A modified mass-loss measurement technique was used here, for the first time, for the direct  in situ  study of Hg vacancy formation in this solid. The Hg vacancy concentrations were determined, at temperatures of between 335 and 626C, for 4 different compositions within the homogeneity region. They ranged from 2 x 1019 to 7 x 1019/cm3. The formation enthalpy of a singly-ionized Hg vacancy was estimated to be between 0.29 and 0.54eV; depending upon the deviation from stoichiometry. Published thermochemical data on this quantity were in qualitative agreement with the present results. On the basis of the simultaneously determined equilibrium Hg partial pressure within the homogeneity range, the vacancy concentration versus partial pressure isotherm diagram was constructed (figure 19).

G.S.Yi, H.Wiedemeier: Journal of Electronic Materials, 1990, 19[2], 159-69

Figure 19

Vacancy Concentration versus Partial Pressure Isotherms for HgTe

a: 600C, b: 550C, c: 500C, d: 450C