Phase composition and magnetic properties of niobium-iron codoped TiO{sub 2} nanoparticles synthesized in Ar/O{sub 2} radio-frequency thermal plasma

Journal Article · Thu Sep 15 00:00:00 EDT 2011 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2011.07.025· OSTI ID:21580248

Chenning, Zhang ^[1]; Ikeda, Masashi ^[1]; Isobe, Masaaki ^[2]; Uchikoshi, Tetsuo; Li, Ji-Guang ^[1]; Watanabe, Takayuki ^[3]; Ishigaki, Takamasa ^[4]

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1. Materials Processing Unit, National Institute for Materials Science, Tsukuba, Ibaraki 305-0047 (Japan)
2. Superconducting Properties Unit, National Institute for Materials Science, Tsukuba, Ibaraki 305-0044 (Japan)
3. Department of Environmental Chemistry and Engineering, Tokyo Institute of Technology, Yokohama, Kanagawa, 226-8502 (Japan)
4. Department of Chemical Science and Technology, Hosei University, Koganei, Tokyo 184-8584 (Japan)

Nanoparticles of Nb{sup 5+}-Fe{sup 3+} codoped TiO{sub 2} with various Nb{sup 5+} concentrations (Nb/(Ti+Fe+Nb)=0-10.0 at%) and Fe{sup 3+} (Fe/(Ti+Fe+Nb)=0-2.0 at%) were synthesized using Ar/O{sub 2} thermal plasma. Dopant content, chemical valence, phase identification, morphology and magnetic properties were determined using several characterization techniques, including inductively coupled plasma-optical emission spectrometer, X-ray photoelectron spectroscopy, X-ray diffraction, UV-vis diffuse reflectance spectrometer, field-emission scanning electron microscopy, transmission electron microscopy and SQUID commercial instrument. The XRD revealed that all the plasma-synthesized powders were exclusively composed of anatase as major phase and rutile. The rutile weight fraction was increased by the substitution of Fe{sup 3+} for Ti{sup 4+} whereas it was reduced by the Nb{sup 5+} doping. The plasma-synthesized Nb{sup 5+}-Fe{sup 3+} codoped TiO{sub 2} powders had intrinsic magnetic properties of strongly paramagnetic and feebly ferromagnetic at room temperature. The ferromagnetic properties gradually deteriorated as the Fe{sup 3+} concentration was decreased, suggesting that the ferromagnetism was predominated by the phase composition as a carrier-mediated exchange. - Graphical Abstract: Spherical nanoparticles of Nb{sup 5+}-Fe{sup 3+} codoped TiO{sub 2} were synthesized using Ar/O{sub 2} thermal plasma. The plasma-synthesized powders were composed of anatase as major phase and rutile. Rutile weight fraction was increased by Fe{sup 3+} addition but was reduced by Nb{sup 5+} doping. Strongly paramagnetic and feebly ferromagnetic properties are of intrinsic nature. Ferromagnetic properties gradually deteriorated as Fe{sup 3+} concentration was increased. Highlights: > Nanoparticles of Nb{sup 5+}-Fe{sup 3+} codoped TiO{sub 2} were synthesized using Ar/O{sub 2} thermal plasma. > The plasma-synthesized powders were composed of anatase as major phase and rutile. > Rutile weight fraction was increased by Fe{sup 3+} addition but was reduced by Nb{sup 5+} doping. > Strongly paramagnetic and feebly ferromagnetic properties are of intrinsic nature. > Ferromagnetic properties gradually deteriorated as Fe{sup 3+} concentration was increased.

• OSTI ID: 21580248
• Journal Information: Journal of Solid State Chemistry, Vol. 184, Issue 9; Other Information: DOI: 10.1016/j.jssc.2011.07.025; PII: S0022-4596(11)00403-8; Copyright (c) 2011 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
FIELD EMISSION
IRON IONS
MAGNETIC PROPERTIES
NANOSTRUCTURES
NIOBIUM
NIOBIUM IONS
PARAMAGNETISM
PARTICLES
PLASMA
RADIOWAVE RADIATION
RUTILE
SCANNING ELECTRON MICROSCOPY
SQUID DEVICES
TITANIUM OXIDES
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION
X-RAY PHOTOELECTRON SPECTROSCOPY
CHALCOGENIDES
CHARGED PARTICLES
COHERENT SCATTERING
DIFFRACTION
ELECTROMAGNETIC RADIATION
ELECTRON MICROSCOPY
ELECTRON SPECTROSCOPY
ELECTRONIC EQUIPMENT
ELEMENTS
EMISSION
EQUIPMENT
FLUXMETERS
IONS
MAGNETISM
MATERIALS
MEASURING INSTRUMENTS
METALS
MICROSCOPY
MICROWAVE EQUIPMENT
MINERALS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PHOTOELECTRON SPECTROSCOPY
PHYSICAL PROPERTIES
RADIATIONS
RADIOACTIVE MATERIALS
RADIOACTIVE MINERALS
REFRACTORY METALS
SCATTERING
SPECTROSCOPY
SUPERCONDUCTING DEVICES
TITANIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS