The diffusion of 63Ni in single crystals of NiO was measured by using a sectioning method. For 1000 to 1470 in air,

D(cm2/s) = 1.83 7 x 10-3 exp[-45.6(kcal/mol)/RT]

J.S.Choi, W.J.Moore: Journal of Physical Chemistry, 1962, 66[7], 1308-11