LaSrCoFeO and Fe2O3/LaSrCoFeO powders:: Synthesis and characterization

This work focuses on a La0.6Sr0.4Co0.8Fe0.2O3-delta (LaSrCoFeO) perovskite and Fe2O3/LaSrCoFeO nanocomposite powders; the samples are characterized by means of X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), extended X-ray absorption fine structure (EXAFS), diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy, scanning electronmicroscopy (SEM), and thermal analysis (TA) and inductively coupled plasma-atomic emission spectroscopy (ICP-AES). The nanosized LaSrCoFeO perovskite is obtained by Pechini method and is treated at increasing temperature. The LaSrCoFeO perovskite phase forms at T >= 1173 K; at this temperature, traces of La2O3, Co3O4, and La(2-x)SrxCoO4 are also present. Strontium is surface segregated as SrCO3 and SrO. Nanocomposite Fe2O3/LaSrCoFeO powder samples (Fe2O3/LaSrCoFeO = 1:9 and 1:1 wt) are obtained by wet impregnation. The iron oxide deposition damages the perovskite structure because of the diffusion of iron inside the perovskite; this is particularly evident from SEM images.