Electromechanical resonance behavior of suspended single-walled carbon nanotubes under high bias voltages
| Autor: | I-Kai Hsu, Zuwei Liu, Stephen B. Cronin, Shun-Wen Chang, Mehmet Aykol, William Branham, Rohan Dhall, Moh. R. Amer |
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| Rok vydání: | 2011 |
| Předmět: |
Nanotube
Materials science Condensed matter physics Phonon Mechanical Engineering Biasing Nanotechnology High voltage Carbon nanotube Condensed Matter::Mesoscopic Systems and Quantum Hall Effect Electronic Optical and Magnetic Materials law.invention symbols.namesake Negative thermal expansion Mechanics of Materials law symbols Mechanical resonance Electrical and Electronic Engineering Raman spectroscopy |
| Zdroj: | Journal of Micromechanics and Microengineering. 21:085008 |
| ISSN: | 1361-6439 0960-1317 |
| Popis: | We characterize the nanoelectromechanical response of suspended individual carbon nanotubes under high voltage biases. An abrupt upshift in the mechanical resonance frequency of approximately 3 MHz is observed at high bias. While several possible mechanisms are discussed, this upshift is attributed to the onset of optical phonon emission, which results in a sudden contraction of the nanotube due to its negative thermal expansion coefficient. This, in turn, causes an increase in the tension in the suspended nanotube, which upshifts its mechanical resonance frequency. This upshift is consistent with Raman spectral measurements, which show a sudden downshift of the optical phonon modes at high bias voltages. Using a simple model for oscillations on a string, we estimate the effective change in the length of the nanotube to be ΔL/L ≈ −2 × 10−5 at a bias voltage of 1 V. |
| Databáze: | OpenAIRE |
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