Porous and dense perovskite films

La0.5Sr0.5CoO3 (LSCO) and La 0.67Ca0.33MnO3 (LCMO) films were prepared by sol-gel techniques and their structural and transport properties investigated. Films were spin-coated onto (001) LaAlO3 (LAO), (001) SrTiO 3 (STO), Pt/TiO2/SiO2/Si, and Al 2O3 substrates, and heated to 800C. The structural properties were investigated using X-ray diffraction, scanning and transmission electron microscopy (SEM and TEM). SEM studies showed that the films were crack-free and adhered well to the substrates. No preferential orientation of the perovskite films was observed on Si- or Pt/TiO2/SiO 2/Si-substrates, but films deposited on LAO and STO showed good alignment with the substrate. Transport measurements of epitaxial LCMO films show maximum temperature coefficient of resistivity (TCR) of 6.1% K-1 at 241 K and colossal magnetoresistance (CMR) of 32% at 246 K. The conductivity LSCO polycrystalline film was 1.7 mcm, while a epitaxial film had a conductivity of around 1.9 mcm.