THE THERMODYNAMICS OF INDIUM-VACANCY PAIRS IN HG0.79CD0.21TE

We have measured the thermodynamic properties of In-V(Hg) pair in the infrared material Hg0.79Cd0.21Te by using the method of perturbed angu lar correlation (PAC). PAC allows the determination of the absolute fr action of indium atoms in particular defects. Previous measurements ha ve characterized the In-V pairs with hyperfine interaction frequencies of 83 and 92 MHz. These defects were observed in materials which were quenched from > 350-degrees-C to retain a large number of metal vacan cies. After subsequent low temperature (60 < T(A) < 110-degrees-C) ann eals, the fraction of indium atoms that had trapped vacancies increase d because of the migration of metal vacancies. By measuring the rate o f increase at different temperatures, we determined the vacancy migrat ion energy to be E(m) = 0.45 +/- 0.04 eV. Anneals at slightly higher t emperatures dissociated the In-V pairs. From the decrease in the In-V pair fraction with temperature, the In-V pair binding energy was found to be E(b) = 0.44 +/- 0.15 eV.