Large magnetocaloric and magnetoresistance effects in metamagnetic Sm0.55(Sr0.5Ca0.5)0.45MnO3 manganite

The metamagnetic transition, magnetocaloric and magnetoresistance effects are investigated in polycrystalline Sm0.55(Sr0.5Ca0.5)0.45MnO3 (SSCMO) manganite. A sharp magnetization jump at Curie temperature (TC) 73.5 K with large thermal hysteresis is observed. Magnetic measurements and Arrott plots analysis indicate that the transition is first order in nature. Under a low magnetic field change of 1 T, the magnetic entropy change exhibits a peak value of −ΔSMmax(T)=4.01 J/kg K with relative cooling power (RCP) value of 44.1 J/kg in the vicinity of TC. The mechanism of charge conduction in insulator phase is polaron transport. Large negative magnetoresistance ratio with value of ~99% is obtained within a broad temperature range below metal insulator transition temperature under 1 T magnetic field. These results indicate the potential applications of SSCMO in magnetic refrigeration and spintronics devices.