Room-temperature ferromagnetism in Ni2+ doped TiO2 nanocrystals synthesized from nanotubular precursors
| Autor: | Jovan M. Nedeljković, Alberto Pomar, Mila Vranješ, J. Kuljanin Jakovljević, Zoran Šaponjić, Milovan Stoiljković, Zorica Konstantinović |
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| Rok vydání: | 2014 |
| Předmět: |
Anatase
Materials science Nanotechnology 02 engineering and technology 010402 general chemistry 01 natural sciences Materials Chemistry Hydrothermal synthesis Transmission electron microscopyTEM Dopant Oxide materials Mechanical Engineering Doping Metals and Alloys Nanostructured materials Magnetic measurements 021001 nanoscience & nanotechnology 0104 chemical sciences X-ray diffraction Chemical engineering Ferromagnetism Mechanics of Materials Transmission electron microscopy X-ray crystallography Selected area diffraction 0210 nano-technology |
| Zdroj: | Journal of Alloys and Compounds |
| Popis: | Hydrothermal synthetic route for synthesis of Ni2+ doped TiO2 nanocrystals showing room temperature ferromagnetism, using dispersion of titania nanotubes in the presence of Ni2+ ions at different pHs as precursors, is reported. Morphologies of tubular precursors and Ni2+ doped TiO2 nanocrystals were characterized by transmission electron microscopy. Titania nanotubes have outer diameter of about 10 nm while the length varies widely even reaching few hundred nanometers. Ni2+ doped TiO2 nanoparticles synthesized at pH 3 have polygonal shape and dimension of about 20 nm. Transmission electron microscopy analysis revealed presence of mixed shapes (polygonal and rod like) in the sample of Ni2+ doped TiO2 nanoparticles synthesized at pH 5. X-ray diffraction analysis of resultant powder and selected area electron diffraction pattern confirmed the anatase crystal phase of Ni2+ doped TiO2 nanoparticles independently of dopant concentrations (0.09, 0.25, 0.86, 1.48 and 1.80 at%), followed by slight changes of their microstructural parameters. Reflection spectra of Ni2+ doped TiO2 nanoparticles revealed their altered optical properties in comparison to undoped TiO2 nanoparticles. Room temperature ferromagnetic ordering with saturation magnetic moment in the range of 10(-3)-5 x 10(-2) mu B per Ni atom was observed for all measured films made of Ni2+ doped TiO2 nanoparticles. (C) 2013 Elsevier B. V. All rights reserved. |
| Databáze: | OpenAIRE |
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