The diffusivity of sintered material was determined by using radiotracer and microtoming techniques at -45 to 18C. The results could be described by:

D (cm2/s) = 6.3 x 10-3 exp[-0.30(eV)/kT]

F.Beniere, J.I.Franco, J.P.Louboutin: Radiation Effects, 1983, 75[1-4], 139-44