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Caracterización XMCD del estado ferromagnético de Yb14MnSb11 por medio de las ondas magnéticas
Aaron P Holm1, Susan M Kauzlarich, Simon A Morton
1Department of Chemistry, University of California, One Shields Avenue, Davis, California 95616, USA.
Journal of the American Chemical Society
|August 15, 2002
Resumen
El dicroísmo circular magnético de rayos X revela que el manganeso (Mn) tiene un momento de 5 microB en Yb14MnSb11. Esto es parcialmente anulado por un momento opuesto en la jaula de antimonio (Sb) circundante, lo que explica la magnetización masiva.
Área de la Ciencia:
- Física de la materia condensada Física de la materia condensada Física de la materia condensada Física de la materia condensada Física de la materia condensada
- Ciencia de los materiales ciencia de los materiales.
- El magnetismo es el magnetismo.
Sus antecedentes:
- Yb14MnSb11 es un compuesto intermetálico isostructural con Ca14AlSb11.
- Los iones de manganeso ocupan el sitio del aluminio dentro de las unidades aniónicas tetraédricas discretas AlSb4(9-).
- Comprender las propiedades magnéticas de tales compuestos es crucial para las aplicaciones potenciales.
Objetivo del estudio:
- Para determinar experimentalmente el momento magnético del manganeso en Yb14MnSb11.
- Para investigar la interacción magnética entre el manganeso y la jaula de antimonio circundante.
- Para conciliar las mediciones de magnetización a granel con los momentos magnéticos locales.
Principales métodos:
- Espectroscopia de dicroísmo circular magnético de rayos X (XMCD) en los bordes Mn L23, Sb M45 y Yb N45.
- Mediciones de la magnetización a granel.
- Comparación con modelos teóricos para iones magnéticos.
Principales resultados:
- XMCD confirma un momento magnético local de aproximadamente 5 microB en los iones Mn.
- Una débil señal XMCD en el borde Sb M45 indica un momento magnético opuesto en la jaula Sb4.
- El borde de Yb N45 no muestra dicroísmo magnético, lo que sugiere que no hay un momento local significativo en Yb.
- Los espectros de Mn se alinean bien con los modelos teóricos para una configuración de Mn2+.
- La magnetización masiva se explica por un momento Mn de 5 microB (Mn2+) con cancelación parcial de la jaula Sb.
Conclusiones:
- Las propiedades magnéticas de Yb14MnSb11 están dominadas por iones Mn con una configuración d4 de alto espín (Mn2+).
- Existe una interacción magnética significativa entre los iones Mn y la jaula Sb4 circundante, lo que lleva a la cancelación parcial del momento.
- XMCD es una poderosa técnica para sondear los momentos magnéticos locales y sus interacciones en materiales complejos.
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