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Bistabilidad sin precedentes en sólidos de espín cruzado basado en la retroacción de la interfaz de alto espín de

Miguel Paez-Espejo¹, Mouhamadou Sy¹, Kamel Boukheddaden¹

¹Groupe d'Etudes de la Matière Condensée, UMR 8635 , CNRS-Université de Versailles Saint-Quentin-en-Yvelines , 45 Avenue des Etats Unis , 78035 Versailles , France.

Journal of the American Chemical Society

|September 1, 2018

Resumen

Los sólidos de cruce de espín exhiben un movimiento de interfaz reversible entre las fases de alto y bajo espín. La flexión de cristal controla la rotación de la interfaz, permitiendo nuevos sensores de tensión que evitan problemas de fatiga.

Área de la Ciencia:

Ciencias de los materiales
Física del estado sólido
Química

Sus antecedentes:

Los sólidos de cruce de espín (SCO) experimentan transiciones de fase de primer orden entre los estados de alto espín (HS) y bajo espín (LS).
Estas transiciones en cristales individuales implican la nucleación y propagación del dominio, con interfaces que exhiben dinámicas complejas.
Los cambios unitarios anisotrópicos conducen a orientaciones simétricas de la interfaz entre las fases HS y LS.

Objetivo del estudio:

Investigar experimentalmente la dinámica reversible de traslación y rotación de la interfaz HS-LS en sólidos SCO.
Comprender la influencia de la deformación macroscópica del cristal, específicamente la flexión, en la orientación de la interfaz.
Explorar el potencial para desarrollar nuevos sensores de tensión basados en las propiedades de los materiales SCO.

Principales métodos:

Observación experimental del movimiento de la interfaz en cristales simples SCO.
Caracterización del desplazamiento de la interfaz y la rotación entre ángulos estables (60° y 120°).
Modelado teórico elástico que simula el efecto de la flexión del cristal utilizando momentos de fuerza aplicados.

Principales resultados:

Se ha demostrado el control reversible de la traslación y rotación de la interfaz HS-LS.
La rotación de la interfaz está vinculada a la flexión del cristal, mientras que la traducción se acompaña de un cambio de longitud.
Inestabilidad de la orientación de la interfaz observada más allá de una carga umbral, indicando bistabilidad a volumen constante.

Conclusiones:

La flexión macroscópica del cristal influye críticamente en la orientación de la interfaz HS-LS en los sólidos SCO.
La sensibilidad observada permite el desarrollo de sensores de tensión robustos que funcionan a volumen constante.
Este enfoque mitiga los problemas de fatiga del material comunes en los sensores convencionales.

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