The Electronic Property and The Local Structure of Room-Temperature Ferromagnetic Nanocrystalline Sm-doped CeO2

• Main Authors: Ren-Jie Chen, 陳人傑
• Other Authors: Shih-Yun Chen
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/78078962259411871851

碩士 === 國立臺灣科技大學 === 材料科學與工程系 === 100 === The Sm-doped CeO2 nanoparticles were prepared by the precipitation method. The crystal structure, phase and room temperature magnetism of the nanoparticles were investigated by X-ray Diffraction (XRD), X-ray Absorption Spectroscopy(XAS), Magnetic Circular Dichroism (MCD) and Superconducting Quantum Interference Device (SQUID). The change of coordination number and bond length of different elements inside the nanoparticles were analyzed by the Extended X-ray Absorption Fine Structure (EXAFS) spectra. Our results presented that the valence of Sm is tri-valence. In addition, the formation of Sm2O3 was observed. According to the XAS analysis results, Sm2O3 clusters tend to locate at the surface of CeO2 particles. The existence of Sm2O3 also lead to the formation of oxygen vacancy at the interface between Sm2O3 and CeO2, and then increase the concentration of Ce3+. Above differences including the concentration of Ce3+ as well as the distribution result in the enhancement of Ms.