Radiotracer methods were used, at 500 to 850C, under a minimum total pressure or saturated Cd pressure. The diffusivity was also studied as a function of the Cd pressure at 675, 750 or 850C. It was found that, above 700C and under a saturated Cd vapour pressure, the diffusivity could be described by:

D (cm2/s) = 5.8 x 10-2 exp[-1.85(eV)/kT]

Under the minimum total pressure, the diffusivity could be described by:

D (cm2/s) = 1.53 x 100 exp[-2.47(eV)/kT]

At temperatures below 700C, and under a saturated Cd vapour pressure, the diffusivity could be described by:

D (cm2/s) = 6.72 x 102 exp[-2.67(eV)/kT]

The higher-temperature results were explained in terms of a doubly ionized Cdi-related donor or a CdS defect diffusion mechanism. At lower temperatures, the results were tentatively explained in terms of a VCd-related mechanism.

D.Shaw: Journal of Physics C, 1984, 17[27], 4759-82

The best linear fits to the solute diffusion data ([5] to [25]) yield:

Ag: Ln[Do] = 0.44E – 11.0 (R2 = 0.93); Au: Ln[Do] = 0.43E – 15.2 (R2 = 0.82);

Cd: Ln[Do] = 0.47E – 23.8 (R2 = 0.94); Cu: Ln[Do] = 0.37E – 14.9 (R2 = 0.29)