Room-temperature ferromagnetism in the mixtures of the TiO₂ and Co₃O₄ powders
We report here the observation of ferromagnetism (FM) at 300 K in mixtures of TiO₂ and Co₃O₄ powders despite the antiferromagnetic and diamagnetic characters of both oxides, respectively. The ferromagnetic behavior is found in the early stages of reaction and only for TiO₂ in anatase structure; no F...
| Autores: | , , , , , |
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| Formato: | artículo |
| Fecha de publicación: | 2009 |
| País: | España |
| Recursos: | Universidad Complutense de Madrid (UCM) |
| Repositorio: | Docta Complutense |
| Idioma: | inglés |
| OAI Identifier: | oai:docta.ucm.es:20.500.14352/42777 |
| Acesso em linha: | https://hdl.handle.net/20.500.14352/42777 |
| Access Level: | acceso abierto |
| Palavra-chave: | 538.9 Magnetic semiconductors Oxides ZnO Física de materiales Física del estado sólido 2211 Física del Estado Sólido |
| Resumo: | We report here the observation of ferromagnetism (FM) at 300 K in mixtures of TiO₂ and Co₃O₄ powders despite the antiferromagnetic and diamagnetic characters of both oxides, respectively. The ferromagnetic behavior is found in the early stages of reaction and only for TiO₂ in anatase structure; no FM is found for identical samples prepared with rutile-TiO². Optical spectroscopy and x-ray absorption spectra confirm a surface reduction of octahedral Co^(+3) -> Co^(+2) in the mixtures which is in the origin of the observed magnetism. |
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