Surface magnetism in ZnO/Co_3O_4 mixtures
We recently reported the observation of room temperature ferromagnetism in mixtures of ZnO and Co_3O_4 despite the diamagnetic and antiferromagnetic character of these oxides, respectively. Here, we present a detailed study on the electronic structure of this material in order to account for the une...
| Autores: | , , , , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2010 |
| País: | España |
| Institución: | Universidad Complutense de Madrid (UCM) |
| Repositorio: | Docta Complutense |
| Idioma: | inglés |
| OAI Identifier: | oai:docta.ucm.es:20.500.14352/44716 |
| Acceso en línea: | https://hdl.handle.net/20.500.14352/44716 |
| Access Level: | acceso abierto |
| Palabra clave: | 538.9 Room-temperature Doped ZnO Sol-gel Ferromagnetism Oxide Física de materiales Física del estado sólido 2211 Física del Estado Sólido |
| Sumario: | We recently reported the observation of room temperature ferromagnetism in mixtures of ZnO and Co_3O_4 despite the diamagnetic and antiferromagnetic character of these oxides, respectively. Here, we present a detailed study on the electronic structure of this material in order to account for the unexpected ferromagnetism. Electrostatic interactions between both oxides lead to a dispersion of Co_3O_4 particles over the surface of ZnO larger ones. As a consequence, the reduction Co^(+3) -> Co^(2+) at the particle surface takes place as evidenced by x-ray absorption spectroscopy measurements and optical spectroscopy. This reduction allows explaining the observed ferromagnetic signal within the well established theories of magnetism in oxides. |
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