Research of magnetism in carbon –doped TiO2 thin films with different doping concentration

• Main Authors: Kuo, Che-Yu, 郭哲余
• Other Authors: Juang, Jenh-Yih
• Format: Others
• Language: en_US
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/69981745302836961304

碩士 === 國立交通大學 === 電子物理系所 === 101 === Carbon-doped titanium dioxide powders was prepared by solid state sintering at 1200 o C for 24hrs to produce TiO2 bulks with different carbon doping concentrations. The obtained TiO2 bulks were then used to deposit TiO2 thin films by pulsed laser deposition. The effects of carbon doping was investigated via a series of films obtained at various deposition conditions. The results indicate that the carbon-doped titanium dioxide evidently exhibit significant magnetization hysteresis at room temperature, indicating the realization of room-temperature ferromagnetism (RTFM). Further X-ray photoelectron spectroscopy (XPS) analysis on C-1s, O-1s, and Ti-2p electronic states showed the existence of Ti-C bonding and significant amount of oxygen vacancies. These results lend support to the p-p interaction, induced ferromagnetism in these oxides. The observed RTFM, however, did not increase with increasing doping concentration of carbon, presumably due to the excessive free carbon-induced diamagnetism.