Solid‐state quaternary phase equilibrium diagram for the Hg–Cd–Te–O system

• Published in: Journal of vacuum science & technology. A, Vacuum, surfaces, and films Vol. 1; no. 3; pp. 1712 - 1718
• Main Authors: Rhiger, David R., Kvaas, Robert E.
• Format: Journal Article
• Language: English
• Published: 01-07-1983
• Subjects: raman spectroscopy; phase diagrams; phase equilibria; oxidation; medium temperature; cadmium oxides; chemical reactions; tellurium oxides; cadmium tellurides; formation free enthalpy; mercury oxides; mercury tellurides; stability
• ISSN: 0734-2101; 1520-8559
• DOI: 10.1116/1.572214

For the Hg–Cd–Te–O system an approximate three‐dimensional diagram of quaternary phase equilibrium at room temperature has been constructed for the first time, to aid in the study of Hg1−x
Cd
x
Te surface oxides. Thermodynamic calculations based on standard Gibbs energies of formation were performed to determine which phases are mutually stable. Stability relationships were checked by reaction experiments in mixtures of bulk reference compounds, using Raman spectroscopy for analysis. Elemental Hg is shown to coexist in equilibrium with all of the oxide and telluride phases. Thus, it is likely to be present whenever oxidation is incomplete. CdTeO3 is shown to be stable with respect to the other oxides and tellurides. Several instabilities are indicated, in which an oxide can react with the Hg1–x
Cd
x
Te to release elemental Hg or Te, or HgTe.