M?ssbauer studies of nano phase Ce–Fe oxide composites

摘要

Chemical co-precipitation method was used to synthesize nano-structured α-Fe2O3-CeO2 composite by calcination of the goethite–cerium hydroxide precursor. It was observed that the precursor contained goethite matrix doped with cerium. Calcination of the precursor at 400°C showed the formation of nanosize hematite. M?ssbauer spectra show the presence of a paramagnetic component in the precursor but not in the samples calcined at 400°C to 800°C temperatures. Our study shows that Ce precipitated as CeO2 and stuck on the surface of hematite particles. The precipitation of Ce as CeO2 is independent of the concentration of Ce in the Ce–Fe–O composite.