Large room temperature magnetoresistance in La0.9Sr0.1MnO3 thin films

Epitaxial La0.9Sr0.1MnO3 thin films were crystallized using post-annealing after deposited at room temperature, and the effect of sputtering pressure on the structural, magnetic and electrical properties was investigated. It is interesting to note that the out-of-plane lattice parameter decreases with decreasing sputtering pressure, which is attributed to the reduction of Mn3+/Mn4+ ratio. Differing from the corresponding bulk material, all the films show metal-insulator (MI) transition with a significantly enhanced Curie temperature (TC). And the film deposited at 1.0 Pa shows the maximum TMI and TC resulted from the strongest double exchange interaction. Most significantly, the largest magnetoresistance around room temperature (−53% at 3 T and 295 K) is also observed in this film, showing great potential in application.