HRTEM study on the ordered phases in Hg3In2Te6 crystals grown by Bridgman method

Abstract

High-resolution transmission electron microscopy (HRTEM) is used to investigate Hg₃In₂Te₆ (MIT) crystals grown by the Bridgman method. The results show that at least two new ordered phases exist in the crystals. Their corresponding superstructure spots 1/3{422} and 1/6{422} are observed for the first time in defect zinc-blende crystals. The possible structural models of the two ordered phases are suggested based on HRTEM images. A mechanism is proposed to explain the formation and evolution of the two ordered phases. It is thought that the disorder–order phase transformation was not absolutely prevented during the furnace cooling process, due to the small cooling rate and the low thermal conductivity of the defect zinc-blende materials.