The chemical diffusion coefficient of O in perovskite bronzes was measured by using the potentiostatic step method, with a solid-state electrochemical cell arrangement. This technique involved the use of a stabilized zirconia solid electrolyte which acted as both a pump and a sensor for O. The diffusion coefficient of O in La0.79Sr0.20MnO3 was found to be of the order of 10-7cm2/s at 700C, and 10-6cm2/s at 860C (for O partial pressures of between 0.21 and 10-8atm. Preliminary measurements of La0.5Sr0.5MnO3 yielded a value of 2 x 10-8cm2/s at 840C.

A.Belzner, T.M.Gür, R.A.Huggins: Solid State Ionics, 1990, 40-41, 535-8