A ReaXFF carbon potential for radiation damage studies

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS

卷:393

Article; Proceedings Paper

Smith, Roger¹  Jolley, Kenny¹  Latham, Chris²  Heggie, Malcolm³  van Duin, Adri⁴  van Duin, Diana⁴  Wu, Houzheng⁵ 

[1] Loughborough Univ Technol, Dept Math Sci, Loughborough LE11 3TU, Leics, England

[2] Univ Surrey, Dept Chem, Surrey GU2 5XH, England

[3] Loughborough Univ Technol, Dept Chem, Loughborough LE11 3TU, Leics, England

[4] RxFF Consulting, 2398 Charleston Dr, State Coll, PA 16801 USA

[5] Univ Loughborough, Dept Mat, Loughborough LE11 3TU, Leics, England

关键词: Graphite;    Semi-empirical potential;    Density-functional calculations;    Defects;    Cascades;   

DOI  :  10.1016/j.nimb.2016.11.007

来源: Elsevier

【 摘 要 】

Although molecular dynamics simulations of energetic impacts and collision cascades in graphite have been investigated for over 25 years, recent investigations have shown a difference between the types of defects predicted by the commonly used empirical potentials compared to ab initio calculations. As a result a new ReaXFF potential has been fitted which reproduces the formation energies of many of the defects predicted by the ab initio calculations and the energy pathways between different defect states, important for investigating long term defect evolution. The data sets in the fitting have been added to the existing data sets used for modelling hydrocarbons and fullerenes. The elastic properties of the potential are less well modelled than the point defect structures with the elastic constants c33 being too high and c44 too low compared to experiment. Preliminary results of low energy collision cascades show many point defect structures develop that are in agreement with those predicted from the ab initio results. (C) 2016 The Authors. Published by Elsevier B.V.

【 授权许可】

Free