Respuesta de la superconductividad y la estructura cristalina de LiFeAs a la presión hidrostática
Masaki Mito1, Michael J Pitcher, Wilson Crichton
1Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory, South Parks Road, Oxford, OX1 3QR, United Kingdom.
Journal of the American Chemical Society
|February 12, 2009
Resumen
La presión hidrostática disminuye la superconductividad en LiFeAs. Este material muestra una compresibilidad única debido a su pequeño ion de litio, impactando la estructura tetraédrica FeAs4 y las propiedades superconductoras.
Área de la Ciencia:
- Física del estado sólido Física del estado sólido
- Ciencia de los materiales Ciencia de los materiales.
- La superconductividad es la superconductividad.
Sus antecedentes:
- El arseniuro de litio y hierro (LiFeAs) es un superconductor significativo a base de hierro.
- Comprender los efectos de la presión en sus propiedades superconductoras es crucial para el diseño de materiales.
Objetivo del estudio:
- Para investigar el impacto de la presión hidrostática en la temperatura de transición superconductora (T ((c)) de LiFeAs.
- Para caracterizar la compresibilidad y la respuesta estructural de LiFeAs bajo alta presión.
Principales métodos:
- Las temperaturas de transición superconductoras se midieron bajo presiones hidrostáticas de hasta 1,3 GPa.
- Se utilizó la difracción de polvo de rayos X para analizar cambios estructurales de hasta 17 GPa utilizando una célula de yunque de diamante y un medio de presión de gas de helio.
Principales resultados:
- Las temperaturas de transición superconductoras (T (((c)) disminuyeron monotónicamente con una presión a una velocidad de aproximadamente -2 K GPa ((-1).
- LiFeAs exhibe un bajo módulo de volumen (57,3 GPa) y compresión isotrópica en comparación con otros superconductores en capas.
- El aumento de la presión conduce a una distorsión significativa de los tetraedros FeAs, con las distancias Fe-Fe que se contraen más que las distancias Fe-As.
Conclusiones:
- La disminución observada en T (c) bajo presión es consistente con la correlación entre T (c) óptima y los tetraedros regulares de FeAs (d) en los superconductores a base de hierro.
- La compresibilidad única de LiFeAs, atribuida al pequeño ion de litio, influye significativamente en su comportamiento estructural y superconductor bajo presión.
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