| 11. |
- Kabir, Mohammad, 1974, et al.
(författare)
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Fabrication of individual, vertically aligned carbon nanofibres on metal substrates from prefabricated catalyst dots
- 2006
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Ingår i: Nanotechnology. - : IOP Publishing. - 0957-4484 .- 1361-6528. ; 17:3, s. 790-794
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Tidskriftsartikel (refereegranskat)abstract
- Carbon nanofibres (CNFs) of controlled diameter and length were grown on different metal substrates using plasma-enhanced chemical vapour deposition (PECVD). The diameter control of catalyst dots (and hence CNF diameter) was obtained by using the shot modulation technique in electron beam lithography. Catalyst dots of different sizes within arrays of different pitch were prepared and the dependence of the growth of vertically aligned CNFs on these parameters was studied for different metal underlayers. Good quality vertically aligned CNFs with a narrow length distribution were grown on Mo and W substrates. The structures grown on Nb substrates were significantly shorter for identical growth conditions and showed a lower nucleation rate. We demonstrate that through the shot modulation technique it is possible to control the diameter variation of CNFs from a single design geometry for the catalyst deposition. Individual VACNFs can be grown down to a pitch within the range 100–500 nm.
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| 12. |
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| 13. |
- Kabir, Mohammad, 1974, et al.
(författare)
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Plasma-enhanced chemical vapour deposition growth of carbon nanotubes on different metal underlayers
- 2005
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Ingår i: Nanotechnology. - : IOP Publishing. - 0957-4484 .- 1361-6528. ; 16, s. 458-466
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Tidskriftsartikel (refereegranskat)abstract
- One important requirement for future applications of carbon nanotube electronic devices is the ability to controllably grow carbon nanotubes on metal electrodes. Here we show that it is possible to grow small diameter (<10 nm) vertically aligned carbon nanotubes on different metal underlayers using plasma-enhanced chemical vapour deposition. A crucial component is the insertion of a thin silicon layer between the metal and the catalyst particle. The electrical integrity of the metal electrode layer after plasma treatment and the quality of the metals as interconnects are also investigated.
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| 14. |
- Lassesson, Andreas, 1976, et al.
(författare)
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Formation of small lanthanum-carbide ions from laser induced fragmentation of La@C-82
- 2003
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Ingår i: Journal of Chemical Physics. - : AIP Publishing. - 1089-7690 .- 0021-9606. ; 119:11, s. 5591-5600
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Tidskriftsartikel (refereegranskat)abstract
- The fragmentation behavior of the endohedral metallofullerene La@C-82 was studied using gas phase time-of-flight mass spectrometry. The results were compared with the fragmentation of C-60. When the metallofullerene was excited by a 337 nm ns laser, small lanthanum-carbide fragments LaCn+, n=0-6, were detected. A simple statistical maximum entropy model was used to simulate the excitation energy dependence of the loss of the LaCn+ molecules as well as C-2 evaporation to form smaller metallofullerenes. By comparing experimental ion intensities with the model, the appearance energies of LaCn+, n=0-6, were found to lie above 65 eV. The lanthanum-carbide fragments ejected from La@C-82 decrease in size with increasing internal energy. The ejection of La+ and LaC2+ is preferred at the expense of larger fragments such as LaC4+ and metallofullerenes at the higher excitation. (C) 2003 American Institute of Physics.
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| 15. |
- Lassesson, Andreas, 1976, et al.
(författare)
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Investigations into the fragmentation and ionization of highly excited La@C-82
- 2002
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Ingår i: Journal of Chemical Physics. - : AIP Publishing. - 1089-7690 .- 0021-9606. ; 117:21, s. 9811-9817
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Tidskriftsartikel (refereegranskat)abstract
- We report the first measurements of delayed ionization of the metallofullerene La@C-82. When highly excited in laser desorption, La@C-82 was found to ionize over several microseconds. The rate of delayed ionization of La@C-82 was compared to C-60 under the same extraction conditions, and found to be significantly different. A theoretical model was used for the fitting of the ion signal of the two fullerenes. The metallofullerene results can be fitted well over a time window
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| 16. |
- Lee, SangWook, et al.
(författare)
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A three-terminal carbon nanorelay
- 2004
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Ingår i: Nano letters. - : American Chemical Society (ACS). - 1530-6984 .- 1530-6992. ; 4:10, s. 2027-2030
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Tidskriftsartikel (refereegranskat)abstract
- Three-terminal nanorelay structures were fabricated with multiwall carbon nanotubes (MWNTs). The nanotube relays were deflected by applying a gate voltage until contact (mechanical and/or electrical) was made with a drain electrode, thus closing the circuit. It was possible to achieve multiple switching cycles, showing that carbon nanotubes are suitable and practical systems for developing nanoelectromechanical devices of this kind.
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| 17. |
- Lindahl, Niklas, 1981, et al.
(författare)
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Determination of the Bending Rigidity of Graphene via Electrostatic Actuation of Buckled Membranes
- 2012
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Ingår i: Nano Letters. - : American Chemical Society (ACS). - 1530-6984 .- 1530-6992. ; 12:7, s. 3526-3531
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Tidskriftsartikel (refereegranskat)abstract
- Classical continuum mechanics is used extensively to predict the properties of nanoscale materials such as graphene. The bending rigidity, kappa, is an important parameter that is used, for example, to predict the performance of graphene nanoelectromechanical devices and also ripple formation. Despite its importance, there is a large spread in the theoretical predictions of kappa for few-layer graphene. We have used the snap-through behavior of convex buckled graphene membranes under the application of electrostatic pressure to determine experimentally values of kappa for double-layer graphene membranes. We demonstrate how to prepare convex-buckled suspended graphene ribbons and fully clamped suspended membranes and show how the determination of the curvature of the membranes and the critical snap-through voltage, using AFM, allows us to extract kappa. The bending rigidity of bilayer graphene membranes under ambient conditions was determined to be 35.5(-15.0)(+20.0) eV. Monolayers are shown to have significantly lower kappa than bilayers.
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| 18. |
- Mattsson, M, et al.
(författare)
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Dielectrophoresis-induced separation of metallic and semiconducting SWNT in a continuous flow microfluidic system
- 2007
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Ingår i: Journal of Nanotechnology and Nanoscience. - : American Scientific Publishers. - 1533-4880. ; 7, s. 3431-3435
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Tidskriftsartikel (refereegranskat)abstract
- The AC dielectrophoresis-induced separation of metallic and semiconducting single-wall carbon nanotubes has been carried out in a continuous flow microfluidic system with isolated electrodes. The separation has been studied for single-wall carbon nanotube aqueous suspensions with ionic (sodium dodecylsulphate) and non-ionic (TritonX-100) surfactants. The efficiency of separation has been determined with the help of resonant Raman spectroscopy using various excitation energies. The prototype microfluidic cell presently shows somewhat inferior separation efficiency with respect to static dielectrophoretic filtering on arrays of microelectrodes but has potential for improvements. Factors influencing the separation efficiency and scaling up of the process are discussed.
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| 19. |
- Morjan, Raluca Elena, 1976, et al.
(författare)
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High growth rates and wall decoration of carbon nanotubes grown by plasma-enhanced chemical vapour deposition
- 2004
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Ingår i: Chemical Physics Letters. - : Elsevier BV. - 0009-2614. ; 383/4, s. 385-390
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- DC plasma-enhanced chemical vapour deposition (PECVD) was used to grow films of aligned carbon nanotubes on a silicon wafer using Fe as catalyst and a C2H2/H2 gas mixture. The films were of high quality and showed an exceptionally high growth rate compared with other plasma growth techniques. For long growth times, the upper parts of the nanotubes developed additional outer graphite flakes. The onset of the ‘tube decoration’ correlates with a decrease in linear growth rate and can be related to the gradient of plasma parameters in the cathode sheath.
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| 20. |
- Morjan, Raluca Elena, 1976, et al.
(författare)
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Selective growth of individual multiwalled carbon nanotubes
- 2004
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Ingår i: Current Applied Physics. - : Elsevier BV. - 1567-1739. ; 4:6, s. 591-594
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Tidskriftsartikel (refereegranskat)abstract
- Growth of individual, vertically aligned multiwalled carbon nanotubes (VACNT) on patterned Si wafers using dc plasma-enhanced CVD is described. The selective growth of individual VACNT within larger holes etched in Si is demonstrated for the first time.
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