Bond-order potential for transition metal carbide cluster for the growth simulation of a single-walled carbon nanotube
Bond-order potential for transition metal carbide cluster for the growth simulation of a single-walled carbon nanotube
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DOI：
10.1016/j.commatsci.2006.10.007
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发表时间：
2007-06
影响因子：
3.3
通讯作者：
Y. Shibuta;S. Maruyama
中科院分区：
文献类型：
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作者：
Y. Shibuta;S. Maruyama
以键序势函数的形式发展了过渡金属碳化物团簇的经典多体势能。通过对密度泛函理论(DFT)计算的结合能进行拟合，构造了碳原子与几个过渡金属原子(Fe、Co和Ni)之间的参数集。利用势函数，用经典分子动力学(MD)模拟方法研究了碳原子在金属小团簇中的聚集过程。Co团簇中的六角环数目增加的速度大约是Fe团簇中的两倍。这意味着石墨化晶格与Co原子的相互作用比与Fe原子的相互作用更强。在模拟中，钴原子团簇具有金属原子规则地分配和嵌入到六方碳网络中的晶体结构。相反，在Fe团簇的情况下，碳原子覆盖了整个表面。此外，使用几种过渡金属的假设fcc(111)面，研究了碳原子从2D密排小面感受到的势能面。势能极小值分布在六方网络上，表明二维密堆积小面可以作为形成石墨烯的模板。
A classical many-body potential for transition metal carbide cluster is developed in the form of the bond-order type potential function. The parameter sets between carbon atoms and several transition metal atoms (Fe, Co and Ni) are constructed by fitting binding energies from Density Functional Theory (DFT) calculations. Using the potential function, clustering process of carbon atoms to a small metal cluster is studied by classical molecular dynamics (MD) simulation. The number of hexagonal rings in the Co cluster increases about twice as fast as in the Fe cluster. This implies that the graphitic lattice interacts more strongly with Co atoms than with Fe atoms. A Co cluster has a crystal structure where metal atoms are regularly allocated and embedded in the hexagonal carbon network in the simulation. In contrast, carbon atoms cover the entire surface in case of the Fe cluster. Additionally, the potential energy surface that a carbon atom feels from a 2D closed-packed facet is examined using a hypothetical FCC(111) facet of several transition metals. The potential energy minima are distributed on the hexagonal network showing the 2D closed-packed facet can be a template where a graphene is formed.