中国物理B ›› 2015, Vol. 24 ›› Issue (9): 96203-096203.doi: 10.1088/1674-1056/24/9/096203

• CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES • 上一篇    下一篇

ReaxFF molecular dynamics study on oxidationbehavior of 3C-SiC: Polar face effects

孙瑜a, 刘轶军a b, 徐绯a   

  1. a Institute for Computational Mechanics and Its Applications, Northwestern Polytechnical University, Xi'an 710072, China;
    b Mechanical Engineering, University of Cincinnati, Cincinnati, Ohio 45221-0072, USA
  • 收稿日期:2015-03-09 修回日期:2015-04-07 出版日期:2015-09-05 发布日期:2015-09-05
  • 基金资助:

    Project supported by the 111 Project (Grant No. B07050) and the National Natural Science Foundation of China (Grant No. 11402206).

ReaxFF molecular dynamics study on oxidationbehavior of 3C-SiC: Polar face effects

Sun Yu (孙瑜)a, Liu Yi-Jun (刘轶军)a b, Xu Fei (徐绯)a   

  1. a Institute for Computational Mechanics and Its Applications, Northwestern Polytechnical University, Xi'an 710072, China;
    b Mechanical Engineering, University of Cincinnati, Cincinnati, Ohio 45221-0072, USA
  • Received:2015-03-09 Revised:2015-04-07 Online:2015-09-05 Published:2015-09-05
  • Contact: Sun Yu E-mail:npuyusun@gmail.com
  • Supported by:

    Project supported by the 111 Project (Grant No. B07050) and the National Natural Science Foundation of China (Grant No. 11402206).

摘要:

The oxidation of nanoscale 3C-SiC involving four polar faces (C(100), Si(100), C(111), and Si(111)) is studied by means of a reactive force field molecular dynamics (ReaxFF MD) simulation. It is shown that the consistency of 3C-SiC structure is broken over 2000 K and the low-density carbon chains are formed within SiC slab. By analyzing the oxygen concentration and fitting to rate theory, activation barriers for C(100), Si(100), C(111), and Si(111) are found to be 30.1, 35.6, 29.9, and 33.4 kJ·mol-1. These results reflect lower oxidative stability of C-terminated face, especially along [111] direction. Compared with hexagonal polytypes of SiC, cubic phase may be more energy-favorable to be oxidized under high temperature, indicating polytype effect on SiC oxidation behavior.

关键词: molecular dynamics, ReaxFF field, 3C-SiC, oxidation

Abstract:

The oxidation of nanoscale 3C-SiC involving four polar faces (C(100), Si(100), C(111), and Si(111)) is studied by means of a reactive force field molecular dynamics (ReaxFF MD) simulation. It is shown that the consistency of 3C-SiC structure is broken over 2000 K and the low-density carbon chains are formed within SiC slab. By analyzing the oxygen concentration and fitting to rate theory, activation barriers for C(100), Si(100), C(111), and Si(111) are found to be 30.1, 35.6, 29.9, and 33.4 kJ·mol-1. These results reflect lower oxidative stability of C-terminated face, especially along [111] direction. Compared with hexagonal polytypes of SiC, cubic phase may be more energy-favorable to be oxidized under high temperature, indicating polytype effect on SiC oxidation behavior.

Key words: molecular dynamics, ReaxFF field, 3C-SiC, oxidation

中图分类号:  (Mechanical properties of nanoscale systems)

  • 62.25.-g
81.16.Pr (Micro- and nano-oxidation) 61.46.-w (Structure of nanoscale materials)