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Zhang F, Song Z, Hu W, Zhang Y. Identifying of Pure and Defected Ti2C Materials Using Gas Probe Molecules: First Principles Calculations. Chem Asian J 2022; 17:e202200416. [PMID: 35578749 DOI: 10.1002/asia.202200416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 05/12/2022] [Indexed: 11/12/2022]
Abstract
Employing first principles calculations, we systematically investigated the geometrical and electronic structures of pure, titanium defected (DTi) and carbon defected (DC) Ti2C materials. We found the defected Ti2C exhibits stronger metallic property than pure Ti2C due to the enhanced density of Ti-d orbital state near the Fermi level. We then studied the adsorption as well as the infrared spectrum (IR) response of the four kinds of gas molecules (CH4 , NH3 , CO and NO) on pure, DTi and DC Ti2C surfaces. Simulations show that CO and NO molecules are chemically adsorbed on all Ti2C surface with similar adsorption sites. However, CH4 and NH3 molecules would be dissociated on Ti2C surface. Negative values of crystal orbital Hamilton population as well as the PDOS calculations show that the red shift in IR spectra of CO and NO molecules originates from the decreasing bonding strength of probe molecules. The present work provides rich insight for the adsorption and identification for different Ti2C materials.
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Affiliation(s)
- Fengxiang Zhang
- Qilu University of Technology, Shandong Provincial Key Laboratory of Molecular Engineering. School of Chemistry and Chemical Engineering, CHINA
| | - Ziyue Song
- The University of British Columbia, Department of Chemical and Biological Engineering, CANADA
| | - Wei Hu
- Qilu University of Technology, School of Chemistry and Chemical Engineering, 3501 University Road, 250353, Jinan, CHINA
| | - Yujin Zhang
- Qilu University of Technology, School of Electronic and Information Engineering (Department of Physics), CHINA
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2
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Ashraf MA, Liu Z, Peng WX, Najafi M. CH2 and SO Oxidation on Surfaces of Scandium-Doped Nanocages and Cobalt-Doped Nanocages: A DFT Investigation. J STRUCT CHEM+ 2020. [DOI: 10.1134/s0022476620030026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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3
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Fan W, Chen J. Two-state diffusive mobility of slow and fast transport of water in narrow nanochannels. Phys Rev E 2020; 101:010101. [PMID: 32069533 DOI: 10.1103/physreve.101.010101] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Indexed: 11/06/2022]
Abstract
Transport of water in narrow nanochannels as a single-file chain is involved in various biological activities and nanofluidic applications. However, although the consistent dipole orientation of the water molecules is intensively studied, its effect upon the transport behavior is still unknown. In this Rapid Communication, we find two states of slow and fast transport coexist in the single-file water in the presence of channel defects that break the collective dipole orientation. A low diffusive mobility is found for the dipole orientation inconsistent configurations while mobility approximately two times higher is found for the consistent ones. The two-state diffusion process relies on the different hydrogen bond connections, which possess overlapped structures, enabling a spontaneous transition. The slow state is insensitive to the increased defect number while the fast state is reduced accordingly. The two states exhibit different lifetime and temperature dependences that demonstrate a possibility for manipulation. Our result implies the possibility of two-state diffusion process of water in nanofluid phenomena due to the common presence of defects in nanochannels.
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Affiliation(s)
- Wen Fan
- Department of Physics, Fudan University, Shanghai 200433, China.,Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
| | - Jige Chen
- Zhangjiang Laboratory, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China.,Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
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4
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Gavilán-Arriazu EM, Giménez RE, Pinto OA. Structural surface and thermodynamics analysis of nanoparticles with defects. Phys Chem Chem Phys 2020; 22:23148-23157. [DOI: 10.1039/d0cp03348k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this work, we analyze the surface structure and thermodynamics regarding the decoration of nanoparticles with defects, using statistical calculations and Monte Carlo simulations in a complementary way.
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Affiliation(s)
- E. M. Gavilán-Arriazu
- Instituto de Bionanotecnología del NOA (INBIONATEC-CONICET)
- Universidad Nacional de Santiago de Estero
- Santiago del Estero
- Argentina
| | - Rodrigo E. Giménez
- Laboratorio de Biointerfases y Sistemas Biomiméticos, Centro de Investigaciones en Biofisica Aplicada y Alimentos (CIBAAL) (UNSE-CONICET), Villa el Zanjón
- Argentina
| | - O. A. Pinto
- Instituto de Bionanotecnología del NOA (INBIONATEC-CONICET)
- Universidad Nacional de Santiago de Estero
- Santiago del Estero
- Argentina
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5
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Mustonen K, Hussain A, Hofer C, Monazam MRA, Mirzayev R, Elibol K, Laiho P, Mangler C, Jiang H, Susi T, Kauppinen EI, Kotakoski J, Meyer JC. Atomic-Scale Deformations at the Interface of a Mixed-Dimensional van der Waals Heterostructure. ACS NANO 2018; 12:8512-8519. [PMID: 30016070 PMCID: PMC6117744 DOI: 10.1021/acsnano.8b04050] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 07/17/2018] [Indexed: 05/24/2023]
Abstract
Molecular self-assembly due to chemical interactions is the basis of bottom-up nanofabrication, whereas weaker intermolecular forces dominate on the scale of macromolecules. Recent advances in synthesis and characterization have brought increasing attention to two- and mixed-dimensional heterostructures, and it has been recognized that van der Waals (vdW) forces within the structure may have a significant impact on their morphology. Here, we suspend single-walled carbon nanotubes (SWCNTs) on graphene to create a model system for the study of a 1D-2D molecular interface through atomic-resolution scanning transmission electron microscopy observations. When brought into contact, the radial deformation of SWCNTs and the emergence of long-range linear grooves in graphene revealed by the three-dimensional reconstruction of the heterostructure are observed. These topographic features are strain-correlated but show no sensitivity to carbon nanotube helicity, electronic structure, or stacking order. Finally, despite the random deposition of the nanotubes, we show that the competition between strain and vdW forces results in aligned carbon-carbon interfaces spanning hundreds of nanometers.
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Affiliation(s)
- Kimmo Mustonen
- University
of Vienna, Faculty of Physics, 1090 Vienna, Austria
| | - Aqeel Hussain
- Aalto
University School of Science, Department of Applied Physics, P.O. Box
15100, FI-00076 Aalto, Finland
| | - Christoph Hofer
- University
of Vienna, Faculty of Physics, 1090 Vienna, Austria
| | | | - Rasim Mirzayev
- University
of Vienna, Faculty of Physics, 1090 Vienna, Austria
| | - Kenan Elibol
- University
of Vienna, Faculty of Physics, 1090 Vienna, Austria
| | - Patrik Laiho
- Aalto
University School of Science, Department of Applied Physics, P.O. Box
15100, FI-00076 Aalto, Finland
| | - Clemens Mangler
- University
of Vienna, Faculty of Physics, 1090 Vienna, Austria
| | - Hua Jiang
- Aalto
University School of Science, Department of Applied Physics, P.O. Box
15100, FI-00076 Aalto, Finland
| | - Toma Susi
- University
of Vienna, Faculty of Physics, 1090 Vienna, Austria
| | - Esko I. Kauppinen
- Aalto
University School of Science, Department of Applied Physics, P.O. Box
15100, FI-00076 Aalto, Finland
| | - Jani Kotakoski
- University
of Vienna, Faculty of Physics, 1090 Vienna, Austria
| | - Jannik C. Meyer
- University
of Vienna, Faculty of Physics, 1090 Vienna, Austria
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6
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Goclon J, Kozlowska M, Rodziewicz P. Structural, Vibrational and Electronic Properties of Defective Single-Walled Carbon Nanotubes Functionalised with Carboxyl Groups: Theoretical Studies. Chemphyschem 2015; 16:2775-2782. [PMID: 26250867 DOI: 10.1002/cphc.201500364] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Revised: 06/14/2015] [Indexed: 11/10/2022]
Abstract
Covalent sidewall functionalisation of defective zigzag single-walled carbon nanotubes [SWCNTs(10,0)] with COOH groups is investigated by using DFT. Four types of point defects are considered: vacancy (V), divacancy [V2 (5-8-5), V2 (555-777)], adatom (AA) and Stone-Wales (SW). The energetic, structural, electronic and vibrational properties of these systems are analysed. Decreasing reactivity is observed in the following order: AA>V>V2 (555-777)>V2 (5-8-5)>SW. These studies also demonstrate that the position in which a carboxyl group is attached to a defective SWCNT is of primary importance. Saturation of two-coordinate carbon atoms in systems with the vacancy V-7 and with the adatom AA-1(2) is 3.5-4 times more energetically favourable than saturation of three-coordinate carbon atoms for all studied systems. Vibrational analysis for these two systems shows significant redshifts of the ν(CO) stretching vibration of 96 and 123 cm-1 compared to that for carboxylated pristine systems. Detailed electronic-structure analysis of the most stable carboxylated systems is also presented.
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Affiliation(s)
- Jakub Goclon
- Interdisciplinary Center for Molecular Materials (ICMM) and Computer-Chemistry-Center (CCC), Friedrich-Alexander-University Erlangen-Nürnberg, Nägelsbachstrasse 25, 91052 Erlangen (Germany)
| | - Mariana Kozlowska
- Institute of Chemistry, University of Bialystok, Hurtowa 1, 15-399 Bialystok (Poland)
| | - Pawel Rodziewicz
- Institute of Chemistry, University of Bialystok, Hurtowa 1, 15-399 Bialystok (Poland)
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7
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Theoretical investigation on the healing mechanism of divacancy defect in CNT growth by C2H2 and C2H4. J Mol Model 2014; 20:2125. [DOI: 10.1007/s00894-014-2125-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Accepted: 12/20/2013] [Indexed: 11/25/2022]
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8
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Carbon Doping of Defect Sites in Stone–Wales Defective Boron-nitride Nanotubes: A Density Functional Theory Study. J CLUST SCI 2013. [DOI: 10.1007/s10876-013-0584-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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9
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Nishino T, Kanata S, Umezawa Y. Selective visualization of point defects in carbon nanotubes at the atomic scale by an electron-donating molecular tip. Chem Commun (Camb) 2011; 47:7467-9. [PMID: 21629907 DOI: 10.1039/c1cc12045j] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- Tomoaki Nishino
- Nanoscience and Nanotechnology Research Center, Research Organization for the 21st Century, Osaka Prefecture University, Sakai, Osaka 599-8570, Japan.
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10
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Xiao B, Zhao JX, Ding YH, Sun CC. Theoretical Investigation of the Interaction between Carbon Monoxide and Carbon Nanotubes with Single-Vacancy Defects. Chemphyschem 2010; 11:3505-10. [DOI: 10.1002/cphc.201000325] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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11
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Kulathunga DDTK, Ang KK, Reddy JN. Molecular dynamics analysis on buckling of defective carbon nanotubes. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2010; 22:345301. [PMID: 21403253 DOI: 10.1088/0953-8984/22/34/345301] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Owing to their remarkable mechanical properties, carbon nanotubes have been employed in many diverse areas of applications. However, similar to any of the many man-made materials used today, carbon nanotubes (CNTs) are also susceptible to various kinds of defects. Understanding the effect of defects on the mechanical properties and behavior of CNTs is essential in the design of nanotube-based devices and composites. It has been found in various past studies that these defects can considerably affect the tensile strength and fracture of CNTs. Comprehensive studies on the effect of defects on the buckling and vibration of nanotubes is however lacking in the literature. In this paper, the effects of various configurations of atomic vacancy defects, on axial buckling of single-walled carbon nanotubes (SWCNTs), in different thermal environments, is investigated using molecular dynamics simulations (MDS), based on a COMPASS force field. Our findings revealed that even a single missing atom can cause a significant reduction in the critical buckling strain and load of SWCNTs. In general, increasing the number of missing atoms, asymmetry of vacancy configurations and asymmetric distribution of vacancy clusters seemed to lead to higher deterioration in buckling properties. Further, SWCNTs with a single vacancy cluster, compared to SWCNTs with two or more vacancy clusters having the same number of missing atoms, appeared to cause higher deterioration of buckling properties. However, exceptions from the above mentioned trends could be expected due to chemical instabilities of defects. Temperature appeared to have less effect on defective CNTs compared to pristine CNTs.
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Affiliation(s)
- D D T K Kulathunga
- Department of Civil Engineering, National University of Singapore, Singapore
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12
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Cole MW, Crespi VH, Dresselhaus MS, Dresselhaus G, Fischer JE, Gutierrez HR, Kojima K, Mahan GD, Rao AM, Sofo JO, Tachibana M, Wako K, Xiong Q. Structural, electronic, optical and vibrational properties of nanoscale carbons and nanowires: a colloquial review. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2010; 22:334201. [PMID: 21386491 DOI: 10.1088/0953-8984/22/33/334201] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
This review addresses the field of nanoscience as viewed through the lens of the scientific career of Peter Eklund, thus with a special focus on nanocarbons and nanowires. Peter brought to his research an intense focus, imagination, tenacity, breadth and ingenuity rarely seen in modern science. His goal was to capture the essential physics of natural phenomena. This attitude also guides our writing: we focus on basic principles, without sacrificing accuracy, while hoping to convey an enthusiasm for the science commensurate with Peter's. The term 'colloquial review' is intended to capture this style of presentation. The diverse phenomena of condensed matter physics involve electrons, phonons and the structures within which excitations reside. The 'nano' regime presents particularly interesting and challenging science. Finite size effects play a key role, exemplified by the discrete electronic and phonon spectra of C(60) and other fullerenes. The beauty of such molecules (as well as nanotubes and graphene) is reflected by the theoretical principles that govern their behavior. As to the challenge, 'nano' requires special care in materials preparation and treatment, since the surface-to-volume ratio is so high; they also often present difficulties of acquiring an experimental signal, since the samples can be quite small. All of the atoms participate in the various phenomena, without any genuinely 'bulk' properties. Peter was a master of overcoming such challenges. The primary activity of Eklund's research was to measure and understand the vibrations of atoms in carbon materials. Raman spectroscopy was very dear to Peter. He published several papers on the theory of phonons (Eklund et al 1995a Carbon 33 959-72, Eklund et al 1995b Thin Solid Films 257 211-32, Eklund et al 1992 J. Phys. Chem. Solids 53 1391-413, Dresselhaus and Eklund 2000 Adv. Phys. 49 705-814) and many more papers on measuring phonons (Pimenta et al 1998b Phys. Rev. B 58 16016-9, Rao et al 1997a Nature 338 257-9, Rao et al 1997b Phys. Rev. B 55 4766-73, Rao et al 1997c Science 275 187-91, Rao et al 1998 Thin Solid Films 331 141-7). His careful sample treatment and detailed Raman analysis contributed greatly to the elucidation of photochemical polymerization of solid C(60) (Rao et al 1993b Science 259 955-7). He developed Raman spectroscopy as a standard tool for gauging the diameter of a single-walled carbon nanotube (Bandow et al 1998 Phys. Rev. Lett. 80 3779-82), distinguishing metallic versus semiconducting single-walled carbon nanotubes, (Pimenta et al 1998a J. Mater. Res. 13 2396-404) and measuring the number of graphene layers in a peeled flake of graphite (Gupta et al 2006 Nano Lett. 6 2667-73). For these and other ground breaking contributions to carbon science he received the Graffin Lecture award from the American Carbon Society in 2005, and the Japan Carbon Prize in 2008. As a material, graphite has come full circle. The 1970s renaissance in the science of graphite intercalation compounds paved the way for a later explosion in nanocarbon research by illuminating many beautiful fundamental phenomena, subsequently rediscovered in other forms of nanocarbon. In 1985, Smalley, Kroto, Curl, Heath and O'Brien discovered carbon cage molecules called fullerenes in the soot ablated from a rotating graphite target (Kroto et al 1985 Nature 318 162-3). At that time, Peter's research was focused mainly on the oxide-based high-temperature superconductors. He switched to fullerene research soon after the discovery that an electric arc can prepare fullerenes in bulk quantities (Haufler et al 1990 J. Phys. Chem. 94 8634-6). Later fullerene research spawned nanotubes, and nanotubes spawned a newly exploding research effort on single-layer graphene. Graphene has hence evolved from an oversimplified model of graphite (Wallace 1947 Phys. Rev. 71 622-34) to a new member of the nanocarbon family exhibiting extraordinary electronic properties. Eklund's career spans this 35-year odyssey.
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Affiliation(s)
- Milton W Cole
- Department of Physics, Penn State University, 104 Davey Lab MB123, University Park, PA 16802-6300, USA.
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NISHINO T, UMEZAWA Y. Recognition of Chemical Identity of Organic Adsorbates on Solid Surfaces at the Nanoscale by Molecular STM Tips. ANAL SCI 2010; 26:1023-32. [DOI: 10.2116/analsci.26.1023] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Tomoaki NISHINO
- Nanoscience and Nanotechnology Research Center, Research Organization for the 21st Century, Osaka Prefecture University
- PRESTO, Japan Science and Technology Agency
| | - Yoshio UMEZAWA
- Research Institute of Pharmaceutical Sciences, Musashino University
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14
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Chapter 1 Nanotubes: an experimental overview. ACTA ACUST UNITED AC 2008. [DOI: 10.1016/s1572-0934(08)00001-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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15
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Barinov A, Ustünel H, Fabris S, Gregoratti L, Aballe L, Dudin P, Baroni S, Kiskinova M. Defect-controlled transport properties of metallic atoms along carbon nanotube surfaces. PHYSICAL REVIEW LETTERS 2007; 99:046803. [PMID: 17678388 DOI: 10.1103/physrevlett.99.046803] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2007] [Indexed: 05/16/2023]
Abstract
The diffusion mechanism of indium atoms along multiwalled carbon nanotubes is studied by means of photoemission spectromicroscopy and density functional theory calculations. The unusually high activation temperature for diffusion (approximately 700 K), the complex C 1s and In 3d5/2 spectra, and the calculated adsorption energies and diffusion barriers suggest that the indium transport is controlled by the concentration of defects in the C network and proceeds via hopping of indium adatoms between C vacancies.
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Affiliation(s)
- Alexei Barinov
- Sincrotrone Trieste, Area Science Park, I-34012 Basovizza, Trieste, Italy
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Yang SH, Shin WH, Kang JK. Ni adsorption on Stone-Wales defect sites in single-wall carbon nanotubes. J Chem Phys 2006; 125:084705. [PMID: 16965037 DOI: 10.1063/1.2337293] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Ni adsorption on Stone-Wales defect sites in (10,0) zigzag and (5,5) armchair single-wall carbon nanotubes was studied using the density functional theory. The stable adsorption sites and their binding energies on different Stone-Wales defect types were analyzed and compared to those on perfect side walls. It was determined that the sites formed via fusions of 7-7 and 6-7 rings are the most exothermic in the cases of (10,0) and (5,5) defective tubes. In addition C-C bonds associated with Stone-Wales defects are more reactive than the case for a perfect hexagon, thus enhancing the stability of the Ni adsorption. Moreover, the Ni adsorption was found to show a noticeable relationship to the orientation of the Stone-Wales defects with respect to the tube axis. The nature of the Ni adsorption on Stone-Wales defects that have the similar orientation is identical, in spite of the different chiralities.
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Affiliation(s)
- Seong Ho Yang
- Laboratory of Nano Materials Simulation and Fabrication, Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea
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Yang SH, Shin WH, Lee JW, Kim SY, Woo SI, Kang JK. Interaction of a Transition Metal Atom with Intrinsic Defects in Single-Walled Carbon Nanotubes. J Phys Chem B 2006; 110:13941-6. [PMID: 16836345 DOI: 10.1021/jp061895q] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Interaction of a transition metal atom with defects in single-walled carbon nanotubes (SWNTs) were investigated through density functional theory calculations. For three kinds of intrinsic defects (single vacancies, double vacancies and Stone-Wales defects) in (5,5) armchair and (10,0) zigzag SWNTs, stable configurations were analyzed. The orientation of the specific bonds of the defects is related to the most stable configuration among several possible configurations. The stable adsorption sites and binding energies of a Ni atom on three intrinsic defects were calculated and compared to those on perfect side walls. All defects enhance Ni adsorption, and the single vacancy shows the most exothermic binding. These results shed light on the nature of the interaction of the transition metal with defects in SWNT, an important topic to the many aspects of carbon nanotubes interacting with transition metals. Particularly, this is useful for the fabrication of nanosized transition metal particles supported on carbon nanotubes.
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Affiliation(s)
- Seong Ho Yang
- Nano Materials Simulation and Fabrication Laboratory, Department of Materials Science and Engineering, KAIST, 373-1, Guseong-dong, Yuseong-gu, Daejeon 305-701, Korea
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18
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Fan Y, Goldsmith BR, Collins PG. Identifying and counting point defects in carbon nanotubes. NATURE MATERIALS 2005; 4:906-11. [PMID: 16267574 DOI: 10.1038/nmat1516] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2005] [Accepted: 09/15/2005] [Indexed: 05/05/2023]
Abstract
The prevailing conception of carbon nanotubes and particularly single-walled carbon nanotubes (SWNTs) continues to be one of perfectly crystalline wires. Here, we demonstrate a selective electrochemical method that labels point defects and makes them easily visible for quantitative analysis. High-quality SWNTs are confirmed to contain one defect per 4 microm on average, with a distribution weighted towards areas of SWNT curvature. Although this defect density compares favourably to high-quality, silicon single-crystals, the presence of a single defect can have tremendous electronic effects in one-dimensional conductors such as SWNTs. We demonstrate a one-to-one correspondence between chemically active point defects and sites of local electronic sensitivity in SWNT circuits, confirming the expectation that individual defects may be critical to understanding and controlling variability, noise and chemical sensitivity in SWNT electronic devices. By varying the SWNT synthesis technique, we further show that the defect spacing can be varied over orders of magnitude. The ability to detect and analyse point defects, especially at very low concentrations, indicates the promise of this technique for quantitative process analysis, especially in nanoelectronics development.
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Affiliation(s)
- Yuwei Fan
- Department of Physics and Astronomy, University of California at Irvine, Irvine, California 92697-4576, USA
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Lee S, Kim G, Kim H, Choi BY, Lee J, Jeong BW, Ihm J, Kuk Y, Kahng SJ. Paired gap states in a semiconducting carbon nanotube: deep and shallow levels. PHYSICAL REVIEW LETTERS 2005; 95:166402. [PMID: 16241824 DOI: 10.1103/physrevlett.95.166402] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2005] [Indexed: 05/05/2023]
Abstract
Several paired, localized gap states were observed in semiconducting single-wall carbon nanotubes using spatially resolved scanning tunneling spectroscopy. A pair of gap states is found far from the band edges, forming deep levels, while the other pair is located near the band edges, forming shallow levels. With the help of a first-principles study, the former is explained by a vacancy-adatom complex while the latter is explained by a pentagon-heptagon structure. Our experimental observation indicates that the presence of the gap states provides a means to perform local band-gap engineering as well as doping without impurity substitution.
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Affiliation(s)
- Sungjun Lee
- School of Physics, Seoul National University, Korea
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20
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