The behavior of Na was studied by using an electrochemical cell. It was found that the diffusivity could be described by:

D (cm2/s) = 4.4 x 10-4 exp[-16.3(eV)/kT]

at 240 to 440C.

D.Oakeson, A.V.Virkar: Journal of Materials Science, 1984, 19[1], 213-22