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Estructura cristalina y microestructura de algunos óxidos La(2/3-x) Li 3xTiO3: un ejemplo del uso complementario de
Susana García-Martín1, Miguel A Alario-Franco, Helmut Ehrenberg
1Departamento de Química Inorgánica, Facultad de Ciencias Químicas, Universidad Complutense, 28040- Madrid, Spain.
Journal of the American Chemical Society
|March 18, 2004
Resumen
Los investigadores estudiaron los óxidos La(2/3-x) Li(3x) TiO3, revelando una estructura relacionada con la perovskita con octaedros inclinados de TiO6. Este trabajo refina los modelos de la estructura cristalina y explica las microestructuras complejas en estos materiales.
Área de la Ciencia:
- Química del estado sólido.
- Ciencia de los materiales ciencia de los materiales.
- La cristalografía es una técnica de cristalografía.
Sus antecedentes:
- Los óxidos de La(2/3-x) Li(3x) TiO3 son materiales complejos con aplicaciones potenciales.
- Comprender su estructura cristalina y microestructura es crucial para la predicción de propiedades.
Objetivo del estudio:
- Para dilucidar la estructura cristalina y la microestructura de los óxidos La(2/3-x) Li(3x) TiO3.
- Proponer un modelo estructural refinado que tenga en cuenta las complejidades observadas.
Principales métodos:
- Difracción de electrones de área seleccionada (SAED, por sus siglas en inglés)
- Microscopía electrónica de transmisión de alta resolución (HRTEM, por sus siglas en inglés)
- Sincrotrón en polvo de difracción de rayos X por difracción de rayos X.
Principales resultados:
- Se identificó una estructura relacionada con la perovskita con una célula unitaria diagonal (√2ap x √2ap x 2ap), que surge de la inclinación del octaedro TiO6.
- Se determinó el ordenamiento de La, Liones y vacantes, junto con los desplazamientos de Tiones.
- Se caracterizaron el tamaño / forma del dominio y los defectos extendidos como la deformación y las fluctuaciones de composición.
Conclusiones:
- El estudio proporciona un modelo estructural refinado para los óxidos La{2/3-x) Li{3x) TiO3.
- El modelo propuesto integra con éxito la compleja microestructura observada.
- La caracterización detallada de los defectos ofrece información sobre las propiedades de los materiales.
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