A modified mass-loss measurement technique was used here, for the first time, to make direct  in situ  determinations of metal vacancy formation in (Hg0.8Zn0.2)1-xTex. The metal vacancy concentrations were determined, at temperatures of between 350 and 650C and for 4 different compositions within the homogeneity region, and were found to range from 1.7 x 1019 to 6.6 x 1019/cm3. The formation enthalpy of a singly-ionized metal vacancy was deduced to be between 0.32 and 0.72eV; depending upon the deviation from stoichiometry. When compared with published data on HgTe, the present results revealed a slight but significant increase in the enthalpy of vacancy formation in going from HgTe to Hg0.8Zn0.2Te. These data provided the first direct experimental evidence, in terms of vacancy formation energy, which supported theoretical predictions of the bond-strengthening effect of Zn in the HgZnTe system. On the basis of simultaneously determined equilibrium Hg partial pressures within the homogeneity range, the vacancy concentration versus partial pressure isotherms were constructed. The Hg partial pressures were also measured along the 3-phase boundaries of the solid solution. It was found that these were in close agreement with data which had been obtained by means of optical absorption measurements.

The Direct Determination of the Vacancy Concentration and P-T Phase Diagram of Hg0.8Zn0.2Te by Dynamic Mass-Loss Measurements. Y.G.Sha, H.Wiedemeier: Journal of Electronic Materials, 1990, 19[11], 1303-12