Thumbnail
Access Restriction
Open

Author Morris, J. R. ♦ Fu, C. L. ♦ Ho, K. M.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword MATERIALS SCIENCE ♦ DIAMONDS ♦ GRAIN BOUNDARIES ♦ COMPUTERIZED SIMULATION ♦ TWINNING ♦ DISLOCATIONS ♦ MATHEMATICAL MODELS ♦ ORIENTATION ♦ TIGHT BINDING APPROXIMATION
Abstract We have examined a number of symmetric tilt grain boundary structures in diamond, using a transferable tight-binding (TB) carbon potential. Utilizing {ital O}({ital N}) tight-binding molecular dynamics, we are able to simulate several thousands of atoms, allowing us to examine low-angle boundaries with large periodicities. The lowest energy structure is the {l_brace}111{r_brace} twin boundary, corresponding to the {Sigma}=3 70.53{degree} grain boundary. For angles less than 70.53{degree}, the boundaries are composed of a series of {ital b}={l_angle}01{bar 1}{r_angle} edge dislocations. The core structures of these dislocations are composed of five- and seven-atom rings. For these low-angle structures, the tight-binding energies have trends similar to those found using a Tersoff potential; both models give results that are consistent with linear elasticity theory. For the high-angle {l_brace}211{r_brace} and {l_brace}311{r_brace} boundaries, the tight-binding model predicts a reconstruction along the {l_angle}011{r_angle} direction, in order to eliminate dangling bonds. {copyright} {ital 1996 The American Physical Society.}
ISSN 01631829
Educational Use Research
Learning Resource Type Article
Publisher Date 1996-07-01
Publisher Department Oak Ridge National Laboratory
Publisher Place United States
Journal Physical Review, B: Condensed Matter
Volume Number 54
Issue Number 1
Organization Oak Ridge National Laboratory


Open content in new tab

   Open content in new tab