Thermodynamically self-consistent approximations to the liquidus and solidus of Hg1−xCdxTe

Abstract

Based on liquidus and solidus temperatures and associated confidence limits reported by Brice, Capper, and Jones [J. Cryst. Growth, 75, 395 (1986)], we develop polynomial approximations to the liquidus and solidus curves for the pseudobinary material Hg1−xCdxTe. These approximations are “thermodynamically consistent” in that they satisfy the requirement that the liquidus and solidus temperatures must agree at x=0 and 1. A linear programming approach is used to find the lowest-degree polynomial approximations to the liquidus and solidus temperatures falling within the confidence limits of Brice et al. at each of their 21 compositions, and also satisfying the convexity requirement imposed by Brice et al. on their own manually-drawn curves. Finally, we present a twoparameter rational approximation that fits the tabulated segregation coefficients for Hg1−xCdxTe better than an earlier five-parameter polynomial approximation.