An  in situ  X-ray technique was used to study the diffusion of O in c-axis oriented films which had been prepared via radio-frequency magnetron sputtering. The diffusion was directed mainly parallel to the c-axis of the film, and the coefficients for O diffusion were estimated to be of the order of 10-14 and 10-12cm2/s for annealing temperatures of 500 and 900C, respectively.

E.Narumi, D.T.Shaw, M.Matsui, K.Yamamoto: Japanese Journal of Applied Physics, 1990, 29[5], L772-4