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Espectroscopia vibratoria en el microscopio electrónico
Ondrej L Krivanek1, Tracy C Lovejoy2, Niklas Dellby2
11] Nion Company, 1102 Eighth Street, Kirkland, Washington 98033, USA [2] Department of Physics, Arizona State University, Tempe, Arizona 85287, USA.
Nature
|October 10, 2014
Resumen
La espectroscopia vibratoria de alta resolución ahora es posible en microscopios electrónicos. Este avance permite un análisis detallado de los nanomateriales y sus modos de vibración, incluso la detección de hidrógeno, con un daño mínimo de radiación.
Área de la Ciencia:
- Ciencia de los materiales Ciencia de los materiales.
- La espectroscopia es una técnica de espectroscopia.
- Nanotecnología La nanotecnología es la nanotecnología.
Sus antecedentes:
- Las espectroscopias vibratorias son cruciales para el análisis de materiales, pero por lo general carecen de una alta resolución espacial.
- Los métodos existentes como la espectroscopia infrarroja y Raman ofrecen una resolución espacial limitada (de micrómetros a nanómetros).
- La microscopía electrónica de transmisión (TEM) proporciona una alta resolución espacial, pero carece de la resolución de energía para la espectroscopia vibratoria.
Objetivo del estudio:
- Para permitir la espectroscopia vibratoria dentro de un microscopio electrónico de transmisión (TEM).
- Para lograr una resolución espacial a nivel nanométrico para el análisis vibratorio de materiales.
- Explorar nuevas aplicaciones de la espectroscopia vibratoria en las nanoestructuras.
Principales métodos:
- Utilizando los recientes avances en la espectroscopia de pérdida de energía de electrones (EELS) dentro de un microscopio electrónico de transmisión de barrido (STEM).
- Alcanzando una resolución de energía de aproximadamente diez milielectronvoltios (meV).
- Desarrollo de técnicas para el análisis de señales vibratorias de alta y baja resolución espacial.
Principales resultados:
- Se ha demostrado el éxito de la espectroscopia vibratoria con resolución a nivel nanométrico en un TEM.
- Aplicó la técnica para analizar materiales inorgánicos y orgánicos, incluyendo la detección de hidrógeno.
- Se mostró la espectroscopia "a distancia" para el análisis con daños reducidos por radiación.
Conclusiones:
- La resolución mejorada de EELS en STEM ahora permite la espectroscopia vibratoria en microscopios electrónicos.
- Esta técnica abre nuevas vías para el estudio de los modos vibratorios en diversas nanoestructuras.
- La señal de doble componente permite el mapeo de alta resolución y la espectroscopia a distancia con daños minimizados.
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