Structural and magnetic properties evolution of Cu sub(2x) Cr sub(2x) Zr sub(2-2x) Se sub(4) for 0.500 less than or equal to x less than or equal to 0.650

Abstract

A series of compound Cu sub(2x) Cr sub(2x) Zr sub(2-2x) Se sub(4) with x = 0.500-0.650 were prepared by solid-state reaction in sealed quartz tubes. The Rietveld refinements of XRD patterns show that Cu sub(2x) Cr sub(2x) Zr sub(2-2x) Se sub(4) forms a solid solution of a single phase with the spinel structure (space group Fd -3 m). The lattice parameter (a) gradually decreases with increasing x from 0.500 to 0.625 but does not follow Vegard's law. Later, a increases for x is greater than 0.625. Our investigation revealed the development of clusters with short metal-metal distances. The variation of the cation distribution is discussed as per site preference and the Zr substitution. The magnetic properties of Cu sub(2x) Cr sub(2x) Zr sub(2-2x) Se sub(4) have been investigated for x = 0.525, 0.600, and 0.625 compositions using SQUID magnetometer. Temperature-dependent magnetic susceptibility indicates a spin-glass for x = 0.525 and 0.600 compositions, but a ferromagnetic ground state for x = 0.625 composition.