Research on Improved II-VI Crystals.

Ft. Belvoir Defense Technical Information Center JAN 1971.

119 p.

APPROVED FOR PUBLIC RELEASE.

Thermodynamic properties associated with the II-VI systems have been determined from various published data and from experimental work done here. Accurate vapor pressure equations have been obtained for Zn, Cd, S, Se, and Te. The phase diagrams of the Zn-S, Cd-S, Zn-Se, Cd-Se, Zn-Te, and Cd-Te systems have been established, although in some cases only tentatively. The temperature dependent equilibrium constants for the sublimation of ZnS, CdS, ZnSe, CdSe, ZnTe, and CdTe have been accurately evaluated. The component pressures at the solid stability field boundaries (P-T diagrams) of CdS, CdSe, ZnTe, and CdTe have been determined experimentally. The boundary pressures for ZnS and ZnSe are estimated by analogy. A theory of the constitution of the equilibrium liquid at the solid stability field boundaries invoking specific molecular species has been developed and applied to the Cd-Te system. The compositions at the solid stability field boundaries (x-T diagrams) of CdS and ZnTe have been tentatively evaluated. Some application of this basic information has been made in exercising control of II-VI crystal growth and treatment. (Author).

English

January 24, 2011