In this article, the solidus temperatures of the Hg1−xZnxTe pseudobinary phase diagram for several compositions in the lowxregion were measured by differential thermal analysis and the HgTe–ZnTe pseudobinary phase diagram was constructed. The densities of two HgZnTe melts,x=0.10 and 0.16, were determined by aninsitupycnometric technique in a transparent furnace over, respectively, 110 and 50 °C ranges of temperature. The thermodynamic properties of the melts, such as the heat capacity and enthalpy of mixing, were calculated for temperatures between the liquidus and 1500 °C by assuming an associated solution model for the liquid phase. ©1996 American Institute of Physics.