Enhancement of electronic transport and magnetoresistance of Al2O3-impregnated (La0.5Pr0.2)Sr0.3MnO3 thin films

We have used a non-magnetic Al2O3 barrier, impregnated in (La0.5Pr0.2)Sr0.3MnO3 (LPSMO) thin film layers, to obtain large magnetoresistance (MR) in the vicinity of room temperature. In the magnetic field of 1T, the LPSMO/Al2O3/LPSMO heterostructure exhibits an MR of ~35% at its insulator-to-metal transition temperature (TIM) of ~220 K vis-a-vis an MR of ~8% in the pristine LPSMO film at its TIM of 298 K. This enhanced MR, coupled with a 2- to 3-fold increase in the temperature coefficient of resistance and the field coefficient of resistance in the heterostructure compared to that in the LPSMO films, demonstrates the efficiency of this technique in engineering those physical properties of manganites which have potential bearing on the realization of their technological applications.