Structural and Magnetic Properties of Cr- and Fe-Doped CeO<sub>2</sub> Nanoparticles Prepared by Sol-Gel Method

Abstract

A study of the structural and magnetic properties of Cr-and Fe-doped CeO2 nanoparticles produced by the sol–gel-based method was undertaken. The crystal structure and phase, morphology, and magnetic properties of the sample were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy (Raman) and physical property measurement system (PPMS). XRD and Raman studied showed that Cr-and Fe-doped did not change CeO2 original cubic fluorite crystal structure, and no ferromagnetic secondary phase was observed. SEM images showed that Cr-and Fe-doped CeO2 nanoparticles were spherical, uniform size, and good dispersion. The particle size was about 20 nm. The magnetic measurements showed that the Cr-and Fe-doped CeO2 nanoparticles presented ferromagnetic behavior at 10 and 300 K, indicating the Curie temperature was above room temperature. The magnetization diminished with the increase of the temperature. The saturation magnetization and coercivity of Fe-doped CeO2 nanoparticles were higher than that of Cr-doped CeO2 nanoparticles. Combined with the results of XRD and Raman, the ferromagnetic behavior can be attributed to the intrinsic properties of Cr-and Fe-doped CeO2 nanostructures.