The diffusivity of O was determined by using an electrochemical technique. The O-ion conductivity was measured under direct-current polarization and then converted into a diffusion coefficient by using a modified Nernst-Einstein equation. It was found that the data, at 412 to 800C, could be described by:

D (cm2/s) = 4.98 x 10-3 exp[-0.50(eV)/kT]

I.Kontoulis, B.C.H.Steele: Solid State Ionics, 1991, 47[3-4], 317-24