Microstructure-dependent magnetoresistance in La1−xMnO3 thin films

Abstract We have prepared thin La 1− x MnO 3 films by metal organic chemical vapour deposition. The films were grown at deposition temperature T D =700°C on various types of substrates; polycrystalline Al 2 O 3 , polycrystalline SrTiO 3 having various grain size, and single-crystalline SrTiO 3 slices. The films exhibited transition to metallic state at temperatures from 200 to 260 K, depending on the substrate. Resistivity at the transition ranged from the value of 10 Ω cm for the small grain size polycrystalline films to 100 and 300 mΩ cm for the large grain size polycrystalline and epitaxial film on the SrTiO 3 single-crystalline substrate, respectively. We discuss magnetoresistance in the La 1− x MnO 3 films in correlation with their microstructure, studied by transmission electron microscopy.