Large positive magnetoresistance effect below Curie temperature in In1.90-xMn0.1SnxO3

(Received 29 October 2006; accepted 23 January 2007; published online 11 May 2007)

We report on the magnetoresistance (MR) and magnetic properties of In1.90xMn0.1SnxO3 (0x0.06) oxide. All samples were found to be ferromagnetic below TC=46 K. Sn doping changed In1.90Mn0.1O3 from an insulator to a highly conducting phase at 300 K. A positive MR effect was observed over a wide temperature range just below TC. Calculated MR values reached a maximum of 20% at 5 K. A change in the MR effect, from positive to negative, occurred under magnetic field H>4 T at 5 K. The results of x-ray absorption near-edge spectroscopy indicated that Mn ions are present both as Mn2+ and Mn4+. é2007 American Institute of Physics