Presence of Room Temperature Ferromagnetism in CO2+ Doped TiO2 Nanoparticles Synthesized through Shape Transformation
| Autor: | Tamara Radetić, J. Kuljanin-Jakovljević, Zorica Konstantinović, Zoran Šaponjić, Jovan M. Nedeljković, Marija Radoičić |
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| Rok vydání: | 2009 |
| Předmět: |
Anatase
Materials science Band gap Doping Analytical chemistry Nanoparticle Physics::Optics Nanotechnology 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences Surfaces Coatings and Films Electronic Optical and Magnetic Materials Nanomaterials Condensed Matter::Materials Science General Energy Ferromagnetism Nanocrystal Physical and Theoretical Chemistry 0210 nano-technology High-resolution transmission electron microscopy |
| Zdroj: | Journal of Physical Chemistry. C |
| Popis: | New approach for synthesis of Co2+ doped TiO2 nanoparticles showing room temperature ferromagnetic behavior, through shape transformation of hydrothermally treated scrolled titania nanotubes in the presence of Co2+ ions is described. The XRD and ICP measurements demonstrated successful incorporation of 0.46 at % Co2+ ions in preserved anatase crystal structure of TiO2 nanoparticles, without presence of Co-oxide Clustering, metallic Co, or Various Co-Ti oxide species. HRTEM measurements revealed that majority of the nanoparticles have polygonal shapes with average dimension of similar to 6-10 nm. Obtained Value of 3.06 eV for band gap energy of Co2+ doped TiO2 nanoparticles explained altered optical properties of TiO2 matrix and indicates narrowing of the electronic properties in respect to the undoped anatase TiO2 nanomaterials. The Co2+ doped TiO2 nanocrystals enabled synthesis of optically transparent film that shows room temperature ferromagnetic ordering with a saturation magnetic moment of 0 25 mu B per Co atom The proposed explanation for room temperature ferromagnetic behavior is based oil the presence of critical amount of oxygen vacancies that mediate interaction between Co2+ spins trapped in the lattice Structure of titania nanoparticles with undercoordinated surface defect sites. |
| Databáze: | OpenAIRE |
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