Search Results - (Author, Cooperation:P. M. Ajayan)
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1Latest Papers from Table of Contents or Articles in PressD. Sarkar ; X. Xie ; W. Liu ; W. Cao ; J. Kang ; Y. Gong ; S. Kraemer ; P. M. Ajayan ; K. Banerjee
Nature Publishing Group (NPG)
Published 2015Staff ViewPublication Date: 2015-10-04Publisher: Nature Publishing Group (NPG)Print ISSN: 0028-0836Electronic ISSN: 1476-4687Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsPublished by: -
2Latest Papers from Table of Contents or Articles in PressKochat, V., Samanta, A., Zhang, Y., Bhowmick, S., Manimunda, P., Asif, S. A. S., Stender, A. S., Vajtai, R., Singh, A. K., Tiwary, C. S., Ajayan, P. M.
American Association for the Advancement of Science (AAAS)
Published 2018Staff ViewPublication Date: 2018-03-12Publisher: American Association for the Advancement of Science (AAAS)Electronic ISSN: 2375-2548Topics: Natural Sciences in GeneralPublished by: -
3Latest Papers from Table of Contents or Articles in PressTsai, H., Asadpour, R., Blancon, J.-C., Stoumpos, C. C., Durand, O., Strzalka, J. W., Chen, B., Verduzco, R., Ajayan, P. M., Tretiak, S., Even, J., Alam, M. A., Kanatzidis, M. G., Nie, W., Mohite, A. D.
American Association for the Advancement of Science (AAAS)
Published 2018Staff ViewPublication Date: 2018-04-06Publisher: American Association for the Advancement of Science (AAAS)Print ISSN: 0036-8075Electronic ISSN: 1095-9203Topics: BiologyChemistry and PharmacologyGeosciencesComputer ScienceMedicineNatural Sciences in GeneralPhysicsKeywords: Physics, Applied, Materials SciencePublished by: -
4Latest Papers from Table of Contents or Articles in PressKinloch, I. A., Suhr, J., Lou, J., Young, R. J., Ajayan, P. M.
American Association for the Advancement of Science (AAAS)
Published 2018Staff ViewPublication Date: 2018-11-02Publisher: American Association for the Advancement of Science (AAAS)Print ISSN: 0036-8075Electronic ISSN: 1095-9203Topics: BiologyChemistry and PharmacologyGeosciencesComputer ScienceMedicineNatural Sciences in GeneralPhysicsPublished by: -
5Articles: DFG German National LicensesStaff View
ISSN: 1089-7550Source: AIP Digital ArchiveTopics: PhysicsNotes: Here we present experimental results, using high-resolution electron microscopy and real time video recording, on the liquid-like coalescence of small gold particles supported on silica. We report that particles that are few nanometers in size, and decoupled from substrate interactions, coalesce extremely fast, in fractions of a second. When the particles are properly supported on a substrate, coalescence is orders of magnitude slower, depending on the particle size, and influenced by the diffusion of atoms on the substrate surface. Necks are seen to develop distinctly during coalescence only for particles above certain size.Type of Medium: Electronic ResourceURL: -
6Articles: DFG German National LicensesSchadler, L. S. ; Giannaris, S. C. ; Ajayan, P. M.
Woodbury, NY : American Institute of Physics (AIP)
Published 1998Staff ViewISSN: 1077-3118Source: AIP Digital ArchiveTopics: PhysicsNotes: The mechanical behavior of multiwalled carbon nanotube/epoxy composites was studied in both tension and compression. It was found that the compression modulus is higher than the tensile modulus, indicating that load transfer to the nanotubes in the composite is much higher in compression. In addition, it was found that the Raman peak position, indicating the strain in the carbon bonds under loading, shifts significantly under compression but not in tension. It is proposed that during load transfer to multiwalled nanotubes, only the outer layers are stressed in tension whereas all the layers respond in compression. © 1998 American Institute of Physics.Type of Medium: Electronic ResourceURL: -
7Articles: DFG German National LicensesCao, Anyuan ; Wei, Bingqing ; Jung, Y. ; Vajtai, Robert ; Ajayan, P. M. ; Ramanath, G.
Woodbury, NY : American Institute of Physics (AIP)
Published 2002Staff ViewISSN: 1077-3118Source: AIP Digital ArchiveTopics: PhysicsNotes: We demonstrate a two-step chemical vapor deposition process to obtain carbon nanotube (CNT) networks using aligned nanotube films themselves as growth templates. Track patterns of exposed silica created in CNT films grown in the first step serve as macroscopic templates for growing CNT stripes in the second step. The nanotubes in both the template and the stripes are vertically aligned. The CNT templates can be selectively removed while retaining the network of CNT stripes grown among them in the predefined patterns. Two-step processes such as described here will be of interest for creating multilayered CNT architectures through pattern transfer and growth sequences. © 2002 American Institute of Physics.Type of Medium: Electronic ResourceURL: -
8Articles: DFG German National LicensesZhang, Z. J. ; Wei, B. Q. ; Ramanath, G. ; Ajayan, P. M.
Woodbury, NY : American Institute of Physics (AIP)
Published 2000Staff ViewISSN: 1077-3118Source: AIP Digital ArchiveTopics: PhysicsNotes: We report highly substrate-site selective growth of carbon nanotubes by chemical vapor deposition from precursors of ferrocene and xylene mixtures. The technique allows us to grow well-aligned multiwalled carbon nanotubes preferentially on the SiO2 regions of patterned SiO2/Si substrates prepared by conventional lithography. This eliminates the catalyst predeposition step in the fabrication process. This simple approach may also be applied to build large-scale networks of organized nanotubes on planar substrates. © 2000 American Institute of Physics.Type of Medium: Electronic ResourceURL: -
9Articles: DFG German National LicensesWei, B. Q. ; Vajtai, R. ; Ajayan, P. M.
Woodbury, NY : American Institute of Physics (AIP)
Published 2001Staff ViewISSN: 1077-3118Source: AIP Digital ArchiveTopics: PhysicsNotes: The current-carrying capacity and reliability studies of multiwalled carbon nanotubes under high current densities (〉109 A/cm2) show that no observable failure in the nanotube structure and no measurable change in the resistance are detected at temperatures up to 250 °C and for time scales up to 2 weeks. Our results suggest that nanotubes are potential candidates as interconnects in future large-scale integrated nanoelectronic devices. © 2001 American Institute of Physics.Type of Medium: Electronic ResourceURL: -
10Articles: DFG German National LicensesZhang, Z. J. ; Ajayan, P. M. ; Ramanath, G.
Woodbury, NY : American Institute of Physics (AIP)
Published 2001Staff ViewISSN: 1077-3118Source: AIP Digital ArchiveTopics: PhysicsNotes: We report the synthesis of carbon-reinforced silica fibers by methane exposure of metallocene-treated oxidized-Si(001) substrates at 1100 °C. The SiO2 cap layer transforms into silica fibers reinforced by glassy carbon in the core during methane exposure. High-resolution electron microscopy and spatially resolved spectroscopy measurements of the fibers reveal an amorphous structure without a hollow, and domains of glassy carbon embedded at the fiber core. The carbon-reinforced fibers are optically transparent and have an optical band gap of (similar, equals)3.1 eV. These fibers are organized in radial patterns that vary for different metallocene species. On nickelocene-treated substrates, the fibers originate from the circumference of the circular templates and grow outwards, forming radial patterns. On ferrocene-treated substrates, randomly oriented fibers grow within as well as slightly outside the perimeter of the templates, forming wreath-like patterns. Aligned growth of such fibers could be useful for fabricating optoelectronics devices and reinforced composites. © 2001 American Institute of Physics.Type of Medium: Electronic ResourceURL: -
11Articles: DFG German National LicensesWei, Bingqing ; Zhang, Z. J. ; Ramanath, G. ; Ajayan, P. M.
Woodbury, NY : American Institute of Physics (AIP)
Published 2000Staff ViewISSN: 1077-3118Source: AIP Digital ArchiveTopics: PhysicsNotes: The fabrication of three-dimensional networks of carbon nanotubes with controlled orientation will be essential for building large-scale functional devices integrated with microelectronics circuits. We describe here our recent work on the controlled synthesis of vertically aligned carbon-nanotube patterns, grown under patterned metal layers on Si substrates by combining chemical-vapor deposition and conventional lithography. We show that metal patterns are lifted up by vertically aligned nanotubes during growth. This lift-up growth links the thin-film metal patterns and the Si substrate via nanotube assemblies, giving the possibility of creating nanotube architectures in three dimensions. The possible scenarios of the growth of aligned nanotube films leading to the lift up of the metal films are discussed. © 2000 American Institute of Physics.Type of Medium: Electronic ResourceURL: -
12Articles: DFG German National LicensesWei, B. Q. ; Vajtai, R. ; Jung, Y. ; Ward, J. ; Zhang, R. ; Ramanath, G. ; Ajayan, P. M.
[s.l.] : Nature Publishing Group
Published 2002Staff ViewISSN: 1476-4687Source: Nature Archives 1869 - 2009Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsNotes: [Auszug] Nanoscale structures need to be arranged into well-defined configurations in order to build integrated systems. Here we use a chemical-vapour deposition method with gas-phase catalyst delivery to direct the assembly of carbon nanotubes in a variety of predetermined orientations onto ...Type of Medium: Electronic ResourceURL: -
13Articles: DFG German National LicensesStaff View
ISSN: 1476-4687Source: Nature Archives 1869 - 2009Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsNotes: [Auszug] We found recently that electron-irradiation-induced damage to carbon onions is annealed in situ at high specimen temperatures3. This enables us to generate and observe onion-like particles with essentially undistorted shells. We used a high-voltage transmission electron microscope (Jeol ARM 1250) ...Type of Medium: Electronic ResourceURL: -
14Articles: DFG German National LicensesAjayan, P. M. ; Nugent, J. M. ; Siegel, R. W. ; Wei, B. ; Kohler-Redlich, Ph.
[s.l.] : Macmillan Magazines Ltd.
Published 2000Staff ViewISSN: 1476-4687Source: Nature Archives 1869 - 2009Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsNotes: [Auszug] The complex deposition and growth of graphitic carbon has come up with several surprises in recent years, including the growth of fullerenes and carbon nanotubes. Here we describe the spectacular growth of micron-sized tree-like carbon structures produced by chemical vapour deposition of ...Type of Medium: Electronic ResourceURL: -
15Articles: DFG German National LicensesEbbesen, T. W. ; Ajayan, P. M. ; Hiura, H. ; Tanigaki, K.
[s.l.] : Nature Publishing Group
Published 1994Staff ViewISSN: 1476-4687Source: Nature Archives 1869 - 2009Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsNotes: [Auszug] SIR - Carbon nanotubes can now be produced in large quantities, either as multi-shell112 or as single-layer3'4 tubes. But together with the growth of the tubu-lar material, other carbonaceous mat-erials are always formed and their pre-sence has hampered the accurate charac-terization of the bulk ...Type of Medium: Electronic ResourceURL: -
16Articles: DFG German National LicensesStaff View
ISSN: 1476-4687Source: Nature Archives 1869 - 2009Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsNotes: [Auszug] We synthesized carbon nanotubes as bulk cylindrical deposits, according to the method of ref. 2. The core of the deposit, which contains the nanotubes, was sonicated in ethanol and a drop of the solution was dried over a perforated carbon grid. Lead particles were then deposited onto the tubes ...Type of Medium: Electronic ResourceURL: -
17Articles: DFG German National LicensesAjayan, P. M. ; Ebbesen, T. W. ; Ichihashi, T. ; Iijima, S. ; Tanigaki, K. ; Hiura, H.
[s.l.] : Nature Publishing Group
Published 1993Staff ViewISSN: 1476-4687Source: Nature Archives 1869 - 2009Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsNotes: [Auszug] The experiments were done with carbon nanotubes produced by the arc-discharge method described previously2. Weighed amounts of the carbon nanotube samples were heated in air in an open quartz vessel. The samples started to show substantial loss of weight once they were heated above 700 ...Type of Medium: Electronic ResourceURL: -
18Articles: DFG German National LicensesEvidence for sinking of small particles into substrates and implications for heterogeneous catalysisStaff View
ISSN: 1476-4687Source: Nature Archives 1869 - 2009Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsNotes: [Auszug] The structure of a small particle may not resemble the structure of the same bulk material because the large surface-to-volume ratio gives rise to a large surface-energy contribution to the total energy. The shape of a small particle is highly surface-energy-dependent and can be estimated by the ...Type of Medium: Electronic ResourceURL: -
19Articles: DFG German National LicensesStaff View
ISSN: 1476-4687Source: Nature Archives 1869 - 2009Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsNotes: [Auszug] SIR - The discovery and synthesis of Ceo molecules have led to an explosion of interest in the family of carbon structures and compounds. We have recently reported the discovery of carbon nano tubes', consisting of concentric sheets of carbon hexagons arranged in a helical manner, but with the ends ...Type of Medium: Electronic ResourceURL: -
20Articles: DFG German National LicensesStaff View
ISSN: 1476-4687Source: Nature Archives 1869 - 2009Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsNotes: [Auszug] The carbon arc experiments are done in a reaction vessel through which an inert gas (He, Ar and so on) flows at a controlled pressure. We apply a potential of ~ 18 V, either a.c. or d.c., between two graphite rods (one 6 mm and the other 9 mm in diameter) in the vessel. As the rods are ...Type of Medium: Electronic ResourceURL: