LaSrCoFeO and Fe2O3/LaSrCoFeO Powders: Synthesis and Characterization

This work focuses on a La 0.6 Sr 0.4 Co 0.8 Fe 0.2 O 3- δ (LaSrCoFeO) perovskite and Fe 2 O 3 /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 La 2 O 3, Co 3 O 4, and La (2- x ) Sr x CoO 4 are also present. Strontium is surface segregated as SrCO 3 and SrO. Nanocomposite Fe 2 O 3 /LaSrCoFeO powder samples (Fe 2 O 3 /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.