G-band Raman Spectra of Isolated Single Wal Carbon Nanotubes: Diameter and Chiraity Dependence

Jório, Ado; Filho, A. G. Souza; Dresselhaus, G.; Dresselhaus, M. S.; Swan, Anna K.; Ünlü, M. Selim; Goldberg, Bennett B.; Pimenta, M. A.; Hafner, Jason H.; Lieber, Charles M.; Saito, Riichiro

doi:10.1557/proc-706-z6.19.1

Cited by 17 publications

(28 citation statements)

References 9 publications

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“…It can be seen that while for RBM the cyclacenes represented a reasonable model, for o + G they provide too low frequencies no matter what l-family is inspected. The 4-unit models provide frequencies at an average of B1608 cm À1 , which is slightly above experimental values 65 found for tubes with d 4 1 nm, nevertheless still closer to experiment than the cyclacenes' values with an average of B1530 cm À1 . The 4-unit model provides already converged results with respect to the model length, because the o + G frequencies obtained using other two longer models are almost identical.…”

Section: Tangential G-bandsupporting

confidence: 64%

“…5), is only negligibly dependent on the tube diameter. 65 In contrast, o À G (B1550 cm À1 ) corresponding to vibrations along the circumferential direction should depend on diameter d. The difference between SWCNT bundles and isolated nanotubes is small in this region (D B 2 cm À1 ). The isolated SWCNTs provide bands with significantly smaller widths (B10 cm À1 compared to B20 cm À1 in SWCNT bundles 65,67,109 ).…”

Section: Tangential G-bandmentioning

confidence: 95%

“…65 In contrast, o À G (B1550 cm À1 ) corresponding to vibrations along the circumferential direction should depend on diameter d. The difference between SWCNT bundles and isolated nanotubes is small in this region (D B 2 cm À1 ). The isolated SWCNTs provide bands with significantly smaller widths (B10 cm À1 compared to B20 cm À1 in SWCNT bundles 65,67,109 ). In this work we investigated the o + G (A 1g ) and o À G (E 1g ) frequencies for narrower SWCNTs of a diameter from 0.4 to 1.2 nm.…”

Section: Tangential G-bandmentioning

confidence: 95%

“…The symmetry of the system thus lowers and two new directions (axial and circumferential) can be distinguished. 58,65 The shape of the G-band between 1500 and 1600 cm À1 allows distinguishing between semiconducting and metallic nanotubes. Two differently intense peaks are usually observed within the G-band region of semiconducting SWCNTs.…”

Section: Introductionmentioning

confidence: 99%

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Calculation of Raman parameters of real-size zigzag (n, 0) single-walled carbon nanotubes using finite-size models

Kupka

Stachów

Stobiński

et al. 2016

Phys. Chem. Chem. Phys.

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Structural and selected Raman features of pristine single-walled carbon nanotubes (SWCTNs) with diameters from 0.4 to 1.2 nm and total lengths up to 2.15 nm were studied using the density functional theory (DFT) at the UB3LYP/6-31G* level. Models of different lengths (1, 4, 6 and 10 adjacent bamboo-units) of zigzag (n, 0) SWCNTs, for n ranging from 5 to 15, were studied. Highly systematic changes of individual CC bond lengths and angles along the nanotube axis were observed and described for the longest models. Predicted Raman active radial breathing mode (RBM) vibrational frequencies regularly decreased upon increasing the nanotube diameter and only a negligible effect of the tube length was observed. The changes in calculated RBM frequencies with increasing diameter were close to values estimated using empirical formulas. The experimental G-mode characteristics were reasonably well reproduced using the 4-unit model, especially for tubes with the diameter d > 1 nm. Raman features were also determined for cyclacenes representing the shortest models of SWCNTs. Calculated RBM frequencies of cyclacenes match closely the values for longer SWCNT models but are too inaccurate in the case of the G-mode. For the first time, the Raman properties of SWCNTs were also determined using the Cartesian coordinate tensor (CCT) transfer technique, thus providing reasonable frequencies of Raman active bands for long tubes consisting of 10 bamboo-units.

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Section: Tangential G-bandsupporting

confidence: 64%

Section: Tangential G-bandmentioning

confidence: 95%

Section: Tangential G-bandmentioning

confidence: 95%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Calculation of Raman parameters of real-size zigzag (n, 0) single-walled carbon nanotubes using finite-size models

Kupka

Stachów

Stobiński

et al. 2016

Phys. Chem. Chem. Phys.

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“…D-band is attributed to carbon atoms with sp 3 -hybridization [50]. RBM peak (A 1g symmetry mode) is used for determination of diameter distribution of carbon nanotubes [57]. And 2D peak is the secondorder D-band.…”

Section: Resultsmentioning

confidence: 99%

Incorporation of epoxy resin and carbon nanotube into silica/siloxane network for improving thermal properties

et al. 2016

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Thermal properties of epoxy resin (E) were improved by its incorporation into silica/siloxane network in the presence of carbon nanotube (CNT). At first, CNT xerogel (CNTX)/E composite was prepared by curing E in the presence of CNTX. Then, E is modified with (3-isocyanatopropyl)triethoxysilane (IE) or tetraethyl orthosilicate (TEOS) oligomer (TE) for its incorporation into a hybrid network of CNT-containing silica/siloxane network. For this purpose, a bifunctional modifier of 1,1 0 -(hexane-1,6-diyl)bis(3-(3-(trimethoxysilyl)propyl)urea) (HDBTMSPU) was synthesized. CNTX was prepared by incorporation of HDBTMSPU-modified CNT (FCNT) into silica/siloxane network by using HDBTMSPU and TEOS. IE (TE), FGO, HDBTMSPU, and TEOS were also used in the preparation of hybrid products. Three types of composites were compared in their thermal degradation temperature and char content. Functionalization of CNT was confirmed by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, Raman, X-ray diffraction (XRD), and thermogravimetric analysis (TGA) results. Xerogel formation was proved by Raman, XRD, and N 2 adsorption and desorption isotherms. TGA results showed that the hybrid of IE, FCNT, and silica/ siloxane network shows higher thermal properties. Char residue is increased 17.54 % by only 4 wt% loading of FCNT in IE resin (IEGX1). Formation of xerogel network around CNT was observed by scanning and transmission electron microscopies.

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Thermal Conductance between <6 nm Single-Walled Carbon Nanotube Bundle and Si Substrate

Al Keyyam,

Rahbar,

Shi

et al. 2024

J. Phys. Chem. C

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Interfacial thermal conductance between a singlewalled carbon nanotube (SWCNT) and substrate is rarely characterized and understood due to substantial challenges in probing the energy transport across such nm-wide contact. Here, we report the interfacial thermal conductance between a <6 nm thick SWCNT bundle and Si substrate. The energy transport stateresolved Raman is employed for the measurement, where the Raman spectrum change under continuous wave (CW) and 20 ns pulsed laser heating is measured for the thermal response of the SWCNT under steady and transient heat conduction sustained by the interfacial thermal conductance. Since no knowledge is needed for laser absorption and temperature rise of the sample, the measurement achieves extreme capability and confidence. For three locations of the SWCNT bundle, the interfacial thermal resistance is measured to be (2.98 ± 0.22) × 10 3 , (3.01 ± 0.23) × 10 3 , and (1.67 ± 0.27) × 10 3 K m W −1 , corresponding to thermal conductance in a range (3.3−6.0) × 10 −4 W m −1 K −1 . Our analysis suggests a loose contact between the SWCNT bundle and the Si substrate, mainly attributed to the obvious nonuniformity of the sample, which was resolved by atomic force microscopy and Raman spectroscopy. For an assumed contact width of ∼1 nm, the interfacial thermal resistance would be of the order of 10 −6 W m −2 K −1 , in line with those reported for mechanically exfoliated graphene and two-dimensional (2D) materials.

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G-band Raman Spectra of Isolated Single Wal Carbon Nanotubes: Diameter and Chiraity Dependence

Cited by 17 publications

References 9 publications

Calculation of Raman parameters of real-size zigzag (n, 0) single-walled carbon nanotubes using finite-size models

Calculation of Raman parameters of real-size zigzag (n, 0) single-walled carbon nanotubes using finite-size models

Incorporation of epoxy resin and carbon nanotube into silica/siloxane network for improving thermal properties

Thermal Conductance between <6 nm Single-Walled Carbon Nanotube Bundle and Si Substrate

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