Revisiting SR studies of ion dynamics in the light of extended Kubo-Toyabe model

Ito, Takashi   ; Kadono, Ryosuke*

The dynamical Kubo-Toyabe (dKT) function is extended to describe the spin relaxation under the coexisting dynamical and static internal magnetic fields. A detailed re-evaluation of the previous SR data in NaCoO using this function disfavors the conventional interpretation based on sodium-ion diffusion and instead supports the self-diffusion scenario. This also resolves the long-standing inconsistencies in the dKT-function-based SR studies on ion diffusion from the viewpoint of classical over-barrier-jump mechanism.