Effect of the substrate orientation on the transport properties of La0.67Sr0.33MnO3 epitaxial films

The transport properties of La0.67Sr0.33MnO3 (LSMO) epitaxial films on diff erently orientated LaAlO3 substrates have been studied. The as-deposited fi lms with different orientation exhibit different transport behaviours. The resistivity of the films on the (100) and (110) substrates undergoes a meta l-insulator transition while the resistivity of the film on the (111) subst rate is insulator-like. This is attributed to the discrepancy of oxygen def iciency in the samples which is influenced by the lattice mismatch between the film and the substrate. After being annealed at 700 degrees C in l-atm flowing pure oxygen for half an hour, all films have the same resistivity b ehaviour as the bulk LSMO, which may be important for future applications.