Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1789984 | Journal of Crystal Growth | 2015 | 7 Pages |
Abstract
Laser shock processing induced structural transformation in graphite cluster of about 3Â nm diameter is simulated through molecular dynamics simulations. The Brenner potential is utilized to characterize short-range order while Lennard-Jones potential for long-range order. The effect of high-energy laser shock on graphite was simulated with corresponding temperature and pressure load applied to the graphite cluster. The graphite cluster was found to transform into nano-diamond, crystal structures and amorphous carbon after heating-pressing and annealing-decompression by analyzing pair distribution function g(r) and atomic snapshots process. An interesting mechanism 'direct transfer-adsorption' for promoting peripheral carbon atoms of the graphite cluster into the inner layer and transforming bonds from sp2-type to sp3-type within the inner carbon atoms is investigated. The 'direct transfer-adsorption' mechanism, which prevails under the conditions of a temperature higher than 4300Â K and a pressure higher than 15Â GPa, is at fast cooling rates and high densities. And the 'direct transfer-adsorption' mechanism plays a key role in the conversion from graphite to diamond.
Keywords
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Condensed Matter Physics
Authors
X.D. Ren, S.X. Tang, L.M. Zheng, S.Q. Yuan, N.F. Ren, H.M. Yang, Y. Wang, W.F. Zhou, S.D. Xu,