Synthesis and characterization of La0.8Sr0.2Ni(1−x)CrxO3 (x=0.0, 0.2, 0.4, 0.6, 0.8, 1.0) system by the combustion method

Abstract This research focuses on the synthesis and characterization of six ceramic perovskite oxides based on La 0.8 Sr 0.2 Ni (1− x ) Cr x O 3 system, with different levels of chromium modification ( x  = 0.0, 0.2, 0.4, 0.6, 0.8 and 1.0), for use as anode material in solid oxide fuel cells (SOFC). The oxides were obtained in two reaction stages, starting from corresponding nitrate salts and citric acid until formation of a solid metal complex consistent with citrate species. The solid metal organic foams were calcined at 1000 °C for 120 min under oxygen flow conditions and were characterized by infrared and ultraviolet spectroscopy (FTIR-UV), validating the proposed methodology in terms of purity and chemical composition. The characterization by X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray energy dispersive spectroscopy (EDX) confirms the obtention of a homogeneous perovskite structure in all analyzed phases. The evaluation of crystallite size by means of the Debye–Scherrer equation establishes a nanometric prevalence around 3.2–4.4 nm along main diffraction signals. The electrical characterization of materials by solid-state impedance spectroscopy allowed identifying a particular behavior depending on the microstructure of solids for potential applications in SOFC devices.