Investigation into T-x-y projection of the P-T-x-y phase diagram of the Pb-Sn-Te system

The coordinates of the surface of liquidus, solidus and vapour in the T-x-y projection of system Pb-Sn-Te have been specified. The surface of solidus limits the region of homogeneity of the solid solution. Stannum concentration determines the width of the prohibited zone, whereas the difference (ysup(s)-0.5) determines the type of conductivity and concentration of the main current carriers. The homogeneity region of the solid solution with the increased content of stannum is displaced towards tellurium. At certain concentrations of stannum the stoichiometric section (y=0.5) extends beyond the limits of this region. At various concentrations of tellurium the isothermic lines of the liquidus are consistent with the data given in other publications devoted to this problem. The gaseous phase, as compared to the liquid phase, is rich in tellurium both in the region of PbTe-Te-SnTe and in the region of Pb-PbTe-SnTe-Sn