Structure and impedance spectroscopy of La0.6Ca0.4Fe0.8Ni0.2O3−δ thin films grown by pulsed laser deposition

Polycrystalline samples of La0.6Ca0.4Fe0.8Ni0.2O3 (LCFN) were prepared by the liquid mix process at 600 °C. The structure of the polycrystalline powders was analyzed with X-ray powder diffraction data. The XRD patterns were indexed as the orthoferrite similar to that of PrFeO3 having a single phase orthorhombic perovskite structure (Pbnm). LCFN films have been deposited on yttria-stabilized zirconia (YSZ) single crystal and polycrystalline substrates at 700 °C by pulsed laser deposition (PLD) for application to thin film solid oxide fuel cell cathodes. The structure of the films was analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM). Both films are polycrystalline with a marked texture and present pyramidal grains in the surface with different size distribution. Electrochemical impedance spectroscopy (EIS) measurements of LCFN/YSZ single crystal/LCFN and LCFN/polycrystalline YSZ/LCFN test cells were conducted. The obtained ASR values at 850 °C for the single crystal and polycrystalline YSZ cell tests were 1.84 and 1.59 Ω cm2, respectively.