Precipitation of Te and Pb in PbTe Crystals

Precipitation rates of Te and Pb in supersaturated PbTe crystals have been studied in the temperature range from 180° to 400°C. The experimental results are interpreted as evidence that the dislocation and its interacting field may be considered as a simple cylinder sink with an effective capture radius $R$. The activation energy associated with precipitation was found to be 0.88 ev. Thermoelectric power measurements were used to monitor the precipitation process in $p$-type PbTe. Precipitation is shown to be a simple means for controlling the carrier concentration in nonstoichiometric crystals displaying retrograde solubility in their phase diagrams. From Hall data on near intrinsic crystals, the intrinsic carrier concentration and resistivity for PbTe are estimated to be $n_i=2\mathrm{}\times {10}^{16}/{\mathrm{cm}}^3$, and ${\rho }_i=0.2\mathrm{}$ ohm cm.