Influence of compressive strain on oxygen distribution in La0.7Ba0.3MnO3 thin films

The effects of annealing ambient on the structural and transport properties of epitaxial La0.7Ba0.3MnO3 films suffering large compressive strain on LaAlO3 substrates (LBMO/LAO) have been investigated. Independent of oxygen or argon ambient, a high temperature (900 degrees C) post-annealing process leads to a c-axis contraction, which can be attributed to the oxygen transfer from the in-plane to the out-of-plane direction. Meanwhile, the transport properties are similar with each other for both the Ar-annealed and O-2-annealed films. The comparison of the ambient annealing effects between the highly strained LBMO/LAO films and negligibly strained LBMO films on SrTiO3 substrates indicates that a large in-plane compressive strain favors decreasing oxygen deficiency in the films, especially in the ab-plane. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3573494]