Wear resistance of nano-polycrystalline diamond with various hexagonal diamond contents

Kurio, A.; Tanaka, Y.; Sumiya, Hitoshi; Irifune, Tetsuo; Shinmei, Toru; Ohfuji, Hiroaki; Kagi, Hiroyuki

doi:10.3103/s1063457612060081

Cited by 13 publications

(8 citation statements)

References 18 publications

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“…This is in reasonable agreement with the experimental study of the polygonization of aligned tubes with a diameter of approximately 17 Å corresponding to (12,12) nanotubes, where rounded-hexagonal cross-sections in bundles were observed without applied pressure [60]. For other SWCNT bundles,such as (8,8),(10,10),(24, 0),and (30, 0), oval-shaped cross sections were observed at ambient pressure [59]. In addition, unlike the metallic isolated armchair SWCNTs, an opening of the band gap resulting from weak intertube interactions and slight nanotube deformation was observed in armchair (4, 4), (5, 5), (6, 6), (7, 7), (9, 9), (10, 10), and (12, 12) SWCNT bundles at ambient pressure [61].…”

Section: Wwwismkievua/stm 44supporting

confidence: 91%

“…For other SWCNT bundles, such as (8,8), (10,10), (24,0), and (30, 0), oval-shaped cross sections were observed at ambient pressure [59]. In addition, unlike the metallic isolated armchair SWCNTs, an opening of the band gap resulting from weak intertube interactions and slight nanotube deformation was observed in armchair (4, 4), (5,5), (6,6), (7,7), (9,9), (10,10), and (12, 12) SWCNT bundles at ambient pressure [61].…”

Section: Theoretical Sectionmentioning

confidence: 99%

“…For example, the compression of graphite can experimentally yield cubic and hexagonal diamonds, as well as a superhard coldcompressed post-graphite phase [5][6][7][8][9][10]. The glass carbon under pressure can transform into a superhard amorphous diamond [11], whereas the compression of C 60 and C 70 fullerenes can produce interesting 1D, 2D, and 3D C 60 and C 70 polymers, as well as other elusive new carbon phases [12][13][14][15][16][17][18][19][20][21][22][23][24][25].…”

Section: Introductionmentioning

confidence: 99%

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High-pressure behaviors of carbon nanotubes

Zhao

Zhou

et al. 2012

J. Superhard Mater.

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High-pressure behaviors of carbon nanotubesIn this paper, we have reviewed the experimental and theoretical studies on pressure-induced polygonization, ovalization, racetrack-shape deformation, and polymerization of carbon nanotubes (CNTs). The corresponding electronic, optical, and mechanical changes accompanying these behaviors have been discussed. The transformations of armchair (n, n) CNT bundles (n = 2, 3, 4, 6, and 8) Keywords: pressure-induced carbon nanotubes, polymerization, novel metastable carbons, electronic and mechanical characteristics. INTRODUCTIONCarbon adopts a wide range of allotropes with unique physical and chemical properties, e.g., graphite, diamond, fullerenes, nanotubes, chaoite, graphene, and amorphous carbon due to its ability to form sp-, sp 2 -, and sp 3 -hybridized bonds. Graphite, the most stable form of carbon at ambient pressure, has a layered and planar structure with the stacked graphene layers coupled by delocalized weak π bonds resulting in conductive and soft nature. Graphene, a recently rising star material, is one-atom-thick planar sheet with a honeycomb crystal lattice like that of graphite. Graphene has the amazing conductivity and strongest tensile strength along the planar layer directions but flexile in the other directions because of the conductive, strong, and flexile sp 2 bonds. Fullerenes and carbon nanotubes (CNTs) represent another two classes of fully sp 2 bonding carbons and are the focus of modern nanoscience and nanotechnology. Structurally, fullerenes are hollow graphitic cage structures composed of nonplanar 5-and 6-membered carbon rings. The smallest fullerene is C 20 [1] . Larger fullerene with increased diameter can also be formed [2,3]. Among them, purified C 60 and C 70 are now commercially available. CNTs can be considered as seamless cylinders formed by rolling single-or multilayer graphene. Different rolling manners yield distinct diametral and chiral CNTs. Given these unique configurations, CNTs possess a wide range of chemical and physical properties, e.g., low density, versatile electronic properties (insulating, semiconducting, Pressure is an effective means to induce the sp 2 -to-sp 3 bond change in carbon, and the produced metastable carbon phases strongly depend on the crystal structure and hybridization scheme of raw carbons, as well as on applied hydrostatic/nonhydrostatic pressure. For example, the compression of graphite can experimentally yield cubic and hexagonal diamonds, as well as a superhard coldcompressed post-graphite phase [5][6][7][8][9][10]. The glass carbon under pressure can transform into a superhard amorphous diamond [11], whereas the compression of C 60 and C 70 fullerenes can produce interesting 1D, 2D, and 3D C 60 and C 70 polymers, as well as other elusive new carbon phases [12][13][14][15][16][17][18][19][20][21][22][23][24][25]. Because a variety of CNT configurations can now be synthesized with a high yield, more interesting pressure-induced structural, electronic, and mechanical changes in CNTs are expected an...

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Section: Wwwismkievua/stm 44supporting

confidence: 91%

Section: Theoretical Sectionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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High-pressure behaviors of carbon nanotubes

Zhao

Zhou

et al. 2012

J. Superhard Mater.

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“…For this reason, we focus on crystalline hexagonal graphite, rather than amorphous graphite, fullerenes or carbon nanotubes. For a review of these carbon materials, please see the other sections in this special issue [19][20][21]. Additionally, there have been several reviews on the high-pressure, high-temperature behavior of carbon [22][23][24][25], however, in this review, we pay special attention to the long-standing controversies on the structural transitions of graphite at high pressures under room temperature conditions as shown through experiments.…”

Section: Introductionmentioning

confidence: 99%

From soft to superhard: Fifty years of experiments on cold-compressed graphite

Wang

Lee

2012

J. Superhard Mater.

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“…The above discussion also applies to differences between other diamondoids and wurtzoids and even nanocrystals and bulk diamond since they all share the same difference in the number of surface H atoms. The increasing interest in laboratory preparation of hexagonal diamond nanoparticles [17,18] can be supported by considering the above properties, which are indispensable in identifying such nanostructures.…”

Section: Theorymentioning

confidence: 99%

Molecular approach to hexagonal and cubic diamond nanocrystals

Abdulsattar¹

2015

Carbon letters

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In the present work, we propose a molecule (C 14 H 14 ) that can be used as a building block of hexagonal diamond-type crystals and nanocrystals, including wurtzite structures. This molecule and its combined blocks are similar to diamondoid molecules that are used as building blocks of cubic diamond crystals and nanocrystals. The hexagonal part of this molecule is included in the C 12 central part of this molecule. This part can be repeated to increase the ratio of hexagonal to cubic diamond and other structures. The calculated energy gap of these molecules (called hereafter wurtzoids) shows the expected trend of gaps that are less than that of cubic diamondoid structures. The calculated binding energy per atom shows that wurtzoids are tighter structures than diamondoids. Distribution of angles and bonds manifest the main differences between hexagonal and cubic diamond-type structures. Charge transfer, infrared, nuclear magnetic resonance and ultraviolet-visible spectra are investigated to identify the main spectroscopic differences between hexagonal and cubic structures at the molecular and nanoscale. Natural bond orbital population analysis shows that the bonding of the present wurtzoids and diamondoids differs from ideal sp 3 bonding. The bonding for carbon valence orbitals is in the range (2s ) for diamantane.

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Wear resistance of nano-polycrystalline diamond with various hexagonal diamond contents

Abstract: Wear resistance of nano-polycrystalline diamond with various hexagonal diamond contents

Cited by 13 publications

References 18 publications

High-pressure behaviors of carbon nanotubes

High-pressure behaviors of carbon nanotubes

From soft to superhard: Fifty years of experiments on cold-compressed graphite

Molecular approach to hexagonal and cubic diamond nanocrystals

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