Dehancement effect of Ag on Ag diffusivity in Pb(Ag) alloys

The effect of Ag concentration on Ag diffusivity in dilute Pb(Ag) alloys was measured between 150 and 204°C and no significant enhancement or dehancement was found. This lack of dehancement in the Pb(Ag) system, in sharp contrast to Pb(Au), indicates that Ag singlet defects do not associate to doublet defects in the concentration and temperature regime investigated. The solubility of Ag in Pb was determined in the course of the investigation and its temperature dependence was described by the dilute-solution theory equation $1\mathrm{n}{c}_{\mathrm{eq}}=\frac{\Delta \overline{s}}{R}-\frac{\Delta \overline{h}}{\mathrm{RT}}$, with $\Delta \overline{s}=9.61\mathrm{}\pm 0.56$ cal/mole K and $\Delta \overline{h}=12.0\mathrm{}\pm 0.3$ kcal/mole.