Abnormal thermal expansion and thermal conductivity of CuIn-=SUB=-7-=/SUB=-Se-=SUB=-11-=/SUB=- single crystals

Abstract

Homogeneous CuIn7Se11 single crystals with a diameter of ~14 mm and length of ~ 40 mm have been grown from the melt using the Bridgman method. Composition and structure of the obtained single crystals have been defined. It was shown that the obtained single crystals crystallized in a hexagonal structure. The anisotropy of thermal expansion and thermal conductivity in the temperature range of 80-650 K has been investigated on oriented single crystals in parallel and at right angle to the main crystal axis c. Abnormal thermal expansion and thermal conductivity were observed on the single crystals oriented in parallel to the main crystal axis. Keywords: Bridgman method, single crystals, crystalline structure, thermal expansion, thermal conductivity.