SiC纳米线初期微观生长模式的理论计算与模拟研究

Theoretical Calculation and Simulation Research of Microcosmic Growth Pattern of SiC Nanowire in the Initial Stage

运用从头算分子动力学模拟的方法,模拟研究了气-液-固(VLS)生长机制下碳化硅纳米线(SiC NWs)在镍催化剂表面最初生长阶段的微观生长机理。结果表明:活性碳原子在镍催化剂表面上各位置的吸附能均大于活性硅原子,所以碳原子优先吸附在镍催化剂表面;随后,由于活性硅原子在已吸附在镍催化剂表面的碳原子上的吸附能要大于活性碳原子在其上的吸附能,使得活性硅原子优先吸附在碳原子上,形成活性碳原子与活性硅原子交替吸附生长的模式。

In this work,we employ the ab initio Molecular Dynamics Simulation method to simulate and study the nitial microcosmic growth pattern of SiC nanowire on the surface of nickel（Ni）catalyst based on the vapor-liquid-solid（VLS）growth mechanism.The results shows that the adsorption energy of active carbon（C）atom is greater than active silicon（Si）atom on each location of the surface of Ni catalyst.As a result,the carbon atoms adsorb preferentially on the surface of Ni catalyst and form an atomic layer.Along with the growth process continuously,the adsorption energy of active Si atom is larger than the active C atom,therefore the active Si atom adsorb preferentially on the C atomic layer and form the pattern of alternate growth for the active C atom and the active Si atom.