Temperature dependent Mössbauer and neutron diffraction studies of Cu x Fe1−x Cr2S4 compounds

Abstract

The cation distribution and magnetic structure of Cu x Fe1−x Cr2S4 (x=0.1, 0.2, 0.3, 0.4, and 0.5) has been studied by X-ray and neutron diffraction, vibrating sample magnetometer (VSM), and Mossbauer spectroscopy. The charge state of Fe is found to be ferrous (Fe2+) for the x=0.1 sample; ferric (Fe3+) for the x=0.5 sample; mixed state (Fe2+, Fe3+) for the x=0.2, 0.3, and 0.4 samples. The Mossbauer spectra of the x=0.1 sample show asymmetric line broadening, which is considered to be due to the Jahn-Teller effect of Cu2+ ions, and a symmetrical six-line pattern is shown for the x=0.5 sample. The valence state of the Cu ions for the x=0.1 and 0.5 samples is found to be divalent and monovalent, respectively. The magnetic structure of the samples was determined to be a ferrimagnetic structure with antiparallel alignment of the Fe and Cr ion magnetic moments.