Room-temperature ferromagnetism in Co and Nb co-doped TiO{sub 2} nanoparticles

Journal Article · Fri Feb 27 00:00:00 EST 2015 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.4913539· OSTI ID:22391189

Hachisu, M.; Mori, K.; Hyodo, K.; Morimoto, S.; Yamazaki, T.; Ichiyanagi, Y. ^[1]

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1. Department of Physics, Graduate School of Engineering, Yokohama National University, 79-5 Tokiwadai, Hodogaya, Yokohama, Kanagawa 240-8501 (Japan)

Co- and Nb-doped TiO{sub 2} nanoparticles encapsulated with amorphous SiO{sub 2} were synthesized by our novel preparation method. An anatase TiO{sub 2} single-phase structure was confirmed using X-ray diffraction. The particle size could be controlled to be about 5 nm. The composition of these nanoparticles was investigated by X-ray fluorescence analysis. X-ray absorption near-edge structure spectra showed that the Ti{sup 4+} and Co{sup 2+} states were dominant in our prepared samples. A reduction in the coordination number was also confirmed. The dependence of the electrical conductivity on the frequency was measured by an LCR meter, and the carrier concentration was determined. The magnetization curves for the nanoparticles indicated ferromagnetic behavior at room temperature. We concluded that the ferromagnetism originated in oxygen vacancies around the transition metal ions.

• OSTI ID: 22391189
• Journal Information: AIP Conference Proceedings, Vol. 1649, Issue 1; Conference: IRAGO Conference 2014, Tsukuba-city, Ibaraki (Japan), 6-7 Nov 2014; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

77 NANOSCIENCE AND NANOTECHNOLOGY
COBALT COMPOUNDS
COBALT IONS
CONCENTRATION RATIO
DOPED MATERIALS
ELECTRIC CONDUCTIVITY
FERROMAGNETISM
MAGNETIZATION
NANOPARTICLES
NIOBIUM COMPOUNDS
PARTICLE SIZE
SILICON OXIDES
TEMPERATURE RANGE 0273-0400 K
TITANIUM IONS
TITANIUM OXIDES
VACANCIES
X-RAY DIFFRACTION
X-RAY FLUORESCENCE ANALYSIS