镁/镀镍碳纳米管界面特性电子理论研究

Electronic theory study of interface characteristic of magnesium/carbon nanotube with nickel

建立了复合材料中(镀镍)碳纳米管/镁界面原子集团模型,采用递归法计算了界面电子结构.计算表明:镀镍碳纳米管与镁形成的界面结构能、原子结合能较低,镍能够加大纳米管/基体界面结构的稳定性,促进界面结合强度的提高;在界面镍镀层中镁原子的相互作用能为正,说明镍镀层中的镁原子相互排斥,不能形成原子团簇,具有有序化倾向,形成起到强化界面作用的有序相;碳、镁原子在未镀镍碳纳米管与镁的界面格位能较高,降低界面稳定性,因而界面比较脆弱.碳纳米管镀镍后,镍使界面处镁、碳的格位能大幅降低,界面稳定性增强.

The atomic cluster models of Mg/CNT（carbon nanotube or nickel carbon nanotube） interface have been built in magnesium composite reinforced by （nickel） carbon nanotube. The interface electronic structures have been calculated by recursion method. The calculated results show that nickel enhances the stability of nanotube/matrix interface, improves the interface bond strength, since nickel makes the structure energy and atomic binding energy of nanotube/matrix interface lowered. The positive interaction energy of magnesium atoms in nickel film of interface causes the magnesium atoms in nickel film to repel each other and can not form magnesium atomic cluster, so they prefer to form ordering phase which consolidate the interface. The carbon and magnesium atoms have higher energy of position, which causes interface instability and flimsiness at carbon nanotube without nickel plating and magnesium interface. But when the carbon nanotubes have been plated by nickel, the energy of position of carbon and magnesium atoms are made lower and the interface gets more stable and tough.