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Superconductividad a 43 K en un compuesto en capas a base de hierro LaO(1-x) F(x) FeAs
Hiroki Takahashi1, Kazumi Igawa, Kazunobu Arii
1Department of Physics, College of Humanities and Sciences, Nihon University, Sakurajosui, Setagaya-ku, Tokyo 156-8550, Japan. hiroki@chs.nihon-u.ac.jp
Nature
|April 25, 2008
Resumen
La aplicación de presión a los superconductores LaOFeAs dopados con flúor aumenta significativamente su temperatura crítica (T (c)). Esta investigación pone de relieve oxypnictides de hierro como una nueva plataforma prometedora para el descubrimiento de la superconductividad a alta temperatura.
Área de la Ciencia:
- Física de la materia condensada Física de la materia condensada
- Ciencia de los materiales Ciencia de los materiales.
- La superconductividad es la superconductividad.
Sus antecedentes:
- Los compuestos basados en hierro y níquel en capas como LaOFeP y LaONiP exhiben superconductividad a baja temperatura.
- El dopaje de fluoruro en LaOFeAs (LaO(1-x) F(x) FeAs) aumentó su temperatura de transición superconductora (T(c)) a aproximadamente 26 K.
- La superconductividad en estos materiales a menudo está relacionada con la inestabilidad magnética, con T (c) influenciado por el dopaje de la portadora y la transferencia de carga.
Objetivo del estudio:
- Para investigar el efecto de la presión externa en la temperatura de transición superconductora (T ((c)) de LaOFeAs dopados con flúor.
- Para explorar el potencial de oxypnictides de hierro en capas como una plataforma material para lograr temperaturas de transición superconductoras más altas.
Principales métodos:
- Aplicación experimental de presión externa a muestras de LaOFeAs dopadas con flúor.
- Medición de la temperatura de transición superconductora (T(c)) bajo condiciones de presión variables.
- Análisis de la relación entre la presión, la transferencia de carga y la superconductividad en oxypnictides de hierro.
Principales resultados:
- El aumento de la presión condujo a un fuerte aumento en el inicio de T (c) de F-doped LaOFeAs.
- Se logró una Tc máxima de aproximadamente 43 K a aproximadamente 4 GPa.
- Esto representa uno de los valores más altos de T (c) reportados hasta la fecha, excluyendo los superconductores de alta T (c) basados en cobre.
Conclusiones:
- La presión externa mejora significativamente la superconductividad en los LaOFeAs dopados con flúor.
- La compresibilidad del ion As y una mayor transferencia de carga contribuyen al aumento de T (c) inducido por la presión.
- Los oxypnictides de hierro en capas (LnOTMPn) ofrecen una plataforma material prometedora para el descubrimiento de nuevos superconductores de alta temperatura.
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