The self-diffusion of O at 710C under an oxygen pressure of 10-6atm was studied by using 18O tracer and secondary ion mass spectrometry techniques. It was found that, near to the surface, volume diffusion from the surface predominated. Under these conditions, the bulk diffusion coefficient was 2 x 10-14cm2/s. The grain boundary contribution predominated at points which were more distant from the surface. It was deduced that the grain boundary diffusivity was 2 x 10-17cm3/s.

F.Perinet, M.Schuhmacher, C.Monty: Crystal Lattice Defects and Amorphous Materials, 1987, 16[1-4], 45-8