Influence of substrate temperature on structural, morphological and electrical properties of La0.6Sr0.4Co0.2Fe0.8O3 thin films for IT-SOFCs

The crack free, homogeneous, nanocrystalline La0.6Sr0.4Co0.2Fe0.8O3 thin films have been deposited on Ce0.9Gd0.1O1.95 electrolyte by the spray pyrolysis technique. The films with typically 1–2 μm thickness, get crystallized on annealing at 800 °C. In the present work, the effect of substrate temperature on microstructure, crystallization and conductivity has been systematically studied. The deposition of film at 300 °C shows higher in plane electrical conductivity of 26.6 S cm−1 with activation energy, Ea = 0.23 eV. The higher conductivity attributes to uniform, thin and dense microstructure of thin films. No interfacial reaction products between La0.6Sr0.4Co0.2Fe0.8O3 and Ce0.9Gd0.1O1.95 were detected upon annealing at 800 °C/4 h. The uniformity and porosity distribution as a function of deposition temperature clarified from Scanning Electron micrograph.