Structural and Thermal Properties of Cu1 – xAgxInS2Chalcopyrite Solid Solutions

Abstract

The anisotropic thermal expansion of Cu1 – x AgxInS2chalcopyrite solid solutions was studied by x-ray diffraction from 80 to 650 K. Over the entire temperature range studied, the thermal expansion of the solid solutions was found to be anisotropic: thec-axis thermal expansion is considerably smaller than thea-axis thermal expansion. The solid solutions with 0.55 <x< 1.0 exhibit negative c-axis thermal expansion. The composition dependences of the thermal expansion coefficients and anisotropy parameters are nonlinear. The anisotropy parameters rise monotonically with increasing x. The correlation between the thermal expansion anisotropy and tetragonal distortion δ = 2 – c/ais considered. Directions of zero thermal expansion are identified.