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（Reax FF MD） simulation. It is shown that ...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（Reax FF 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 k J·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.展开更多
基金Project supported by the 111 Project(Grant No.B07050)the National Natural Science Foundation of China(Grant No.11402206)
文摘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（Reax FF 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 k J·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.
