Anharmonic properties of Raman modes in double wall carbon nanotubes
The temperature dependence of the radial breathing modes (RBMs) and the zone-center tangential optical phonons (G-bands) of double-walled carbon nanotubes (DWCNTs) has been investigated between 300 and 700 K using Raman scattering. As expected, with increasing temperature, the frequencies of the Ram...
| Autores: | , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2011 |
| País: | España |
| Institución: | Universidad de Cantabria (UC) |
| Repositorio: | UCrea Repositorio Abierto de la Universidad de Cantabria |
| Idioma: | inglés |
| OAI Identifier: | oai:repositorio.unican.es:10902/21954 |
| Acceso en línea: | http://hdl.handle.net/10902/21954 |
| Access Level: | acceso abierto |
| Palabra clave: | Espectroscopia raman Nanotubos de carbono doble pared Altas temperaturas Anarmonicidad Parámetro Grüneisen. |
| Sumario: | The temperature dependence of the radial breathing modes (RBMs) and the zone-center tangential optical phonons (G-bands) of double-walled carbon nanotubes (DWCNTs) has been investigated between 300 and 700 K using Raman scattering. As expected, with increasing temperature, the frequencies of the Raman peaks, including the RBMs and G-bands downshift simultaneously. We show here that the temperature dependence of the RBMs can be fitted by a simple linear dependence and different RBMs have different frequency shifts. We observe a noticeable nonlinearity in the temperature dependence of the G-band associated with the outer semiconducting tube (s). The deviation from the linear trend is due to the contribution of the third-order anharmonic term in the lattice potential energy with a pure temperature effect. An estimated value of 1.5 for the Grüneisen parameter of the (s) band was found. |
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