| 1. |
- Chernogorova, Olga P., et al.
(författare)
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Indentation behaviour of superelastic hard carbon
- 2016
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Ingår i: Philosophical Magazine. - : Informa UK Limited. - 1478-6435 .- 1478-6443. ; 96:32-34, s. 3451-3460
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Tidskriftsartikel (refereegranskat)abstract
- Superelastic hard carbon particles widely varying in structure andproperties have been studied by instrumented microindentationtechnique. The carbon particles up to 200 μm in size were producedby fullerene collapse upon high-pressure high-temperature treatmentof metal–fullerene powder mixture with simultaneous sintering ofmetal matrix composite materials (CM) reinforced by the particles.The structure and properties of the carbon particles were controlledby changing synthesis parameters and the state (composition andstructure) of the parent fullerite crystals. The specific features of theinstrumented indentation behaviour of the particles were studied asa function of their hardness. Mechanical properties of the particlestested at loads of up to 1970 mN exhibit an indentation size effect,which becomes more pronounced with increasing hardness of thecarbon particles. Upon holding at a constant load, the fullerenederivedcarbon particles undergo unrecoverable deformation, and theindentation creep CIT increases with increasing particle hardness. Anincrease in hardness of the reinforcing carbon particles substantiallyimproves the wear resistance of the CM and decreases their frictioncoefficient.
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| 2. |
- Zhang, Shuangshuang, et al.
(författare)
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Discovery of carbon-based strongest and hardest amorphous material
- 2022
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Ingår i: National Science Review. - : Oxford University Press. - 2095-5138 .- 2053-714X. ; 9:1
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Tidskriftsartikel (refereegranskat)abstract
- Carbon is one of the most fascinating elements due to its structurally diverse allotropic forms stemming from its bonding varieties (sp, sp2, and sp3). Exploring new forms of carbon has always been the eternal theme of scientific research. Herein, we report the amorphous (AM) carbon materials with high fraction of sp3 bonding recovered from compression of fullerene C60 under high pressure and high temperature previously unexplored. Analysis of photoluminescence and absorption spectra demonstrates that they are semiconducting with a bandgap range of 1.5–2.2 eV, comparable to that of widely used amorphous silicon. Comprehensive mechanical tests demonstrate that the synthesized AM-III carbon is the hardest and strongest amorphous material known so far, which can scratch diamond crystal and approach its strength. The produced AM carbon materials combine outstanding mechanical and electronic properties, and may potentially be used in photovoltaic applications that require ultrahigh strength and wear resistance.
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| 3. |
- Zhang, Shuangshuang, et al.
(författare)
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Narrow-gap, semiconducting, superhard amorphous carbon with high toughness, derived from C60 fullerene
- 2021
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Ingår i: Cell Reports Physical Science. - : Elsevier. - 2666-3864. ; 2:9
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Tidskriftsartikel (refereegranskat)abstract
- New carbon forms that exhibit extraordinary physicochemical properties can be generated from nanostructured precursors under extreme pressure. Nevertheless, synthesis of such fascinating materials is often not well understood. That is the case of the C60 precursor, with irreproducible results that impede further progress in the materials design. Here, the semiconducting amorphous carbon, having band gaps of 0.1–0.3 eV and the advantages of isotropic superhardness and superior toughness over single-crystal diamond and inorganic glasses, is produced from fullerene at high pressure and moderate temperatures. A systematic investigation of the structure and bonding evolution is carried out with complementary characterization methods, which helps to build a model of the transformation that can be used in further high-pressure/high-temperature (high p,T) synthesis of novel nano-carbon systems for advanced applications. The amorphous carbon materials produced have the potential of accomplishing the demanding optoelectronic applications that diamond and graphene cannot achieve.
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