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Temperatura ambiente Ordenado magnéticamente corindón polar GaFeO3 Display de acoplamiento magnetoeléctrico
Hongjun Niu1, Michael J Pitcher1, Alex J Corkett1
1Department of Chemistry, University of Liverpool , Crown Street, Liverpool L69 7ZD, United Kingdom.
Journal of the American Chemical Society
|December 27, 2016
Resumen
Los investigadores sintetizaron un nuevo material multiferroico, el óxido de hierro de galio (GaFeO3), con una estructura de corindón polar. Este material exhibe un ferromagnetismo débil a temperatura ambiente y acoplamiento magnetoeléctrico, allanando el camino para nuevos dispositivos multiferroicos.
Área de la Ciencia:
- Ciencias de los materiales
- Física del estado sólido
- La cristalografía
Sus antecedentes:
- Las estructuras de corindón polar ofrecen potencial para materiales multiferroicos a temperatura ambiente.
- Combinar el ordenamiento de cationes polares con el ordenamiento magnético es clave para los multiferroicos.
Objetivo del estudio:
- Para sintetizar y caracterizar un óxido de hierro de gallio de corindón polar (GaFeO3).
- Para investigar el origen de su polaridad y propiedades magnéticas.
- Para demostrar el acoplamiento magnetoeléctrico para aplicaciones potenciales del dispositivo.
Principales métodos:
- La vía de síntesis de alta presión y alta temperatura.
- Difracción de neutrones, rayos X y electrones para el análisis estructural.
- Difracción de neutrones in situ para observar la formación de fase.
- Cálculos de la Teoría Funcional de Densidad (DFT) para el comportamiento de ordenamiento.
- Mediciones de la magnetización y del acoplamiento magnetoeléctrico.
Principales resultados:
- Se ha sintetizado con éxito el corindón polar GaFeO3.
- Se ha confirmado que la polaridad proviene del ordenamiento parcial de cationes de tipo LiNbO3.
- Se observó un ordenamiento magnético similar al Fe2O3, que persiste hasta 408 K.
- Se ha demostrado un coeficiente de acoplamiento magnetoeléctrico lineal de 0,057 ps/m.
Conclusiones:
- El corindón polar GaFeO3 es un material multiferroico prometedor a temperatura ambiente.
- El ordenamiento de cationes es crucial para lograr la polaridad y está influenciado por la entropía de configuración.
- El acoplamiento magnetoeléctrico demostrado es un requisito previo para las aplicaciones de dispositivos multiferroicos/magnetoeléctricos.
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