DETERMINATION OF THE ENHANCEMENT FACTOR OF SOLVENT DIFFUSION IN DILUTE SILVER-TIN AND SILVER-INDIUM ALLOYS AND CRITICAL CALCULATION OF THE VACANCY JUMP FREQUENCY RATIOS.

The enhancement of solvent diffusion as a function of the solute concentration was measured in single-crystalline samples of dilute Ag(In) and Ag(Sn) alloys. Two sets of 7 Ag(In) and 6 Ag(Sn) samples for each system with solute concentrations between 0 and 0. 9 at. % were simultaneously annealed at 1054 and 1052 K, respectively. Combining the calculated linear enhancement factor b//1//1 equals 17. 6 plus or minus 1. 8 (Ag(In)) and b//1//1 equals 20. 2 plus or minus 1. 3 (Ag(Sn)) with the corresponding correlation factors and the ratios of solute to self-diffusion, a spectrum of consistent sets of frequency ratios for vacancy jumps and the vacancy flux factors were calculated in terms of the five-frequency model. It was found that the vacancy flux factor reacts very sensitively on small uncertainties in the primary experimental data.