Electromagnetic transport properties and magnetoresistance of La0.7Ca0.2Sr0.1MnO3-Ag composites prepared by electroless process

A series of bulk polycrystalline La0.7Ca0.2Sr0.1MnO3 (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 rho decreased with increasing plating time. We also observed Ag-added can significantly enhance the magnetoresistance (MR) near T-p, under a low applied held (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. (C) 2008 Elsevier Inc. All rights reserved.