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Efecto magnetocalórico en AlFe2B2: hacia los refrigerantes magnéticos de los elementos abundantes en la tierra
Xiaoyan Tan1, Ping Chai, Corey M Thompson
1Department of Chemistry and Biochemistry, Florida State University, 95 Chieftan Way, Tallahassee, Florida 32306, United States.
Journal of the American Chemical Society
|June 5, 2013
Resumen
Los investigadores desarrollaron AlFe2B2, un material magnético ligero. Muestra un efecto magnetocalórico significativo (MCE) cerca de la temperatura ambiente, lo que lo convierte en una alternativa prometedora a los elementos de tierras raras.
Área de la Ciencia:
- Ciencia de los materiales Ciencia de los materiales.
- Física de la materia condensada Física de la materia condensada
- Química del estado sólido.
Sus antecedentes:
- La búsqueda de materiales magnetocalóricos eficientes es crucial para el desarrollo de tecnologías de refrigeración avanzadas.
- Los boruros metálicos en capas ofrecen potencial para nuevas propiedades y aplicaciones magnéticas.
- Los elementos de tierras raras, a menudo utilizados en materiales magnetocalóricos, enfrentan desafíos de oferta y costo.
Objetivo del estudio:
- Para sintetizar y caracterizar el compuesto AlFe2B2.
- Para investigar las propiedades magnéticas y magnetocalóricas de AlFe2B2.2.
- Evaluar el potencial de AlFe2B2 como material magnetocalórico libre de tierras raras.
Principales métodos:
- Síntesis a través de la fusión por arco y los métodos de flujo de Ga.
- Análisis estructural de la estructura cristalina en capas.
- Mediciones magnéticas para determinar el ferromagnetismo y la temperatura de ordenamiento.
- Mediciones del efecto magnetocalórico (MCE) en función del campo magnético.
Principales resultados:
- AlFe2B2 fue sintetizado con éxito, revelando una estructura en capas con capas alternas de Al y [Fe2B2].
- El compuesto exhibe ferromagnetismo itinerante con una temperatura de Curie de 307 K.
- Se observaron efectos magnetocalóricos significativos: 4.1 J kg{-1) K{-1) a las 2 T y 7.7 J kg{-1) K{-1) a las 5 T. Se observaron efectos magnetocalóricos significativos: 4.1 J kg{-1) K{-1) a las 2 T y 7.7 J kg{-1) K{-1) a las 5 T.
- Estos valores de MCE son los más altos reportados para los boruros metálicos y los materiales de la familia 122 cerca de la temperatura ambiente.
Conclusiones:
- AlFe2B2 es un prometedor material magnetocalórico libre de tierras raras.
- Su naturaleza ligera y el uso de elementos abundantes en la tierra lo hacen ecológicamente benigno y rentable.
- El MCE sustancial cerca de la temperatura ambiente destaca su potencial para aplicaciones de refrigeración magnética.
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