The chemical diffusion coefficient of polycrystalline samples of Ca-doped chromite was measured as a function of the O partial pressure, composition, and temperature by means of electrical conductivity relaxation. It was found that the measured chemical diffusivity increased with increasing O vacancy concentration, and the associated mechanism was explained in terms of defect chemical equilibrium. The vacancy diffusion coefficient which was derived was independent of the vacancy concentration. This suggested that the O vacancies were randomly distributed.

I.Yasuda, M.Hishinuma: Journal of Solid State Chemistry, 1995, 115[1], 152-7