Nano Carbon 1D and 2D Nanomechanical Resonators

ABSTRACTWe demonstrate one-dimensional (1D) and two-dimensional (2D) resonant nanoelectromechanical systems (NEMS) derived from nano carbon materials, where the resonance frequency and the quality (Q) factor of the devices are measured experimentally using ultrasensitive optical interferometry. The 1D nano carbon resonators are formed using carbon nanofibers (CNFs) which are synthesized using a plasma-enhanced chemical vapor deposition (PECVD) process, while the 2D nanocarbon resonators are based on CVD grown graphene. The CNFs are prototyped into few-μm-long cantilever-shaped 1D resonators, where the resonance frequency and Qs are extracted from measurements of the undriven thermomechanical noise spectrum. The thermomechanical noise measurements yield resonances in the ∼3–15 MHz range, with Q of ∼200–800. Significant changes in resonance characteristics are observed due to electron beam induced amorphous carbon deposition on the CNFs, which suggests that 1D CNF resonators have strong prospects for ultrasensitive mass detection. We also present NEMS resonators based on 2D graphene nanomembranes, which exhibit robust undriven thermomechanical resonances for the extraction of ultrasmall strain levels.

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Tuning of electronic properties of chemical vapor deposition grown graphene via self-assembled monolayer doping

Materials Today Proceedings ◽

10.1016/j.matpr.2020.11.352 ◽

2020 ◽

Author(s):

Anand Kumar Singh ◽

Vivek Chaudhary ◽

Arun Kumar Singh ◽

S.R.P. Sinha

Keyword(s):

Chemical Vapor Deposition ◽

Electronic Properties ◽

Vapor Deposition ◽

Chemical Vapor ◽

Self Assembled Monolayer ◽

Self Assembled ◽

Grown Graphene

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Reliability and stability of thin-film amorphous silicon MEMS on glass substrates

MRS Proceedings ◽

10.1557/opl.2011.253 ◽

2011 ◽

Vol 1299 ◽

Author(s):

P. M. Sousa ◽

V. Chu ◽

J. P. Conde

Keyword(s):

Thin Film ◽

Resonance Frequency ◽

Frequency Shift ◽

Amorphous Silicon ◽

Structural Damage ◽

Chemical Vapor ◽

Stability Study ◽

Glass Substrates ◽

Resonance Frequency Shift ◽

Mems Resonators

ABSTRACTIn this work, we present a reliability and stability study of doped hydrogenated amorphous silicon (n+-a-Si:H) thin-film silicon MEMS resonators. The n+-a-Si:H structural material was deposited using radio frequency plasma enhanced chemical vapor deposition (RF-PECVD) and processed using surface micromachining at a maximum deposition temperature of 110 ºC. n+-a-Si:H resonant bridges can withstand the industry standard of 1011 cycles at high load with no structural damage. Tests performed up to 3x1011 cycles showed a negligible level of degradation in Q during the entire cycling period which in addition shows the high stability of the resonator. In measurements both in vacuum and in air a resonance frequency shift which is proportional to the number of cycles is established. This shift is between 0.1 and 0.4%/1x1011 cycles depending on the applied VDC. When following the resonance frequency in vacuum during cyclic loading, desorption of air molecules from the resonator surface is responsible for an initial higher resonance frequency shift before the linear dependence is established.

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Micro-crystalline diamond and nano-carbon structures produced using a high argon concentration in hot-filament chemical vapor deposition

Journal of Vacuum Science & Technology A Vacuum Surfaces and Films ◽

10.1116/1.1366701 ◽

2001 ◽

Vol 19 (4) ◽

pp. 1057-1062 ◽

Cited By ~ 8

Author(s):

Vitor Baranauskas ◽

Alfredo C. Peterlevitz ◽

Helder J. Ceragioli ◽

Steven F. Durrant

Keyword(s):

Chemical Vapor Deposition ◽

Vapor Deposition ◽

Chemical Vapor ◽

Carbon Structures ◽

Argon Concentration ◽

Nano Carbon ◽

Hot Filament

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Gas products and carbon deposition kinetics in chemical vapor deposition from propylene

New Carbon Materials ◽

10.1016/s1872-5805(09)60014-7 ◽

2010 ◽

Vol 25 (1) ◽

pp. 35-40 ◽

Cited By ~ 5

Author(s):

Cui-ying LU ◽

Lai-fei CHENG ◽

Li-tong ZHANG ◽

Chun-nian ZHAO

Keyword(s):

Chemical Vapor Deposition ◽

Vapor Deposition ◽

Carbon Deposition ◽

Chemical Vapor ◽

Deposition Kinetics ◽

Gas Products

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Microtremor measurements used to map thickness of soft sediments

Bulletin of the Seismological Society of America ◽

10.1785/bssa0890010250 ◽

1999 ◽

Vol 89 (1) ◽

pp. 250-259

Author(s):

Malte Ibs-von Seht ◽

Jürgen Wohlenberg

Keyword(s):

Cross Sections ◽

Vertical Component ◽

Noise Spectrum ◽

Main Peak ◽

Spectral Ratios ◽

Wide Range ◽

Noise Measurements ◽

Cover Thickness ◽

Microtremor Measurements ◽

Lower Rhine Embayment

Abstract The observations about the behavior of microtremor spectra presented here show that noise measurements can be used as a powerful tool to determine the thickness of soft cover layers. The most suitable method for this determination is Nakamura's technique, which is the ratio of the horizontal-component noise spectrum and that of the vertical component (H/V spectrum). The frequency of the main peak in these spectral ratios correlates well with the sediment thickness at the site. Using an extensive database of microtremor measurements carried out in the western Lower Rhine Embayment (Germany), it was possible to show that this correlation is clearly valid for a wide range of thickness, namely, from tens of meters to more than 1000 m. A simple formula was derived that, for the sediments to be found in the area investigated, directly calculates the cover thickness from the frequency of the main peak in the H/V spectrum. A comparison with calculated resonant frequencies suggests the relation derived from the noise measurements depending on the velocity depth function of the shear wave. Classical spectral ratios are shown to be strongly influenced by the noise level and are therefore less reliable in determining the resonant frequency of the subsoil. The practical relevance of the investigation is illustrated by means of cross sections, constructed from results of the microtremor analyses, which provide a convincing image of the surficial structure of the areas investigated.

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1/f Noise in Mott Variable Range Hopping Conduction in p-type Amorphous Silicon

MRS Proceedings ◽

10.1557/opl.2015.546 ◽

2015 ◽

Vol 1770 ◽

pp. 25-30 ◽

Cited By ~ 3

Author(s):

V.C. Lopes ◽

A.J. Syllaios ◽

D. Whitfield ◽

K. Shrestha ◽

C.L. Littler

Keyword(s):

Electrical Conductivity ◽

Amorphous Silicon ◽

Chemical Vapor ◽

Variable Range Hopping ◽

Temperature Dependent ◽

Noise Component ◽

Variable Range ◽

Noise Measurements ◽

P Type ◽

Hydrogenated Amorphous

ABSTRACTWe report on electrical conductivity and noise measurements made on p-type hydrogenated amorphous silicon (a-Si:H) thin films prepared by Plasma Enhanced Chemical Vapor Deposition (PECVD). The temperature dependent electrical conductivity can be described by the Mott Variable Range Hopping mechanism. The noise at temperatures lower than ∼ 400K is dominated by a 1/f component which follows the Hooge model and correlates with the Mott conductivity. At high temperatures there is an appreciable G-R noise component.

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Preparation and growth mechanism of one-dimensional NdB6 nanostructures: nanobelts, nanoawls, and nanotubes

RSC Advances ◽

10.1039/c6ra02000c ◽

2016 ◽

Vol 6 (48) ◽

pp. 41891-41896 ◽

Cited By ~ 5

Author(s):

Wei Han ◽

Yanming Zhao ◽

Qinghua Fan ◽

Qidong Li

Keyword(s):

Chemical Vapor Deposition ◽

Growth Mechanism ◽

Vapor Deposition ◽

Chemical Vapor ◽

One Dimensional

1D NdB6 nanostructures (nanobelts, nanoawls, and nanotubes) have been synthesized through a chemical vapor deposition (CVD) process with a self-catalyzed mechanism.

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