THE STRUCTURE AND TRANSPORT PROPERTIES OF La0.9Sr0.1MnO3

Thin films of La0.9Sr0.1MnO3 (LSMO) were grown on SrTiO3 substrate by pulsed laser deposition technique at different temperatures and with various oxygen partial pressures. X-ray diffraction spectra confirmed that the grown films are of single phase. The influence of oxygen deficiency on the structure of these grown films has been studied. X-ray diffraction data suggested that higher oxygen content generally results in smaller out-of- plane lattice parameters and annealing in oxygen may further decrease the lattice parameters. The 2-θ value increases with oxygen pressure. Typically, the oxygen-deficient films behave like semiconductors. For films grown at the same temperature, the conductivity is enhanced if the oxygen content is increased. Those films grown in 1 mbar oxygen partial pressure show an upturn at low temperature. Resistivity is dominated by the hopping of adiabatic small polarons at high temperature.