Bond Order Potential For Carbon Research Articles

Cover Image, Volume 36, Issue 23

Journal of Computational ChemistryVolume 36, Issue 23 p. i-ii Cover ImageFree Access Cover Image, Volume 36, Issue 23 First published: 21 July 2015 https://doi.org/10.1002/jcc.24024AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Graphical Abstract On page 1719 (DOI: 10.1002/jcc.23949), X. W. Zhou, D. K. Ward, and M. E. Foster present a new parameterization of Pettifor's bond order potential for carbon, enabling direct molecular dynamics simulations of graphene growth on copper. In the image, the big bronze balls are copper atoms, red small balls are carbon atoms in an initial graphene island, and small blue balls are deposited carbon atoms. Traces of some selected depositing carbon atoms are shown by small gray balls at time-resolved locations. Without any assumptions regarding the graphene structures, other than the random addition of carbon adatoms, MD simulations have enabled high fidelity studies of defect formation during graphene growth. Volume36, Issue23September 5, 2015Pages i-ii RelatedInformation

An analytical bond-order potential for carbon.

Carbon is the most widely studied material today because it exhibits special properties not seen in any other materials when in nano dimensions such as nanotube and graphene. Reduction of material defects created during synthesis has become critical to realize the full potential of carbon structures. Molecular dynamics (MD) simulations, in principle, allow defect formation mechanisms to be studied with high fidelity, and can, therefore, help guide experiments for defect reduction. Such MD simulations must satisfy a set of stringent requirements. First, they must employ an interatomic potential formalism that is transferable to a variety of carbon structures. Second, the potential needs to be appropriately parameterized to capture the property trends of important carbon structures, in particular, diamond, graphite, graphene, and nanotubes. Most importantly, the potential must predict the crystalline growth of the correct phases during direct MD simulations of synthesis to achieve a predictive simulation of defect formation. Because an unlimited number of structures not included in the potential parameterization are encountered, the literature carbon potentials are often not sufficient for growth simulations. We have developed an analytical bond order potential for carbon, and have made it available through the public MD simulation package LAMMPS. We demonstrate that our potential reasonably captures the property trends of important carbon phases. Stringent MD simulations convincingly show that our potential accounts not only for the crystalline growth of graphene, graphite, and carbon nanotubes but also for the transformation of graphite to diamond at high pressure.

Structural studies of disordered carbons by high-energy X-ray diffraction

X-ray diffraction measurements were carried out on three samples of disordered, commercially produced carbons, AX21, CXV and BP71, on the ID15B beam-line at the European Synchrotron Radiation Facility (ESRF), Grenoble. Intensity data were converted to pair correlation functions via the Fourier transform. The results obtained show that the structure of the studied samples consists of one–four graphite-like layers, stacked without spatial correlations. The size of the ordered regions is in the range of 9–16 Å. The atomic arrangement within an individual layer can be described in terms of the paracrystalline ordering, in which lattice distortions propagate proportionally to the square root of interatomic distances. The paracrystalline structure was simulated by introducing the Stone–Wales defects (pair of two pentagons and two heptagons), randomly distributed in the network. The resulting structures were relaxed using the reactive empirical bond order potential for carbon–carbon interaction and the Lennard-Jones potential with parameters for interlayer interactions. Such defects lead to curvature of individual layers.

Erratum: Improved long-range reactive bond-order potential for carbon. I. Construction [Phys. Rev. B72, 214102 (2005)

Erratum: Improved long-range reactive bond-order potential for carbon. I. Construction [Phys. Rev. B<b>72</b>, 214102 (2005)

Intrinsic long-range bond-order potential for carbon: Performance in Monte Carlo simulations of graphitization

We propose a bond order potential for carbon with built-in long-range interactions. The potential is defined as the sum of an angular and coordination dependent short-range part accounting for the strong covalent interactions and a radial long-range part describing the weak interactions responsible, e.g., for the interplanar binding in graphite. The short-range part is a Brenner type of potential, with several modifications introduced to get an improved description of elastic properties and conjugation. Contrary to previous long-range extensions of existing bond order potentials, we prevent the loss of accuracy by compensating for the additional long-range interactions by an appropriate parametrization of the short-range part. We also provide a short-range bond order potential. In Monte Carlo simulations our potential gives a good description of the diamond to graphite transformation. For thin (111) slabs graphitization proceeds perpendicular to the surface as found in ab initio simulations, whereas for thick layers we find that graphitization occurs layer by layer.