Synthesis, characterization and electrical properties of La0.7Sr0.3Co0.2Fe0.8O3/Gd–CeO2 thin films (≤500 nm)

Abstract

A simple route toward the synthesis of mesostructured composite La_0.7Sr_0.3Co_0.2Fe_0.8O₃x/yGd–CeO₂ (LSCFx/yGDC) (with x and y representing the volumetric% of LSCF and GDC in the composite films) thin films exhibiting both high electrical conductivities and optimized bicontinuous pore-solid network is reported. Because of the size of the pore wall, the mesostructured composite film is crystalline with particle size in the nanometer range even after a heat-treatment at 700 °C in air. Crystallization of the film was studied by in situ impedance spectroscopy. This technique allows us to define the heat-treatment, the LSCF content in the composite film and the thickness of the film to achieve good electrical conductivity. The highest electrical conductivity of 250 S cm⁻¹ was found for the pure, mesoporous LSCF film at 700 °C.