Effect of Post-deposition Thermal Treatment on the Structural and Electrical Properties of Oxygen Deficient Perovskite Metal Oxide Thin Films

Thin films of perovskite metal oxides such as SrTiO3 (STO), La_0.67Ca _0.33MnO₃ (LCMO) and CaMnO3 (CMO) exhibit many interesting electronic properties that are useful for technological applications. These properties are highly sensitive to the oxygen stoichiometry in the thin films, which can be varied by subjecting the thin films to heat treatment (annealing) after the film is deposited. We will discuss the results of our experiments to study changes in the lattice constants and electrical resistivity induced by post-deposition annealing in various gas ambients and in vacuum. We will also present the effects of annealing in the presence of a fluorine-containing polymer with the goal of incorporating fluorine in the film crystal structure. Thin films in this study are grown using pulsed laser deposition, lattice constants are determined using 4-circle x-ray diffraction and resistivity is measured using a 4-probe VanDerpauw technique.