Wide colossal magnetoresistance around room temperature in La0.7Ca0.3MnO3/La0.7Sr0.3MnO3 composite

The magnetoresistance (MR) of La0.7Ca0.3MnO3/La0.7Sr0.3MnO3 composite is investigated as a function of sintering temperature. Raising sintering temperature enhanced the interfacial reaction and creates interfacial phases at the boundaries of La0.7Ca0.3MnO3 and La0.7Sr0.3MnO3, as characterized by X-ray powder diffraction, scanning electron microscopy, and magnetic results. A broad MR across room temperature is observed in the composite sintered at 1300 °C, which is mainly ascribed to the combined effect of La0.7Ca0.3MnO3 and interfacial phases.