Magnetic properties of CuCrZrSe4

Abstract We report on structural and magnetic properties of the spinel compound CuCrZrSe 4 . Rietveld refinement of the powder x-ray diffraction patterns reveals the normal spinel structure AB 2 Se 4 , where the Zr 4+ and Cr 3+ ions occupy the B sites, while the Cu 1+ ions are located on A sites. The magnetic susceptibility reveals a Curie–Weiss law above 250 K with a ferromagnetic Curie–Weiss temperature θ p = 115 K and an effective paramagnetic moment μ eff = 3.75 μ B per Cr 3+ ion corresponding to a g value g =1.94 in fair agreement with electron spin resonance (ESR) measurements. Below 100 K the magnetization deviates from the Curie–Weiss behaviour and splits into field-cooled (FC) and zero-field-cooled (ZFC) branches. A second anomaly in the magnetization close to 10 K, which is also visible in the ESR parameters, indicates the transition into a spin-glass state due to the random distribution of Zr and Cr ions on the B site. This is supported by the frequency dependence of the anomaly detected by AC susceptibility measurements.