Thermodynamic investigations of HgTe

Abstract

The free energy of formation of HgTe has been determined by an electrochemical technique using an SbCl3KCl + 5wt.%Hg2Cl2 molten electrolyte. In the temperature range 340-410 K, the ΔG°f vs. T relationship (ΔG°f = -36545 + 20.54T J mol-1) has been established for the reaction Hg(l) + Te(s) = HgTe(s). The free energy, heat and entropy of formation have been calculated at 298 K. Estimation of the ΔG°f vs. T relationship in the higher temperature range corresponding to the reaction Hg(g) + Te(1) = HgTe(s) indicates that HgTe decomposes prior to melting. By differential thermal analysis it has been confirmed that HgTe decomposes at 873 K. The thermodynamic results are discussed in terms of structure and bonding of the compound. © 1990.