Preparation of La1−x Sr x CoO3 Oxide Electrode Material and its Influence on the Structure and Dielectric Performance of the Supported Ba1−x Sr x TiO3 Thin Films

Abstract

Using the sol–gel method, La1−x Sr x CoO3 (LSCO) electrode films were first fabricated on the Si (100) substrates, followed by the growth of Ba1−x Sr x TiO3 (BST) thin films on the LSCO electrode film. The crystal structure and surface morphology of these films were characterized by XRD and SEM. The effects of Sr-doping and annealing temperature on the structure and electric resistivity of the LSCO films and the dielectric properties of the BST films were studied. Results show that the La0.5Sr0.5CoO3 electrode annealed at 750 °C has the lowest electric resistivity, 1.1 × 10−3Ω cm. The relative permittivity of the La0.5Sr0.5CoO3-supported BST films first increases and then decreases with Sr-doping. The relative permittivity of the BST film decreases while the dielectric loss increases with frequency. Among the studied BST films, Ba0.5Sr0.5TiO3 has the largest relative permittivity and the smallest dielectric loss (95 and 0.1, respectively) when the frequency is 1 kHz.