The migration of 54MnCl2 in pure single crystals was studied by using a vapor-phase source. An analysis of the concentration dependence of the diffusivity was carried out by using the Matano method. The apparent association enthalpy and entropy were found to be exceptionally large, and the diffusion data (table 126) could be described by the expression.

D (cm2/s) = 0.000587 exp[-0.889(eV)/kT]

It was suggested that the high association energy arose from second-nearest neighbor impurity-vacancy complexes.

W.A.Mannion, W.J.Fredericks: Crystal Lattice Defects and Amorphous Materials, 1987, 15[1-4], 289-94

Table 127

Self-Diffusion of Na in Single Crystals

of Pure NaCl in the Intrinsic Region