Synthesis and characterization of perovskite oxides lafe_1-xcu_xo₃ (0 ≤ x ≤ 0.4) obtained by sol-gel method

Abstract

LaFe_1-xCu_xO₃ (where x ranged from 0 to 0.4) powders are successfully synthesized by the solgel method employing metal nitrate salts as cations precursors and methanol as solvent. Thermogravimetric and differential thermal analysis (TGA/DTA) results exhibit that decomposition of the precursor to the oxide completed at about 750°C. XRD patterns exhibit that the materials belong to a cubic system. All samples show two IR active vibrational modes, one at 560 cm^-1 assigned to Fe-O stretching vibration and another one at 1385 cm-1 assigned to the stretching of metal carbonates. SEM images of the samples show that the particle size is from 63 to 158 nm and the specific surface areas are relatively low. The electrochemical measurements exhibit that the catalytic activity is influenced by copper doping. The highest electrode performance is achieved with the oxide LaFe_0.7Cu_0.3O₃.

Keywords: perovskite oxide, sol-gel, thermogravimetric analysis, powder diffraction,
electrochemical properties.