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La amorfización inducida por presión y una transición amorfo-amorfo en el silicio poroso densificado
S K Deb1, M Wilding, M Somayazulu
1Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085, India.
Nature
|December 6, 2001
Resumen
La compresión de las películas porosas de silicio induce amorfización por encima de 10 GPa. Tras la descompresión, se produce una transición de fase amorfa-silicio única, que refleja el agua.
Área de la Ciencia:
- Ciencia de los materiales Ciencia de los materiales.
- Física de la materia condensada Física de la materia condensada
- Nanotecnología La nanotecnología es la nanotecnología.
Sus antecedentes:
- El silicio es un material clave en la electrónica y la energía fotovoltaica.
- Las transiciones masivas de silicio a fases metálicas bajo presión.
- El silicio nanocristalino exhibe cambios estructurales inducidos por la presión únicos.
Objetivo del estudio:
- Investigar el comportamiento del silicio poroso bajo compresión.
- Caracterizar la amorfización inducida por presión en las películas porosas de silicio.
- Explorar el comportamiento de descompresión de las fases amorfas resultantes.
Principales métodos:
- Experimentos de compresión en películas porosas de silicio.
- Espectroscopia Raman para el análisis estructural.
- Mediciones de alta presión superiores a 10 GPa.
Principales resultados:
- El silicio poroso sufre amorfización inducida por presión por encima de 10 GPa.
- Se forma una fase de silicio amorfo de alta densidad.
- Tras la descompresión, esto se transforma en una fase de silicio amorfo de baja densidad.
Conclusiones:
- El silicio poroso exhibe un comportamiento distinto de amorfización y descompresión en comparación con el silicio a granel.
- La transición amorfa-amorfa observada sugiere una transición similar a la fase líquida en el silicio súper enfriado.
- Este hallazgo ofrece nuevos conocimientos sobre el complejo diagrama de fase del silicio en condiciones extremas.
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