An investigation was made of self-diffusion by using ionic conductivity, tracer diffusion (serial sectioning) and drift mobility methods. The Na-diffusion data, for 640 to 790C, could be described by:

D (cm2/s) = 6.2 x 102 exp[-2.21(eV)/kT]

V.C.Nelson, R.J.Friauf: US Atomic Energy Commission Report COO-1197-30, 1968