Abstract
The (La0.6Ca0.2Sr0.2MnO3)(1-x)(Sb2O3/CuO)(x) (x=0.00, 0.03, 0.07, 0.12 and 0.18) composites were prepared by the solid-state reaction technique. (La0.6Ca0.2Sr0.2MnO3)(1-x)(Sb2O3/CuO)(x) are identified by X-ray diffraction and SEM analysis as a two phases consisting of ferromagnetic manganite phase and Sb2O3/CuO phase. Magnetic measurement reveals that the Curie temperature as well as the saturation value of magnetization is gradually weakened by Sb2O3/CuO addition. The temperature dependence of resistivity shows that the transport behavior of the composites is governed by the grain boundaries. It is suggested that the Sb2O3 addition, acts as a separation layer between grains. Whereas, the introduction of CuO into the grain boundaries forms artificial conducting network and improves the carrier to transport. The maximum magnetoresistance was observed to be approximate to 60% at 10 K for x=0.03 which is larger than the largest MR value of pure La0.6Ca0.2Sr0.2MnO3 (40% at 10 K) in a 2 T magnetic field. Enhanced MR effect at a wide temperature range is consistent with the disorder-driven amplification of spin-dependent transport. (C) 2013 Elsevier Ltd and Techna Group S.r.l. All rights reserved.