TITLE

Molecular dynamics study of tracer diffusion of argon adsorbed on amorphous surfaces

AUTHOR(S)
Riccardo, J. L.; Steele, W. A.
PUB. DATE
December 1996
SOURCE
Journal of Chemical Physics;12/1/1996, Vol. 105 Issue 21, p9674
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
An isokinetic molecular dynamics simulation of argon adsorbed on several model amorphous surfaces of titanium dioxide is carried out. The solid is represented by the Bernal Model in which the surface is taken to be the exposed face of a dense random packing of oxide ions. This surface is roughened by deleting varying numbers of oxides at random from the outer layer of the solid. Surface diffusion in the limit of very low coverage (tracer diffusion) is evaluated by following the dynamics of noninteracting single adatoms. The diffusion coefficient in the zero-density limit is calculated from velocity autocorrelation functions for adatoms at several temperatures ranging from 85 to 300 K. The temperature dependence of the diffusion constants obtained in this way shows nearly Arrhenius behavior in this temperature range. It is shown that surface roughening at the atomic scale give rise to a higher apparent activation energy for diffusion. A statistical characterization of the adsorptive field through distributions of local maxima and minima in the adsorption energy surface along the diffusion paths was performed in order to relate the surface diffusion of monatomic species on amorphous surfaces to the recently proposed Dual Site-Bond Description of Heterogeneous Surfaces (DSBD). Independent evidence supporting the theoretical hypothesis of the DSBD is also obtained. © 1996 American Institute of Physics.
ACCESSION #
7610488

 

Related Articles

  • LJ: LETTERS.  // LJ: Library Journal;3/15/1975, Vol. 100 Issue 6, p531 

    Presents letters from librarians commenting on the previous articles published in the 'Library Journal.' Views of John McCallum, reference collection librarian of the Wilfrid Laurier University, on the availability problem and poor performance of academic libraries; Appreciation of Carla N....

  • Diffusion coefficients of small gas molecules in amorphous cis-1,4-polybutadiene estimated by molecular dynamics simulations. Meunier, M. // Journal of Chemical Physics;10/1/2005, Vol. 123 Issue 13, p134906 

    Molecular dynamics (MD) simulations were employed to estimate the diffusion coefficients of small gas molecules (Ar, O2, N2, CO2, and CH4) in amorphous cis-1,4-polybutadiene in the temperature range of 250–400 K. The VT diagram and solubility parameter of the amorphous polymer have been...

  • Sodium diffusion through amorphous silica surfaces: A molecular dynamics study. Rarivomanantsoa, Michaël; Jund, Philippe; Jullien, Rémi // Journal of Chemical Physics;3/8/2004, Vol. 120 Issue 10, p4915 

    We have studied the diffusion inside the silica network of sodium atoms initially located outside the surfaces of an amorphous silica film. We have focused our attention on structural and dynamical quantities, and we have found that the local environment of the sodium atoms is close to the local...

  • Structure and diffusion in amorphous aluminum silicate: A molecular dynamics computer simulation. Winkler, Anke; Horbach, Jürgen; Kob, Walter; Binder, Kurt // Journal of Chemical Physics;1/1/2004, Vol. 120 Issue 1, p384 

    The amorphous aluminum silicate (Al[sub 2]O[sub 3])2(SiO[sub 2]) [AS2] is investigated by means of large scale molecular dynamics computer simulations. We consider fully equilibrated melts in the temperature range 6100 K>=T>=2300 K as well as glass configurations that were obtained from cooling...

  • Molecular dynamics simulation of local chain motion in bulk amorphous polymers. I. Dynamics above the glass transition. Takeuchi, Hisao; Roe, Ryong-Joon // Journal of Chemical Physics;6/1/1991, Vol. 94 Issue 11, p7446 

    The local chain dynamics of bulk amorphous polymers above the glass transition temperature is studied by means of molecular dynamics simulations in the time scale up to 10-9 s. A model of polyethylene having a realistic density is used where a fully vibrational treatment is applied to the chains...

  • Molecular dynamics study on Ar ion bombardment effects in amorphous SiO2 deposition processes. Taguchi, Masafumi; Hamaguchi, Satoshi // Journal of Applied Physics;12/15/2006, Vol. 100 Issue 12, p123305 

    Argon ion bombardment effects on growing amorphous SiO2 films during reactive sputtering deposition processes were examined based on molecular dynamics (MD) and Monte Carlo (MC) simulation techniques. The system we have considered here is a film that is subject to energetic Ar bombardment while...

  • Gas diffusion in glasses via a probabilistic molecular dynamics. Willmore, Frank T.; Xiao-Yan Wang; Sanchez, Isaac C. // Journal of Chemical Physics;6/21/2007, Vol. 126 Issue 23, p234502 

    A probabilistic protocol which makes possible the calculation of the diffusivity of light gases in amorphous materials from limited Monte Carlo and molecular dynamics data is presented. Diffusion coefficients are calculated for helium and methane in polystyrene, and for helium, neon, and methane...

  • Molecular dynamics simulation of local chain motion in bulk amorphous polymers. II. Dynamics at glass transition. Takeuchi, Hisao; Roe, Ryong-Joon // Journal of Chemical Physics;6/1/1991, Vol. 94 Issue 11, p7458 

    The local chain dynamics of bulk amorphous polymers has been studied by means of molecular dynamics simulation in the vicinity of the glass transition temperature Tg. Two models of polymers are used, one mimicking a polyethylene chain and the other a hypothetical freely-rotating chain, both of...

  • Local vibrational densities of states in glasses: Numerical study of a model of amorphous silicon. Ishibashi, Kiyoshi; Tsumuraya, Kazuo; Nakata, Shinji // Journal of Chemical Physics;7/15/1994, Vol. 101 Issue 2, p1412 

    We analyze for the first time the relation between the shape of the local vibrational densities of states (LDOSs) and the local environments of atoms in glasses. We calculated the LDOSs in model silicon glasses by use of a recursion method. The glasses are produced by a constant pressure...

Share

Read the Article

Courtesy of THE LIBRARY OF VIRGINIA

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics