Determination of the energy of mixing of HgTe-CdTe solid solutions by diffuse X-Ray scattering

Abstract

The short‐range order of the HgTe‐CdTe (34 mol% CdTe) solid solution is studied by means of X‐ray diffuse scattering measurements. The mixing energy of the system is found to be (1.1 ± ± 0·2) kcal/mol for short‐range order in one of the sublattices by means of extrapolation of the long‐wave Fourier‐transform fluctuations of the concentration (Cq) to the point q=0. This parameter is used for a phase diagram calculation. The mixing energy is calculated by pseudopotential methods.

Mechanical and Thermal Properties

“…The differences between thermodynamic properties of Hg 1−x Cd x Te alloys and that of the other A 2 B 6 solid solutions are confirmed by Barlow [171] on the basis of the phase diagram calculation in the framework of a binary regular solutions model. Integral and excess thermodynamic functions for formation of the Hg 1−x Cd x Te solid solutions were first evaluated by Ilegems and Pearson [172] to give a better fit with the solidus and liquidus curves, then by Bublik and Zaitsev [173] with a pseudopotential method, and experimentally determined at room temperatures by Rugg et al [174], at 370 • C by Goncharuk and Sidorko [154], and at 462-567 • C by Nasar and Shamsuddin [139]. They show a positive deviation from ideality that confirmed the conclusion of Sidorko and Goncharuk [175].…”