Magnetic properties and electron-transport properties in Fe0.92Cr2S4

Sample of Fe0.92Cr2S4 has been studied with Mossbauer spectroscopy, X-ray p hotoelectron spectroscopy (XPS), SQUID magnetometer. and magnetoresistance (MR). The crystal structure was cubic spinel with its lattice constant a(0) = 9.9925(2) Angstrom. The maximum MR ratio was observed at 183 K about 12% under 1.6 T. The Mossbauer spectra were recorded from 18 K to room tempera ture. Below the Curie temperature the asymmetric line broadening is observe d and considered to be dynamic Jahn-Teller distortion. Isomer shift value o f the sample at room temperature was 0.53 mm/s, which means that charge sta te of Fe ions is ferrous in character. The conduction mechanism in this sam ple is different from the double exchange mechanism in a point that there w ere no mixed iron charge valences. (C) 2001 Elsevier Science B.V. All right s reserved.