Giant enhancement of room-temperature magnetoresistance in La0.67Sr0.33MnO3∕Nd0.67Sr0.33MnO3 multilayers

Abstract

The metal-insulator transition temperature in colossal magnetoresistance manganites has been altered and brought close to the room temperature by preparing La0.67Sr0.33MnO3 (LSMO)∕Nd0.67Sr0.33MnO3 (NSMO) multilayers with ultrathin individual layers of LSMO and NSMO. The LSMO/NSMO multilayers with ultrathin individual layers of thickness of about 10 Å exhibits 150% magnetoresistance at 270 K whereas LSMO/NSMO multilayers with moderate individual layer thickness of about 40 Å each exhibits a mere 15% magnetoresistance at the same temperature. We have shown that the reduction in thickness of the individual layers leads to increased spin fluctuation which results in the enhancement of magnetoresistance.