Electrical conductivity of epitaxial La0.6Sr0.4Co0.2Fe0.8O3−δ thin films grown by pulsed laser deposition

Epitaxial La0.6Sr0.4Co0.2Fe0.8O3−δ (LSCF) thin films have been grown successfully on single crystal LaAlO3 substrate by pulsed laser deposition (PLD). AFM micrographs have shown a rms roughness of 5Å for the 550 °C deposited films. The films further exhibited electrical conductivities of as high as 2.3 × 103 S cm−1 at 600 °C, with an activation energy of 0.09 eV. The surface exchange coefficient (kchemkchem) of the epitaxial LSCF thin film, determined by electrical conductivity relaxation (ECR) technique, increased with the increasing temperature, and reached a value of ∼5.1 × 10−6 S cm−1 at temperatures above 620 °C.