Centre Interdisciplinaire de Nanoscience de Marseille, Aix-Marseille University and CNRS, Campus de Luminy, Case 913, F-13288 Marseille, France.
Laboratoire d'Etude des Microstructures, ONERA-CNRS, BP 72, F-92322 Châtillon, France.
Phys Rev Lett. 2015 Nov 13;115(20):205502. doi: 10.1103/PhysRevLett.115.205502. Epub 2015 Nov 10.
The carbon rich phase diagrams of nickel-carbon nanoparticles, relevant to catalysis and catalytic chemical vapor deposition synthesis of carbon nanotubes, are calculated for system sizes up to about 3 nm (807 Ni atoms). A tight binding model for interatomic interactions drives the grand canonical Monte Carlo simulations used to locate solid, core shell and liquid stability domains, as a function of size, temperature, and carbon chemical potential or concentration. Melting is favored by carbon incorporation from the nanoparticle surface, resulting in a strong relative lowering of the eutectic temperature and a phase diagram topology different from the bulk one. This should lead to a better understanding of the nanotube growth mechanisms.
镍-碳纳米粒子富碳相图与催化和催化化学气相沉积合成碳纳米管有关，针对系统尺寸高达约 3nm（807 个镍原子）进行了计算。用于定位固、核壳和液稳定域的巨正则蒙特卡罗模拟由原子间相互作用的紧束缚模型驱动，其大小、温度以及碳化学势或浓度的函数。通过从纳米粒子表面掺入碳，有利于熔化，从而导致共晶温度大幅降低，并且相图拓扑结构与体相不同。这应该有助于更好地理解纳米管生长机制。
