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Banda de valencia extremadamente superficial en el trihidruro de lantano

Tomoyuki Yamasaki¹, Soshi Iimura^1,2,3, Junghwan Kim^1,3

¹International Research Frontiers Initiative MDX Research Center for Element Strategy, Tokyo Institute of Technology, Yokohama 226-8503, Japan.

Journal of the American Chemical Society

|December 21, 2022

Resumen

Los investigadores estudiaron los iones hidruro en los hidruros de lantano utilizando espectroscopia y cálculos. Encontraron un máximo de banda de valencia superficial en LaH3, crucial para comprender los semiconductores de hidrógeno y los superconductores.

Área de la Ciencia:

Química del estado sólido
Ciencias de los materiales
Química cuántica

Sus antecedentes:

Los iones hidruro (H-) son potentes agentes reductores en la química orgánica debido a su fuerte capacidad de donación de electrones.
Comprender la estructura electrónica de los hidritos es clave para el desarrollo de nuevos materiales.

Objetivo del estudio:

Para investigar el nivel de energía de los electrones 1s en los iones hidruro dentro de los hidruros sólidos de lantano (LaHx, 2 ≤ x ≤ 3).
Explorar las propiedades electrónicas de los hidruros de lantano para aplicaciones potenciales en semiconductores y superconductores.

Principales métodos:

Espectroscopía de fotoemisión (espectroscopía de rendimiento de fotoelectrones y fotoelectrones ultravioleta).
Cálculos de la teoría funcional de la densidad (DFT).

Principales resultados:

Se observó un máximo de banda de valencia muy superficial en el trihidruro de lantano (LaH3), correspondiente a un potencial de ionización de 3,8 eV.
La banda de poca profundidad se atribuye a la baja electronegatividad del hidrógeno y las fuertes interacciones de enlace H-H en la estructura relacionada con la fluorita.
Se aclaró la estructura electrónica de LaH3, revelando las características clave del enlace hidruro.

Conclusiones:

Los hallazgos proporcionan una base para la búsqueda de la conducción de tipo p en semiconductores hidruro.
Esta investigación ofrece información sobre las bases químicas de la superconductividad de los polihidruros.

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