Torsion effusion measurements of Hg pressure over condensed HgTe

The sublimation of HgTe occurs according to the process HgTe(s) -> Te(s)+Hg(g) The mercury pressures were measured by the torsion-effusion method in the temperature range 478-576 K. From comparison with the literature data, the temperature dependence of the mercury pressure can be expressed by the equation log P(kPa) = 8.18-5700/T. Treating the results by second (and third) law the average ?H0298 = 105 ± 4 kJ mol-1 associated with the vaporization process was derived. Comparison of the ?H0298 values obtained by the two laws showed that until the first step of the vaporization the solid tellurium residue can be considered to be near unit activity. The standard heat of formation of HgTe, ?H0f,298 = -4.4 kJ mol-1, was also derived.