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Nuevos productos ferroeléctricos basados en iones metálicos divalentes de aluminio
Wen Zhang1, Li-Zhuang Chen, Ren-Gen Xiong
1Ordered Matter Science Research Center, Southeast University, Nanjing 211189, PR China.
Journal of the American Chemical Society
|August 19, 2009
Resumen
Dos nuevos complejos de aluminio, el cobre (II) bis (selenato) y su versión deuterada, exhiben propiedades ferroeléctricas. Estos compuestos experimentan una transición de fase debido al ordenamiento de cationes y aniones.
Área de la Ciencia:
- Ciencia de los materiales Ciencia de los materiales.
- Química del estado sólido.
- La cristalografía es una técnica de cristalografía.
Sus antecedentes:
- Los complejos de tipo aluminio son una clase bien estudiada de sólidos cristalinos.
- La ferroelectricidad en análogos de aluminio se ha observado principalmente en sistemas de metales trivalentes.
- La exploración de ferroeléctricos basados en metales divalentes es un área activa de investigación.
Objetivo del estudio:
- Para sintetizar y caracterizar nuevos complejos de aluminio que contienen el anión selenato.
- Para investigar las propiedades ferroeléctricas de estos nuevos compuestos.
- Para determinar el mecanismo de la transición de fase paraeléctrica-ferroeléctrica.
Principales métodos:
- Difracción de rayos X de un solo cristal para determinar la estructura cristalina.
- Calorimetría de barrido diferencial (DSC) para el análisis de la transición de fase.
- Mediciones dieléctricas para confirmar el comportamiento ferroeléctrico.
Principales resultados:
- Se sintetizaron con éxito dos nuevos complejos de tipo aluminio, (H(2) dbco) Cu((H(2) O) ((6) (((SeO(4)) ((2) y su análogo deuterado.
- Ambos compuestos exhiben ferroelectricidad con una transición de fase que ocurre alrededor de -140 a -138 °C.
- La transición de fase se atribuye a los fenómenos de orden-desorden que involucran al catión 1,4-diazoniabiciclo[2.2.2]octano y el anión selenato.
Conclusiones:
- Estos son los primeros reportes de ferroeléctricos basados en análogos de aluminio de aniones metálicos divalentes.
- Los hallazgos amplían el alcance de los materiales ferroeléctricos conocidos y proporcionan información sobre las relaciones estructura-propiedad en compuestos de tipo aluminio.
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