experimental value confirm the idea of a vacancy-induced migration of Li ions in the Li₂N layers.