Irreversible behavior on electrical resistivity in the fast-Li-ion conductor LiA1

The temperature-dependent electrical resistivity above 300 K of $\ensuremath{\beta}\ensuremath{-}\mathrm{L}\mathrm{i}\mathrm{A}\mathrm{l}$ is presented. An irreversible behavior of electrical resistivity was observed around 600 K. It is proposed that an abrupt decrease in electrical resistivity is associated with the decrease of effective scatterers induced by the formation of Li vacancies at elevated temperature. The irreversible electrical resistivity is discussed in terms of Li out-diffusion and antisite defects (both Li on the A1 sublatice and A1 on the Li sublattice).