Diffusion of Cobalt into Silver

Abstract

The diffusion coefficient of cobalt into silver has been measured as a function of temperature over the range from 745°C to 943°C by the tracer and lathe-sectioning technique. It has been found that the diffusion coefficient can be expressed as follows;
D=(104)exp\frac59.9RT10³ cm²⁄sec.
The value of activation energy, 59.9K cal/mol, obtained by the present experiment is in good agreement with the result of the screening theory of impurity diffusion, but considerable discrepancy is found between the observed and theoretical frequency factor. The amount of diffused cobalt showes an abnormal decrease near the diffusing surface, which may be caused by the low solubility limit of cobalt in silver.