Effect of Hydrostatic Pressure on the Rate of Diffusion of Silver, Indium, and Antimony in Single Crystals of Silver

The rate of self-diffusion in silver and the rate of diffusion of indium-114 and of antimony-124 in silver were measured by the radioactive-tracer-lathe-sectioning technique at 910°C and at hydrostatic pressures up to 9.00 kbar. The diffusion rates were observed to decrease with increasing pressure and the activation volumes were determined to be 9.6 ${\mathrm{cm}}^3$/mole for self-diffusion, 9.1 ${\mathrm{cm}}^3$/mole for indium-114, and 8.5 ${\mathrm{cm}}^3$/mole for antimony-124. Thus the activation energies for self-diffusion and for electropositive impurity diffusion in silver should increase by approximately 0.2 kcal/mole per kbar. It was found that the difference in these values of activation volume could be explained by the Lazarus theory of impurity diffusion as modified by Le Claire. The limiting source of error was found to be the accurate measurement of the temperature of the diffusion anneal at high pressures.