论文标题
单壁碳纳米管生长
A Semi-Grand Canonical Kinetic Monte Carlo study of Single-Walled Carbon Nanotubes growth
论文作者
论文摘要
单壁碳纳米管存在于各种不同的几何形状，所谓的手势，这些碳纳米管定义了它们的电子特性。在催化化学蒸气沉积合成实验中已经报道了手性选择性，但潜在的机制仍然很少了解。在这一贡献中，我们为预测不同手势的碳纳米管的生长速率建立了一个简单的模型，这是表征碳纳米管催化剂界面和合成参数的能量的函数。该模型在半宏观规范集合中使用动力学蒙特卡洛模拟有效地取样，从而发现了外部实验条件的相互作用以及界面与催化剂的构型和能量。特别是，手性角度依赖性生长速率的分布遵循非单调趋势随界面能量的函数。我们分析了这种行为，并使用它来确定导致各种手性角度选择性高的条件。
Single-walled carbon nanotubes exist in a variety of different geometries, so-called chiralities, that define their electronic properties. Chiral selectivity has been reported in catalytic chemical vapor deposition synthesis experiments, but the underlying mechanisms remain poorly understood. In this contribution, we establish a simple model for the prediction of the growth rates of carbon nanotubes of different chiralities, as a function of energies characterizing the carbon nanotube-catalyst interface and of parameters of the synthesis. The model is sampled efficiently using kinetic Monte Carlo simulations in the semi-grand canonical ensemble, uncovering the interplay of the external experimental conditions and the configuration and energetics of the interface with the catalyst. In particular, the distribution of chiral angle dependent growth rates follows non-monotonic trends as a function of interface energies. We analyze this behavior and use it to identify conditions that lead to high selectivity for a variety of chiral angles.
