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Intercambio aniónico y formación de la heterostructura lateral en las perovskitas bidimensionales de PEA₂Cr,Cl,Br₄

Kelly M Walsh¹, Rachel T Smith¹, Daniel R Gamelin¹

¹Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, United States.

Journal of the American Chemical Society

|October 9, 2024

Resumen

Los investigadores lograron el intercambio aniónico posintético en perovskitas ferromagnéticas 2D, creando interfaces magneto-hetero laterales PEA2CrCl4 / PEA2CrBr4. Esto avanza en la comprensión del intercambio iónico en perovskitas 2D para nuevos efectos de espín.

Área de la Ciencia:

Ciencias de los materiales
Química del estado sólido
Física de la materia condensada

Sus antecedentes:

Las perovskitas híbridas de haluros metálicos bidimensionales ofrecen propiedades únicas para la espintrónica.
El control de la composición y la creación de heteroestructuras en estos materiales es crucial para aplicaciones avanzadas.
La comprensión de los mecanismos de intercambio iónico es clave para adaptar las propiedades de la perovskita.

Objetivo del estudio:

Para demostrar el intercambio de aniones de la fase de vapor posintética en perovskitas ferromagnéticas 2D.
Para crear interfaces magneto-hetero laterales en el PEA2CrCl4.
Investigar la cinética y los mecanismos de intercambio aniónico en perovskitas 2D.

Principales métodos:

Intercambio de aniones en fase de vapor después de la síntesis utilizando bromuro de trimetilsililo (TMS-Br).
Espectroscopia de dicroísmo magnético circular de baja temperatura para caracterizar el ordenamiento magnético.
Estudios cinéticos y comparación entre las diferentes composiciones de perovskita (PEA2CrCl4, MA2CrCl4, PEA2MnCl4, PEA2PbCl4).

Principales resultados:

Conversión completa de PEA2CrCl4 a PEA2CrBr4 mediante el intercambio de aniones en la fase de vapor.
Generación exitosa de las abruptas interfaces magneto-hetero laterales PEA2CrCl4/PEA2CrBr4.
Se ha demostrado la supresión de la difusión 3D por medio de cationes de PEA+ voluminosos y la difusión de bromuro 2D más lenta en PEA2CrCl4 debido al ordenamiento antiferrodistortivo.

Conclusiones:

El control de la composición posintética y la formación de la heterostructura se pueden lograr en perovskitas 2D basadas en Cr ferromagnéticas.
El intercambio aniónico de la fase de vapor proporciona una ruta para diseñar nuevos efectos de espín en perovskitas de haluro metálico de baja dimensión.
El voluminoso catión PEA + y el ordenamiento del material intrínseco influyen significativamente en las vías de difusión de iones.

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