Enhanced room temperature magnetoresistance in La0.7 Ca0.2 Sr0.1 MnO3/Ag composites

The effect of added Ag on the electro-magnetic properties and enhanced room temperature magnetoresistance in (La0.7Ca0.2Sr0.1MnO3)1-x/Agx composites has been studied systematically. According to the results of x-ray diffraction, scanning electron microscopy and magnetic measurement, we can suggest that Ag segregates at the grain surface of La0.7Ca0.2Sr0.1MnO3. The results of electronic measurements show that the intrinsic insulator/metal transition temperature (TP) does not change, which is in accordance with the results for the Curie temperature (TC). It is very interesting to note that the magnetoresistance at room temperature is enhanced, which is encouraging for potential applications. These phenomena can be explained by considering that Ag, which segregated at the grain boundaries or surfaces, does not change the intrinsic structure of La0.7Ca0.2Sr0.1MnO3 and lead to a modification of grain boundaries