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Título:
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Cobalt (II) environment characterization in sol-gel thermochromic sensors
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Autores:
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Carmona Tejero, Noemi ;
Bouzas, V. ;
Jiménez, F. ;
Plaza, M. ;
Pérez García, Lucas ;
García, M. A. ;
Villegas, M. A. ;
LLopis, J.
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Tipo de documento:
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texto impreso
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Editorial:
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Elsevier Science S A, 2010-03-04
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Dimensiones:
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application/pdf
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Nota general:
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info:eu-repo/semantics/openAccess
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Idiomas:
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Palabras clave:
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Estado = Publicado
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Materia = Ciencias: Física: Física de materiales
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Materia = Ciencias: Física: Física del estado sólido
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Tipo = Artículo
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Resumen:
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Optical absorption and magnetic properties of silica sol-gel monoliths doped with cobalt starting from different precursors and water/1-propanol molar ratios are investigated. Structural characterization of the sol-gel by X-ray absorption near-edge structure (XANES) spectroscopy and extended X-ray absorption fine structure (EXAFS) spectroscopy corroborate, that oxidising state of cobalt is Co^(2+). Furthermore, the Co^(2+) first neighbors are O atoms displaying a temperature transition from octahedral to tetrahedral coordination. The doped monoliths show thermochromic sensor activity ranging from 10 to 50? C, which is related to the environment of Co^(2+) ions. The magnetic susceptibility also varies with Co^(2+) ions environment due to changes in the orbital contribution to the magnetic moment. Thus, we achieve a better understanding about environment of the Co^(2+) ions in the gel matrix and explain their reversible temperature behaviour in spite of the rigid state of the host matrix.
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En línea:
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https://eprints.ucm.es/45433/1/P%C3%A9rezLucas%2002%20preprint.pdf
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