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Metalización y superconductividad en el compuesto de van der Waals CuP2Se a través del ajuste de presión del
Weiwei Li1, Jiajia Feng1, Xiaoliang Zhang1
1Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China.
Journal of the American Chemical Society
|November 23, 2021
Resumen
Las transiciones de CuP2Se en capas del semiconductor al metal bajo presión, luego se convierten en un superconductor por encima de 27 GPa. El nanodimensionamiento mejora aún más la superconductividad, ofreciendo nuevas aplicaciones para los compuestos de van der Waals.
Área de la Ciencia:
- Física de la materia condensada
- Ciencias de los materiales
- Química del estado sólido
Sus antecedentes:
- Los compuestos de van der Waals en capas (vdW) son prometedores para diversas aplicaciones.
- La superconductividad en estos materiales sigue siendo en gran medida inexplorada.
- Los compuestos vdW que contienen Cu ofrecen propiedades electrónicas únicas.
Objetivo del estudio:
- Investigar el transporte eléctrico y los cambios estructurales en el CuP2Se bajo alta presión.
- Explorar las transiciones inducidas por la presión del semiconductor al metal y del metal al superconductor.
- Comprender el papel de la presión y el nanometraje en la superconductividad.
Principales métodos:
- Experimentos de alta presión hasta ~ 60 GPa.
- Mediciones de transporte eléctrico.
- Cálculos desde el principio.
- Análisis de la evolución estructural.
Principales resultados:
- CuP2Se exhibe una transición de semiconductor a metal alrededor de 20 GPa.
- La superconductividad emerge a 3.3-5.7 K para presiones entre 27.0 y 61.4 GPa.
- Los cambios isostruturales a ~ 10 y 20 GPa indican acoplamiento y unión entre capas.
- El deslizamiento y la fusión de la capa ocurren entre 35 y 40 GPa, formando una nueva fase de alta coordinación.
- La teoría de Bardeen-Cooper-Schrieffer (BCS) describe bien la dependencia de la temperatura crítica.
- El nanodimensionamiento aumenta la temperatura crítica, incluso cerca del límite de Anderson.
Conclusiones:
- El ajuste de presión de CuP2Se induce transformaciones estructurales y electrónicas significativas, incluida la superconductividad.
- El módulo de volumen mejorado y la densidad de electrones de los estados son cruciales para la superconductividad a alta presión.
- El nanodimensionamiento ofrece una ruta para optimizar aún más la superconductividad en materiales vdW en capas.
- Los hallazgos tienen implicaciones para el diseño de nuevas aplicaciones de compuestos vdW en capas.
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