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Related papers: Understanding the nature of "superhard graphite"

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New carbon forms exhibiting extraordinary physico-chemical properties can be generated from nanostructured precursors under extreme pressure. Nevertheless, synthesis of such fascinating materials is often not well understood that results,…

Results based on {\em ab initio} density functional calculations indicate a general graphitization tendency in ultrathin slabs of cubic diamond, boron nitride, and many other cubic structures including rocksalt. Whereas such compounds often…

Materials Science · Physics 2015-06-22 Pavel B. Sorokin , Alexander G. Kvashnin , Zhen Zhu , David Tománek

Large area graphene sheets grown by chemical vapor deposition can potentially be employed as a transparent electrode in photovoltaics if their sheet resistance can be significantly lowered, without any loss in transparency. Here, we report…

Materials Science · Physics 2015-12-16 Ahmed A. Maarouf , Amal Kasry , Bhupesh Chandra , Glenn J. Martyna

Transition metal nitrides have been suggested to have both high hardness and good thermal stability with large potential application value, but so far stable superhard transition metal nitrides have not been synthesized. Here, with our…

Materials Science · Physics 2018-11-30 Kang Xia , Hao Gao , Cong Liu , Jian Sun , Hui-Tian Wang , Dingyu Xing

The supramolecular preorganization approach can be applied to effectively fabricate various morphologies of graphitic carbon nitride(g-CN)with improved photocatalytic activity, while a comprehensive understanding for the morphology…

Mesoscale and Nanoscale Physics · Physics 2020-04-10 Wu Wang , Zongzhao Sun , Jianghe Feng , Juan Cui , Limin Huang , Jiaqing He

A model for the formation of carbon nanotubes (CNTs) and layered graphene in an arc discharge method is developed on the basis of observed erosion of graphite anode under various experimental conditions and analyses of the morphology of the…

Materials Science · Physics 2019-07-23 Soumen Karmakar

Thermal decomposition of silicon carbide is a promising approach for the fabrication of graphene. However, the atomistic growth mechanism of graphene remains unclear. This paper describes the development of a new charge-transfer interatomic…

Materials Science · Physics 2018-03-13 So Takamoto , Takahiro Yamasaki , Jun Nara , Takahisa Ohno , Chioko Kaneta , Asuka Hatano , Satoshi Izumi

We describe a mechanism that explains the formation of hydrocarbons and hydrocarbyls from hydrogenated graphene/graphite; hard C-C bonds are weakened and broken by the synergistic effect of chemisorbed hydrogen and high temperature…

Mesoscale and Nanoscale Physics · Physics 2014-08-22 Jose I. Martinez , Jose A. Martin-Gago , Jose Cernicharo , Pedro L. de Andres

This work deals with the intrinsic and extrinsic properties of the graphene layers inside the graphite structure, in particular the influence of defects and interfaces. We discuss the evidence for ballistic transport found in mesoscopic…

Materials Science · Physics 2011-10-13 J. Barzola-Quiquia , A. Ballestar , S. Dusari , P. Esquinazi

We have studied the shock-induced phase transition from fullerite to a dense amorphous carbon phase by tight-binding molecular dynamics. For increasing hydrostatic pressures P, the C60-cages are found to polymerise at P<10 GPa, to break at…

Materials Science · Physics 2009-11-10 M. Moseler , H. Riedel , P. Gumbsch , J. Staring , B. Mehlig

We present an ab-initio study of boron nitride as well as carbon allotropes. Their relative thermodynamic stabilities and structural phase transitions from low- to high-density phases are investigated. Pressure-temperature phase diagrams…

Materials Science · Physics 2019-02-22 Thomas Gruber , Andreas Grüneis

Search for new high-temperature superconductors and insight into their superconducting mechanism are of fundamental importance in condensed matter physics. The discovery of near-room temperature superconductivity at more than a million…

Using density functional theory we investigate the occurrence of superconductivity in AC$_6$ with A=Mg,Ca,Sr,Ba. We predict that at zero pressure, Ba and Sr should be superconducting with critical temperatures (T$_c$) 0.2 K and 3.0 K,…

Superconductivity · Physics 2009-11-11 Matteo Calandra , Francesco Mauri

The power of polymorphism in carbon is vividly manifested by the numerous applications of carbon-based nano-materials. Ranging from environmental issues to biomedical applications, it has the potential to address many of today's dire…

Materials Science · Physics 2017-03-28 Obaidur Rahaman , Bohayra Mortazavi , Arezoo Dianat , Gianaurelio Cuniberti , Timon Rabczuk

Using first-principles calculations, we show that the formation of carbohydrate directly from carbon and water is energetically favored when graphene membrane is subjected to aqueous environment with difference in chemical potential across…

Mesoscale and Nanoscale Physics · Physics 2010-03-17 Wei L. Wang , Efthimios Kaxiras

Two sets of samples were synthesized at 3.5 GPa near the point of C60 cage collapse at different annealing times. A clear structural transformation from mixture of C60 polymeric phases to graphite-like hard carbon phase was confirmed by…

Materials Science · Physics 2009-11-11 K. -H. Han , A. Talyzin , A. Dzwilewski , T. L. Makarova , R. Hohne , P. Esquinazi , D. Spemann , L. S. Dubrovinsky

The physicochemical behavior of elements and compounds is heavily altered by high pressure. The occurrence of pressure-induced reactions and phase transitions can be revealed by crystal structure prediction approaches. In this work, we…

Materials Science · Physics 2016-03-09 Gabriele Saleh , Artem R. Oganov

Ubiquitous graphene is a stricly 2D material representing an ideal adsorbing platform due to its large specific surface area as well as its mechanical strength and resistance to both thermal and chemical stresses. However, graphene as a…

Materials Science · Physics 2016-10-06 Massimiliano Bartolomei , Giacomo Giorgi

A great efficacy of molecular quantum chemistry applied to basic graphene problems has been recently demonstrated by the authors when studying the formation of peculiar composites between carbon nanotubes and graphene as well as considering…

Mesoscale and Nanoscale Physics · Physics 2011-02-07 Elena F Sheka , Nadezhda A Popova

We study the superconducting phase transition, both in a graphene bilayer and in graphite. For that purpose we derive the mean-field effective potential for a stack of graphene layers presenting hopping between adjacent sheets. For…

Superconductivity · Physics 2020-10-05 Lizardo H. C. M. Nunes , E. C. Marino , A. L. Mota