铜/金纳米涂层在温度梯度下的分子动力学模拟

Properties of Cu/Au Thin Films Under Temperature Gradient:a Molecular Dynamics Study

本文采用分子动力学模拟方法溅射制备和理想化建模得到调制周期为1.8 nm铜/3.6 nm金的纳米涂层样本,并研究涂层结构在温度梯度作用下的相关特性。结果表明不同纳米涂层在过渡界面处均存在共格生长界面层结构,其中溅射制备得到的涂层中存在一定的空位缺陷。这些缺陷将阻碍纳米涂层中的能量传递。同时共格生长界面层中的晶格失配和空位缺陷使得过渡界面层中粒子的活动能力增大,可能造成涂层在热应力作用下的失效。涂层中粒子运动功率图谱表明声子传递无明显规律。

The thin films with modulation period of 1.8 nm Cu/3.6 nm Au are obtained via deposit method and ideal created based on lattice constant to examine their characteristics under temperature gradient based on molecular dynamics simulations.The coherent lattice interface is found both at deposit and ideal thin films after annealing.Also,the vacancies is found clearly in the deposit thin films.The defect thin films would weak the energy transportation in the coatings.The vacancies and lattice mismatch could enlarge the mobility of atoms and result in the failure of coating under the thermal stress.The power spectrum of atoms＇ movement showed no apparent rule for phonon transportation in thin films.