Thermal conductivity of individual silicon nanoribbons.
Nanoscale
; 8(41): 17895-17901, 2016 Oct 20.
Article
em En
| MEDLINE
| ID: mdl-27722640
ABSTRACT
The thermal conductivities of two groups of silicon nanoribbons of â¼20 and â¼30 nm thickness and various widths have been measured and analyzed through combining the Callaway model and the Fuchs-Sondheimer (FS) reduction function. The results show that while the data for the â¼30 nm thick ribbons can be well-explained by the classical size effect, the measured thermal conductivities for the â¼20 nm thick ribbons deviate from the prediction remarkably, and size effects beyond phonon-boundary scattering must be considered. The measurements of the Young's modulus of the thin nanoribbons yield significantly lower values than the corresponding bulk value, which could lead to a reduced phonon group velocity and subsequently thermal conductivity. This study helps to build a regime map for thermal conductivity versus nanostructures' surface-area-to-volume ratio that clearly delineates two regions where size effects beyond the Casimir limit are important or not important.
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Base de dados:
MEDLINE
Idioma:
En
Ano de publicação:
2016
Tipo de documento:
Article