Sol-gel synthesis and characterization of SrFeCo_0.5O_3.25-δ powder

SrFeCo_0.5O_3.25-δ powder was synthesized by a sol-gel processing from metal alkoxides. The powder synthesized was characterized by X-ray diffraction, scanning electron microscopy (SEM), BET surface area measurements, particle size analysis, and thermogravimetric analysis (TGA). The synthesized oxide consisted of three phases: a main perovskite phase with an amount of a perovskite-related layered phase and a trace spinel phase. The powder calcined at 850°C in air for 4 h exhibited a uniform rod-shaped morphology with a particle size of about 300 nm and a surface area of 2.1 m²/g. The average agglomerate size was about 3 μm. TGA data showed that the powder was of larger oxygen nonstoichiometry at high temperature in air. Experimental results demonstrate that sol-gel processing is a very effective technique for synthesizing submicron SrFeCo_0.5O_3.25-δ powders.