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

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)

Document Details

Document Type
Technical Report
Publication Date
Jun 17, 1964
Accession Number
AD0614292

Entities

People

  • A. J. Strauss
  • R. F. Brebrick

Organizations

  • Massachusetts Institute of Technology

Tags

DTIC Thesaurus Topics

  • Chemistry
  • Effusion
  • Energy
  • Free Energy
  • Partial Pressure
  • Standards
  • Steady State
  • Vapor Pressure

Readers

  • Analytical Mechanics
  • Materials Science and Engineering.
  • Thermal Physics or Thermal Science.