Accession Number : AD0614292

Title :   PARTIAL PRESSURES AND GIBBS FREE ENERGY OF FORMATION FOR CONGRUENTLY SUBLIMING CDTE(C),

Corporate Author : MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB

Personal Author(s) : Brebrick,R. F. ; Strauss,A. J.

Report Date : 17 JUN 1964

Pagination or Media Count : 7

Abstract : The partial pressures of Cd(g) and Te2(g) over congruently subliming CdTe(c) between 780 and 939C were determined by measuring the optical density of the coexisting vapor at 2287, 3650, 4357 and 5000 A. It is found that p(Cd) = 2P(Te2) and log p(Te2)(atm) = - (10000)/ T + 6.346. The standard Gibbs free energy of formation of Cd sub (1 - x) Te sub x(c) from Cd(g) and Te2(g) is delta G (CdTe(c)) = - 68.64 + 44.94 (0.001)T kcal/mole, independent of composition. This expression agrees quite well with those which represent the data obtained in electro-chemical and effusion experiments at lower temperatures, although the equilibrium state studied in the present investigation is different from the steady state attained in effusion experiments. (Author)

Descriptors :   (*INTERMETALLIC COMPOUNDS, SUBLIMATION), (*SUBLIMATION, INTERMETALLIC COMPOUNDS), (*CADMIUM ALLOYS, TELLURIUM ALLOYS), (*TELLURIUM ALLOYS, CADMIUM ALLOYS), VAPOR PRESSURE, THERMODYNAMICS, SOLIDS, OPTICAL ANALYSIS, SCIENTIFIC RESEARCH, SPECTROPHOTOMETERS, SOLID STATE PHYSICS

Distribution Statement : APPROVED FOR PUBLIC RELEASE