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Observación inicial de la histeresis de magnetización y el túnel cuántico en imanes de una sola molécula de
Abhudaya Mishra1, Wolfgang Wernsdorfer, Khalil A Abboud
1Department of Chemistry, University of Florida, Gainesville, Florida 32611-7200, USA.
Journal of the American Chemical Society
|December 2, 2004
Resumen
Los investigadores sintetizaron nuevos grupos mixtos de metales de transición y lantánidos. El grupo que contiene disprosio exhibe un comportamiento magnético de una sola molécula, incluida la histeresis y el túnel cuántico.
Área de la Ciencia:
- Química Inorgánica La Química Inorgánica es la química inorgánica.
- Ciencia de los materiales Ciencia de los materiales.
- El magnetismo es el magnetismo.
Sus antecedentes:
- Los grupos mixtos de metales de transición / lantánidos son de interés por sus propiedades magnéticas únicas.
- Los imanes de molécula única (SMM) son compuestos moleculares que exhiben histeresis magnética por debajo de una temperatura de bloqueo.
Objetivo del estudio:
- Para sintetizar y caracterizar una nueva familia de grupos mixtos de metales de transición / lantánidos.
- Investigar las propiedades magnéticas de estos nuevos cúmulos, particularmente para el comportamiento de los SMM.
Principales métodos:
- Reacción de un precursor de clúster de manganeso con los nitratos lantánidos (Nd, Gd, Dy, Ho, Eu).
- Cristalización y caracterización de los complejos de núcleos [Mn11Ln4]45+ resultantes.
- Mediciones de susceptibilidad magnética (AC y DC) para sondear el comportamiento magnético.
Principales resultados:
- Síntesis exitosa de una nueva familia de cúmulos mixtos 3d/4f con un núcleo [Mn11Ln4]45+.
- El complejo que contiene disprosio demostró señales de susceptibilidad AC fuera de fase, indicativas del comportamiento de SMM.
- Se observaron bucles de histeresis de magnetización y una barrera de energía de 9,3 K para el compuesto Dy.
- Evidencia de relajación independiente de la temperatura a bajas temperaturas, lo que sugiere un túnel cuántico de la magnetización.
Conclusiones:
- Este trabajo informa de los primeros imanes mixtos 3d/4f de una sola molécula que exhiben histeresis.
- El túnel cuántico de magnetización observado en estos sistemas abre nuevas vías para la investigación del magnetismo molecular.
- Estos hallazgos contribuyen al desarrollo de materiales magnéticos avanzados.
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