Thermal expansion of ternary semiconductor compounds AgB3C26

Temperature dependences of elementary cell parameters, molar volume, main and mean coefficients of thermal expansion for crystals are determined, melting temperatures are improved characteristic Debay temperatures and some thermodynamic properties of AgGaSr, AgInS2, AgGaSe2, AgInSe2, AgGaTe2, AgInTe2 compounds are calculated, effect of anion (S-Se-Te) and cation substitutions on the change of these parameters is considered, using X-ray diffraction technique. It is shown, that within 80-650 K temperature range for AgB3C26 (B-Ga, In; C-S, Se, Te) with chalcopyrite tetragonal structure the thermal expansion coefficients along the direction, parallel to tetragonal axis, are negative, while along the perpendicular direction-positive ones. With temperature increase both main coefficients of expansion increase by absolute value, coefficients, characterizing thermal expansion anisotropy, grorespectively. AgGaSe2 compound has the largest anisotropy of thermal expansion, while AgInTe2 compound has the smalest anisotropy of thermal expansion, while AgInTe2 compound has the smalest anisotropy among the considered group of A1B3C26 ternary compounds