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Transición de espín del hierro en magnesiowüstita en el manto inferior de la Tierra
Jung-Fu Lin1, Viktor V Struzhkin, Steven D Jacobsen
1Geophysical Laboratory, Carnegie Institution of Washington, 5251 Broad Branch Road NW, Washington, DC 20015, USA. j.lin@gl.ciw.edu
Nature
|July 22, 2005
Resumen
El hierro de hierro de hierro.
Área de la Ciencia:
- La geofísica es la geofísica.
- Física mineral Física de los minerales
- Ciencias de la Tierra Ciencias de la Tierra Ciencias de la Tierra
Sus antecedentes:
- El hierro es el metal de transición más abundante en el manto de la Tierra.
- Transiciones de espín electrónico inducidas por presión del manto de impacto de hierro Geoquímica y geodinámica.
- Estas transiciones ocurren en minerales clave del manto como la magnesiowüstita.
Objetivo del estudio:
- Investigar los estados de espín del hierro en magnesiowüstite bajo presión extrema.
- Determinar los efectos de las transiciones electrónicas en la elasticidad de la magnesiowüstita.
- Comprender la heterogeneidad de las ondas sísmicas en el manto más bajo de la Tierra.
Principales métodos:
- Espectroscopia de emisión de rayos X in situ.
- Difracción de rayos X in situ. difracción de rayos X in situ.
- Estudió magnesiowüstite a presiones relevantes para el manto más bajo.
Principales resultados:
- Se observó una transición electrónica de alto espín a bajo espín de hierro en magnesiowüstite.
- Esta transición causa un comportamiento de compresión anormal.
- El estado de baja rotación muestra un aumento del 35% en el módulo de volumen y un aumento del 15% en la velocidad del sonido a granel.
Conclusiones:
- La transición de espín en la magnesiowüstita explica la heterogeneidad de las ondas sísmicas en el manto más bajo.
- Los cambios de elasticidad debidos a la transición de espín deben considerarse en los modelos geofísicos y geoquímicos.
- Los modelos actuales pueden ser inexactos si no tienen en cuenta estas transiciones electrónicas.
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