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Manganese Oxide Nanoparticle Synthesis by Thermal Decomposition of Manganese(II) Acetylacetonate
Published on: June 18, 2020
Control oxidativo y reductor topotáctico de las estructuras y propiedades de los oxicalcogenuros de manganeso en
Geoffrey Hyett1, Nicolas Barrier, Simon J Clarke
1Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory, South Parks Road, Oxford, OX1 3QR, UK.
Journal of the American Chemical Society
|August 21, 2007
Resumen
La modificación topotáctica de los oxicalcogenuros en capas permite controlar su composición y propiedades magnéticas. La oxidación mejora el ordenamiento antiferromagnético, mientras que la reducción lo interrumpe, lo que lleva al desorden y la frustración.
Área de la Ciencia:
- Ciencia de los materiales Ciencia de los materiales.
- Química del estado sólido.
- El magnetismo es el magnetismo.
Sus antecedentes:
- Los oxicalcogenuros en capas Sr4Mn3O7.5Cu2Ch2 (Ch=S, Se) se caracterizan por la alternancia de losas de óxido de manganeso de estroncio tipo perovskita y capas de calogenuro de cobre tipo anti-fluorito.
- Estos compuestos son intrínsecamente deficientes en óxido en la capa central de las losas de perovskita, ofreciendo sitios únicos para la modificación topotáctica.
Objetivo del estudio:
- Para investigar la modificación topotáctica de Sr4Mn3O7.5Cu2Ch2 a través de la oxidación y la reducción.
- Comprender el impacto de estas modificaciones en la composición, estructura y propiedades magnéticas de los compuestos.
Principales métodos:
- Oxidación topotáctica a través de la fluoración.
- Reducción topotáctica a través de la desintercalación del oxígeno.
- Caracterización de las propiedades estructurales y magnéticas.
Principales resultados:
- La fluoración aumentó la temperatura de ordenamiento antiferromagnético y el tamaño del momento ordenado.
- La reducción destruyó el orden magnético de largo alcance mediante la introducción de desorden químico.
- Los momentos magnéticos de manganeso en las capas externas de perovskita mostraron un ordenamiento antiferromagnético, mientras que las capas centrales exhibieron un comportamiento similar al de un vidrio giratorio.
Conclusiones:
- La modificación topotáctica ofrece una ruta para ajustar el comportamiento magnético de los oxicalcogenuros en capas.
- La oxidación mejora el orden magnético, mientras que la reducción conduce al desorden y la frustración de las interacciones magnéticas.
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