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 ( k c h e m ) 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.