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Efecto Magnetocalórico Gigante a Temperatura Ambiente en Seleniuros y Sulfuros Ternarios de Metales de Transición

Yangjun Hou¹, Xiong Xu¹, Guangwei Zhai¹

¹School of Physics, Hunan Key Laboratory of Super Microstructure and Ultrafast Process, Hunan Key Laboratory of Nanophotonics and Devices, State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China.

The journal of physical chemistry letters

|February 6, 2026

Resumen

Los seleniuros y sulfuros ternarios de metales de transición muestran un potencial significativo para la refrigeración magnética a temperatura ambiente. Ti2WS4 y Ti2WSe4 exhiben grandes cambios de entropía, impulsados por la anisotropía magnética y el acoplamiento de intercambio.

Área de la Ciencia:

Ciencia de Materiales
Física de la Materia Condensada
Magnetismo

Sus antecedentes:

Los materiales bidimensionales (2D) son prometedores para tecnologías avanzadas.
La refrigeración magnética ofrece una alternativa respetuosa con el medio ambiente a la refrigeración convencional.
Es crucial desarrollar materiales con un alto efecto magnetocalórico (MCE) cerca de la temperatura ambiente.

Objetivo del estudio:

Investigar las propiedades magnéticas y el efecto magnetocalórico (MCE) de los seleniuros y sulfuros ternarios de metales de transición A2MX4.
Comprender los mecanismos subyacentes que rigen el MCE en estos materiales.
Explorar estrategias para mejorar el MCE a través de la tensión y el dopaje.

Principales métodos:

Se emplearon cálculos de primeros principios para estudiar las interacciones de intercambio magnético, la anisotropía magnética (MAE) y el MCE.
Se utilizó la teoría de perturbaciones para analizar las contribuciones al MCE.
Se investigaron los efectos de la tensión y el dopaje de portadores en la MAE y la temperatura de Curie.

Principales resultados:

Ti2WS4 y Ti2WSe4 exhiben grandes cambios de entropía (5,97 y 5,51 μJ m-2 K-1, respectivamente) cerca de la temperatura ambiente.
El fuerte acoplamiento de intercambio del segundo vecino más cercano y una gran MAE (~10 meV) contribuyen significativamente al MCE.
La MAE se atribuye al acoplamiento de los orbitales dx2-y2 y dz2 del átomo de W.
La tensión y el dopaje de portadores modulan eficazmente la MAE y la temperatura de Curie, mejorando el MCE.

Conclusiones:

Los seleniuros y sulfuros ternarios de metales de transición son candidatos prometedores para la refrigeración magnética a temperatura ambiente.
Comprender la interacción del intercambio magnético, la MAE y la estructura electrónica es clave para diseñar materiales MCE de alto rendimiento.
La tensión y el dopaje ofrecen vías viables para optimizar el MCE para aplicaciones prácticas en dispositivos de refrigeración magnética.

Palabras clave:

refrigeración magnética materiales bidimensionales seleniuros de metales de transición sulfuros de metales de transición efecto magnetocalórico anisotropía magnética temperatura de Curie cálculos de primeros principios acoplamiento de intercambio dopaje de portadores ingeniería de tensión

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