Non-Traditional Carbon Semiconductors Prepared from Fullerite C60 and Carbyne under High Pressure

Lyapin, A. G.; Бражкин, В. В.; Lyapin, S. G.; Попова, С. В.; Varfolomeeva, T. D.; Voloshin, R. A.; Pronin, A. A.; Sluchanko, N. E.; Gavrilyuk, Alexander; Trojan, Ivan

doi:10.1002/(sici)1521-3951(199901)211:1<401::aid-pssb401>3.0.co;2-n

Cited by 39 publications

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“…The fraction of the sp 3 hybridized C atoms in the fi nal product significantly increases under pressures of 8-10 GPa. 14 Interest in carbon materials is due to their unique properties, e.g., superhardness, 4,8,15 superconductivity, 16,17 high plasticity, 4,15 and controlled anisotropy of elastic properties. 12 There is a demand for studies of the thermo dynamic properties of carbon materials and optimization of technology of their production.…”

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Thermodynamic properties of graphite-like nanostructures prepared by thermobaric treatment of fullerite C60

et al. 2008

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Temperature dependences of the heat capacities of disordered graphite like nanostructures prepared by the thermobaric treatment of fullerite C 60 (p = 2 and 8 GPa, T = 1373 K) were measured in the temperature ranges from 7 to 360 K in an adiabatic vacuum calorimeter and from 330 to 650 K in a differential scanning calorimeter. At Т < 50 K, the dependences obtained were analyzed using the Debye theory of the heat capacity of solids and its multifractal version. The fractal dimensions D were determined and some conclusions on the heterodynamic charac ter of the structures studied were made. The thermodynamic functions С р°( Т), Н°(Т) -Н°(0), S°(T) -S°(0), and G°(T) -H°(0) were calculated in the temperature range from Т → 0 to 610 (650) K. The thermodynamic properties of the graphite like nanostructures studied and some carbon allotropes were compared. The standard entropies of formation Δ f S° of the graphite nanostructures studied and diamond were calculated along with the standard entropies of the reactions of their synthesis from the face centered cubic phase of fullerite C 60 and their inter conversions at Т = 298.15 K.There is considerable literature on the studies of fullerenes, their derivatives, and materials based on them. 1-8 The thermobaric treatment of fullerite C 60 followed by abrupt pressure drop from several GPa to р = 0.1 MPa and lowering the temperature to 298.15 K pro duces new carbon materials. 4-12 Under these conditions, the systems are thermodynamically metastable but kineti cally stable. In some cases, the thermobaric treatment of the face centered cubic (fcc) phase of fullerite C 60 causes breakdown of the molecular cage and formation of di sordered nanostructures 4,8,11-13 containing the sp 2 and sp 3 hybridized carbon atoms. These structures are similar in physicochemical properties to graphite and diamond. The fraction of the sp 3 hybridized C atoms in the fi nal product significantly increases under pressures of 8-10 GPa. 14 Interest in carbon materials is due to their unique properties, e.g., superhardness, 4,8,15 superconductivity, 16,17 high plasticity, 4,15 and controlled anisotropy of elastic properties. 12 There is a demand for studies of the thermo dynamic properties of carbon materials and optimization of technology of their production.The purpose of this work is to carry out a calorimetric study of the temperature dependences of the heat capacity of the graphite like nanostructures (GNS) produced by the thermobaric treatment of fullerite C 60 in the tempera ture interval from 7 to 610-650 K; to analyze these de pendences at T < 50 K in the framework of the Debye theory of the heat capacity of solids and its multifractal version; to calculate the standard thermodynamic func tions in the temperature range from Т → 0 to 610-650 K; to compare the standard thermodynamic properties of the GNS and some carbon allotropes; and to establish how their physicochemical properties depend on the structure. ExperimentalDoubly sublimed, finely crystalline powdered fullerite C 60 (grain size ~10...

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Thermodynamic properties of graphite-like nanostructures prepared by thermobaric treatment of fullerite C60

et al. 2008

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“…Carbyne is known to readily oxidize in air [16], which seems to be responsible for the relatively high oxygen content of our materials. The Raman spectrum of the as-prepared carbyne [17] showed a line near 2200 cm -1 , attributable to C=C vibrations, which confirmed the presence of sp carbon.…”

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confidence: 78%

“…In earlier studies [17,18,20], amorphous cumulenic carbyne was found to transform into a highly disordered graphite-like phase at high pressures and temperatures (500-900 ° C). Note that, if the parent carbyne is a high-resistivity semiconductor [17], processing at 600-800 ° C sharply reduces its resistivity [17,18].…”

Section: Introductionmentioning

confidence: 89%

“…At high pressures and temperatures, metastable carbon forms such as carbyne and C 60 fullerite transform into graphite or diamond, more stable phases, through a number of intermediate phases [17,18]. In fact, the average coordination number of carbon in the resulting phases can be varied almost continuously from 2 to 4 (from carbyne to diamond) [17]. High pressures and temperatures provide an effective means of producing new carbon materials which often have unique mechanical and physical properties [18,19].…”

Section: Introductionmentioning

confidence: 99%

“…Note that, if the parent carbyne is a high-resistivity semiconductor [17], processing at 600-800 ° C sharply reduces its resistivity [17,18]. As shown by Demishev et al [21][22][23][24] in studies of the electrical and galvanomagnetic properties of carbynes modified by exposure to high temperatures and pressures, the low-temperature conduction in such materials is due to hopping transport.…”

Section: Introductionmentioning

confidence: 99%

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High-Pressure Structural Transformations of Carbyne

et al. 2005

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The structure of cumulenic carbyne samples is studied by x-ray diffraction after exposure to high temperatures and pressures (200-900 ° C, 7.7 GPa). The results indicate that, with increasing temperature, carbyne transforms from a highly disordered to x-ray amorphous state, with narrower diffuse bands. At high temperatures, a disordered graphite-like structure is formed, with a density substantially lower than that of graphite. The behavior of impurities during the structural transformation of carbyne is discussed.

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Two‐Dimensional Fullerene Assembly from an Exfoliated van der Waals Template

et al. 2018

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Two-dimensional (2D) materials are commonly prepared by exfoliating bulk layered van der Waals crystals. The creation of synthetic 2D materials from bottom-up methods is an important challenge as their structural flexibility will enable chemists to tune the materials properties.A2D material was assembled using C 60 as ap olymerizable monomer.The C 60 building blocks are first assembled into alayered solid using am olecular cluster as structure director.T he resulting hierarchical crystal is used as atemplate to polymerizei ts C 60 monolayers,w hichc an be exfoliated down to 2D crystalline nanosheets.D erived from the parent template,t he 2D structure is composed of al ayer of inorganic cluster, sandwiched between two monolayers of polymerizedC 60 .The nanosheets can be transferred onto solid substrates and depolymerized by heating.Electronic absorption spectroscopy reveals an optical gap of 0.25 eV,narrower than that of the bulk parent crystalline solid.The discovery of graphene [1] has catalyzed acomprehensive search for two-dimensional (2D) materials,and has led to the development of 2D transition metal dichalcogenides,h exagonal boron nitride,a nd phosphorene. [2][3][4] These materials serve not only as excellent model systems for exploring 2D physics,b ut also as potential candidates for av ariety of electronic and optoelectronic devices.T raditional atomic 2D materials are commonly isolated from layered van der Waals solids exhibiting strong in-plane bonding and comparatively weak interactions between the layers.A ssembling molecular building blocks into synthetic 2D materials offers exciting opportunities for tuning the material properties through chemical design and for discovering new behaviors. [5][6][7] The assembly of such material, however, is am ajor synthetic challenge,w ith only af ew reported examples,w hich include 2D covalent organic frameworks [8][9][10][11] and metal-organic frameworks. [12,13] Herein, we describe an ew 2D material assembled from C 60 building blocks that are covalently linked. Then ano-material is formed by polymerizing al ayered van der Waals crystal assembled from C 60 and the molecular cluster Co 6 Se 8 -(PEt 2 phen) 6 (phen = 9-ethynylphenanthrene), and thereafter dissolving the supporting template (Figure 1a). Theresulting 2D structure is composed of al ayer of inorganic cluster, sandwiched between two monolayers of polymerized C 60 . Conceptually,t his structure can be visualized as as tructural analogue of 2D transition metal chalcogenides or halides in which the atomic building blocks are pseudo spherical molecular clusters rather than simply atoms. C 60 is an attractive building block for creating synthetic 2D structures owing to its remarkable physical and chemical properties.W hile crystalline C 60 has ab and gap of 2.3 eV, [14] theoretical studies on both polymeric and van der Waals C 60 monolayers predict band gaps ranging from 0.58 to 1.01 eV, [15][16][17][18] which is lower than that of any experimentally isolated monolayer semiconducting materials. [19] Additi...

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Non-Traditional Carbon Semiconductors Prepared from Fullerite C60 and Carbyne under High Pressure

Cited by 39 publications

References 24 publications

Thermodynamic properties of graphite-like nanostructures prepared by thermobaric treatment of fullerite C60

Thermodynamic properties of graphite-like nanostructures prepared by thermobaric treatment of fullerite C60

High-Pressure Structural Transformations of Carbyne

Two‐Dimensional Fullerene Assembly from an Exfoliated van der Waals Template

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