High-temperature oxygen diffusion in monocrystalline material was studied. Above 400C, the oxygen was readily exchanged with the sample environment. By changing the partial pressure of oxygen in the sample environment the O diffusion at selected temperatures was determined. In-diffusion was significantly faster than out-diffusion. The in-diffusion data was described by:

D(cm2/s) = 11.7 exp[-1.16(eV)/kT]

S.McKernan, A.Zettl: Physica C, 1993, 209[4], 585-90