Structural, magnetic and transport properties of the La0.7Sr0.3MnO3-ZnO nanocomposites

Abstract

La0.7Sr0.3MnO3 (LSMO)-ZnO composites with varying concentration of the ZnO have been synthesized by the sol-gel method. The effect of ZnO addition on the structural, magnetic and transport properties of the LSMO have been studied in detail. XRD data confirms the coexistence of both phases in the composites. The calculated average particle size of the composite samples was found to be in the range of 16–25nm. The magnetization measurement shows a decrease in magnetization and shift in the transition temperature towards a lower temperature with an increase in ZnO content. The electrical resistivity studies show that the resistivity increases and the metal-insulator transition temperature decreases with increase in the amount of ZnO in LSMO. The effect of ZnO on the transport behavior is explained using different conduction mechanism in different temperature regions. The magnetoresistance measurement shows the enhancement of the low field magnetoresistance and magnetic field sensitivity in the LSMO-ZnO composite samples compared to pure LSMO. The LSMO-ZnO composite sample shows 32.8% MR for an applied magnetic field of 1T at 10K.