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Baja conductividad térmica en un material inorgánico modular con anisotropía de enlace y desajuste
Quinn D Gibson1, Tianqi Zhao2, Luke M Daniels1
1Department of Chemistry, University of Liverpool, Crown Street, Liverpool L69 7ZD, UK.
Science (New York, N.Y.)
|August 27, 2021
Resumen
Los investigadores lograron una conductividad térmica ultra baja en materiales en capas mediante el control del comportamiento de los fonones. Este avance en la ciencia de los materiales ofrece el potencial para aplicaciones avanzadas de gestión térmica.
Área de la Ciencia:
- Ciencias de los materiales
- Física de la materia condensada
- Química del estado sólido
Sus antecedentes:
- Los materiales cristalinos tienen un límite mínimo de conductividad térmica intrínseca determinado por la dispersión de fonones.
- El control del transporte de fonones es crucial para el desarrollo de materiales con propiedades térmicas adaptadas.
Objetivo del estudio:
- Explorar estrategias para suprimir las contribuciones longitudinales y transversales de los fonones al transporte de calor en materiales en capas.
- Lograr una conductividad térmica extremadamente baja mediante interfaces de ingeniería química dentro de estructuras de superretícula.
Principales métodos:
- Utilizó estrategias complementarias para apuntar a los modos fonónicos longitudinales y transversales.
- Materiales en capas sintetizados y caracterizados, incluidos BiOCl, Bi2O2Se y la superred Bi4O4SeCl2.
- Investigó la relación entre la disposición de la interfaz química y la modificación del modo vibratorio.
Principales resultados:
- Se ha demostrado que BiOCl y Bi2O2Se suprimen eficazmente los fonones longitudinales y transversales, respectivamente.
- Se obtiene una conductividad térmica excepcionalmente baja a temperatura ambiente de 0,1 W/K·m en Bi4O4SeCl2 a lo largo de la dirección de apilamiento.
- Este valor es comparable a la conductividad térmica del aire, lo que indica una dispersión significativa de fonones.
Conclusiones:
- El control químico sobre la disposición espacial de las distintas interfaces modifica sinérgicamente los modos vibratorios.
- Este enfoque permite una minimización significativa de la conductividad térmica en materiales cristalinos en capas.
- Los hallazgos abren nuevas vías para el diseño de materiales con conductividad térmica ultra baja para la gestión térmica.
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