Metal–insulator transition in Cu 1− xZn xIr 2S 4 system

Abstract

We report on the effect of Zn substitution for Cu in CuIr 2S 4 spinel, which shows the metal–insulator (MI) transition at about 230 K accompanied with a cubic-to-tetragonal structural phase transformation. It was shown that the solid solution of Cu 1− x Zn x Ir 2S 4 can be formed for 0⩽ x⩽0.5. The MI transition temperature decreases rapidly with increasing Zn content, and no MI transition can be observed for x>0.3. The magnetic susceptibility in metallic state decreases with the Zn substitution, suggesting a hole-filling mechanism. Low-temperature X-ray diffraction revealed that the tetragonal distortion of insulating phase decreased with increasing Zn content.