Room-temperature ferromagnetism in carbon- and nitrogen-doped rutile TiO sub(2)

• Published in: Applied physics. A, Materials science & processing Vol. 118; no. 2; pp. 725 - 731
• Main Authors: Wang, Jia-Bin, Wu, Kuei-Ching, Mi, Jyun-Wei, Luo, Chih-Wei, Wu, Kaung-Hsiung, Uen, Tzeng-Ming, Lin, Jiunn-Yuan, Juang, Jenh-Yih, Liu, Shiu-Jen
• Format: Journal Article
• Language: English
• Published: 01.02.2015
• Subjects: Band theory; Density functional theory; Ferromagnetism; Mathematical analysis; Rutile; Titanium; Titanium dioxide; X-rays
• ISSN: 0947-8396; 1432-0630
• DOI: 10.1007/s00339-014-8788-2

Marked room-temperature ferromagnetism (RTFM) was obtained in carbon- and nitrogen-doped rutile \(\hbox {TiO}_2\) powders. X-ray photoelectron spectroscopy measurements revealed the co-existence of considerable densities of states near the Fermi level ( \(E_{\rm F}\) ) and oxygen vacancies primarily induced by C- and N-doping. Density functional theory calculations showed that the local moments responsible for the observed RTFM in N-doped \(\hbox {TiO}_2\) were primarily attributed to the partially populated, spin-polarized Ti \(3d\) band. In addition to the unfilled Ti \(3d\) band, the spin splitting in C \(2p\) states near \(E_{\rm F}\) in C-doped \(\hbox {TiO}_2\) , which may be induced by the \(p-p\) interaction between the C impurities and neighboring oxygen ions, results in Stoner band-splitting-type ferromagnetism.