Effect of Post-Deposition Thermal Treatments on the Structure and Properties of Metal Oxide Thin Films

Metal Oxide thin films belonging to the ABO₃ perovskite family of materials have many important applications including use in renewable energy technologies. Material properties needed for these applications can be optimized by varying the chemistry of these samples, oxygen content being an especially important parameter. Oxygen content in thin films can be varied using post-deposition thermal treatment ( annealing) in different ambients. I will present our research results on the effect of post-deposition thermal processing on the properties of thin films of the perovskite oxide materials La_0.67Ca_0.33MnO₃ and SrTiO₃ in different oxidizing and reducing gas ambients. Properties of interest include electrical resistivity, crystal structure and surface morphology. Electrical resistivity is measured by DC four probe method, crystal structure is determined by x-ray diffraction and surface morphology is analyzed using atomic force microscopy. Our initial studies indicate that annealing in an oxygen rich environment results in a shortening of the c-axis lattice parameter of La_0.67Ca_0.33MnO₃ thin films.