Electromagnetic transport properties and magnetoresistance of La 0.7Ca 0.2Sr 0.1MnO 3-Ag composites prepared by electroless process

A series of bulk polycrystalline La _0.7Ca _0.2Sr _0.1MnO ₃ (LCSMO)-Ag composites were prepared by electroless plating process and several kinds of physical properties have been studied systemically. According to the results of X-ray diffraction (XRD), scanning electron microscopy (SEM), and electromagnetic transport properties, we can see that Ag-added segregated at the surfaces or interfaces of LCSMO grains. The metal-insulator transition temperature ( T_P) and Curie temperature ( T_c) were almost unchanged but ρ decreased with increasing plating time. We also observed Ag-added can significantly enhance the magnetoresistance (MR) near T_P under a low applied field (3000 Oe) and the room temperature MR reached to 35% under 20 kOe, which is encouraging for practical applications. We can suggest that improved grain boundary effect by Ag-added is responsible for the enhancement.