Solute enhancement of silver self-diffusion in silver-tin alloys at low temperatures

Abstract

Measurements of the diffusion of ^110mAg in Ag-Sn alloys over the temperature range 618-654 K and 0 to 4.5at.%Sn have been carried out by means of the ion-beam sputtering technique for serial sectioning. A strong non-linear enhancement of solvent diffusion upon alloying was observed. The Gibbs free energy (-g _b1) of vacancy-impurity binding was calculated from the data. Comparison with earlier high-temperature measurements reveals that g _b1 decreases substantially with decreasing temperature. At 1000 K g _b1 = 0.20 eV is observed in good agreement with results from measurements of the absolute vacancy concentration.