New properties of Fe3O4@SnO2 core shell nanoparticles following interface charge/spin transfer
| Autor: | Cristian Leostean, Marin Senila, Adriana Florina Popa, Ovidiu Pana, Dana Toloman, S. Gutoiu, Sergiu Macavei, Maria Stefan |
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| Rok vydání: | 2018 |
| Předmět: |
Nanocomposite
Photoluminescence Materials science Magnetic moment Band gap General Physics and Astronomy Nanoparticle Nanotechnology 02 engineering and technology Surfaces and Interfaces General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences 0104 chemical sciences Surfaces Coatings and Films Ferromagnetism Chemical engineering 0210 nano-technology High-resolution transmission electron microscopy Superparamagnetism |
| Zdroj: | Applied Surface Science. 427:192-201 |
| ISSN: | 0169-4332 |
| Popis: | The synthesis and properties of Fe3O4@SnO2 core-shell nanoparticles are reported in the present paper. To form Fe3O4@SnO2 nanocomposites (FeSn-Ox), the magnetite (Fe3O4) nanoparticles were covered with SnO2 semiconductor through the use of the seeding method followed by a thermal treatment. XRD studies reveal that the synthesized composite nanoparticles contain mainly Fe3O4 and SnO2 in different proportions depending on the preparation conditions. The composition of nanoparticles and their core-shell architecture were evidenced by XPS and confirmed by Fourier analysis of HRTEM images. Magnetic studies also indicated that FeSn-Ox samples exhibit superparamagnetic behavior at room temperature. It was found that the SnO2 shell nanocrystals contain ordered magnetic moments formed through a charge/spin transfer process across the interface (carrier-mediated ferromagnetism). The analysis of UV–vis and photoluminescence (PL) spectra of FeSn-Ox composites shows position modifications of SnO2 impurity band gap levels in accordance with the charge/spin transfer between Fe3O4 and SnO2 outer shell. |
| Databáze: | OpenAIRE |
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