Anisotropic Thermal Expansion and Electronic Structure of LiInSe₂

Optical quality cm-sized LiInSe₂ crystals were grown using the Bridgman-Stockbarger method, starting from pure element reagents, under the conditions of a low temperature gradient of 5-6 degrees/cm and a slight melt overheating. The phase purity of the grown crystal was verified by the powder XRD analysis. The thermophysical characteristics of LiInSe₂ were determined by the XRD measurements in the temperature range of 303-703 K and strong anisotropy of the thermal expansion coefficients was established. The following values of thermal expansion coefficients were determined in LiInSe₂: α_a = 8.1 (1), α_b = 16.1 (2) and α_c = 5.64 (6) MK^-1. The electronic structure of LiInSe₂ was measured by X-ray photoelectron spectroscopy. The band structure of LiInSe₂ was calculated by ab initio methods.