Metal-Organic Deposition of Epitaxial Lasub0.7/subSrsub0.3/subCoOsub3/subThin Films on LaAlOsub3/subSubstrates

摘要

La0.7Sr0.3CoO3 (LSCO) thin films were epitaxially grown on (001)-single crystalline LaAlO3 substrates by metal organic deposition. The evolution of the crystallinity of the films having various thicknesses and obtained at various annealing temperatures is investigated using Raman spectroscopy. The Raman mode associated to the Jahn-Teller distortions in the LSCO films is found to be dependent on the annealing temperature and sensitive to the strain state evolution with film thickness. The microstructure and morphology of the obtained films were investigated using transmission electron microscopy observations on cross-sections and atomic force microscopy. The obtained films are characterized by nanocrystalline morphology, with an average roughness around 5 nm. By increasing the annealing temperature to 1000℃ and the film thickness to 100 nm, the electrical resistivity was decreased by several orders of magnitude. The film resistivity reaches approximately 2.7 × 10–4 Ω•cm in a wide interval of temperature of 77 - 320 K, making this material a promising candidate for a variety of applications.