Structural, optical and magnetic properties of Fe-doped CeO2 samples probed using X-ray photoelectron spectroscopy

• Published in: Journal of materials science. Materials in electronics 2018-06, Vol.29 (12), p.10141-10153
• Main Authors: Soni, Swati, Vats, V. S., Kumar, Sudhish, Dalela, B., Mishra, Monu, Meena, R. S., Gupta, Govind, Alvi, P. A., Dalela, S.
• Format: Article
• Language: English
• Subjects: Absorption spectra; Cerium oxides; Characterization and Evaluation of Materials; Chemical synthesis; Chemistry and Materials Science; Diamagnetism; Diffraction patterns; Displays; Doping; Electronic properties; Electronic structure; Energy gap; Ferromagnetism; Fluorite; Hysteresis loops; Lattice vacancies; Magnetic properties; Magnetism; Materials Science; Optical and Electronic Materials; Optical properties; Optoelectronics; Photoelectric emission; Polycrystals; Spectrum analysis; Spintronics; X ray photoelectron spectroscopy; X-ray diffraction
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-018-9060-x

The present study reports the effect of Fe-doping on the structural, optical, magnetic and electronic properties of polycrystalline CeO 2 (for 5 and 10% doping concentration of Fe-cation) samples synthesized by low-temperature solid-state reaction method. Rietveld refinement of the X-ray diffraction patterns establishes fluorite-type face-centred cubic structure of the Fe-doped CeO 2 samples and also confirms successful incorporation of Fe ions in the CeO 2 lattice. The UV–Vis–NIR absorption spectra displays reduce band gap energy with rising fluency of Fe-ions, which confirm red shifts in the Fe-doped CeO 2 samples. The electronic structure of the pure CeO 2 and Fe-doped CeO 2 polycrystalline samples have been investigated by X-ray photoemission spectroscopy (XPS). The XPS spectra of Ce 3d reveals the reduction of Ce 4+ to Ce 3+ states Fe-doped CeO 2 samples, which are well supported by the Fe 2p and O 1s spectra. Pure polycrystalline CeO 2 displays diamagnetic behaviour at room temperature. Interestingly, 5% Fe-doped CeO 2 sample displays S-shape hysteresis loop and establishes room temperature ferromagnetism, whereas, 10% Fe-doped CeO 2 sample shows weak ferromagnetic behaviour. A decrement is observed in the magnetization on increasing the doping concentration. The possible reason for ferromagnetism in the Fe-doped CeO 2 samples may be incorporation of oxygen vacancies, which are further discussed using F-centre exchange mechanism and double exchange interaction. These experimental findings offer potential opportunities for spintronics and optoelectronics applications by integrating them into device structures and evaluating their performance as a function of their material properties.