物理化学学报Issue(11)：2015-2023,9.DOI:10.3866/PKU.WHXB201409101
不同孪晶界密度银纳米线拉伸形变行为的分子动力学模拟
Molecular Dynamics Simulation of the Deformation Behavior of Ag Nanowires with Different Twin Boundary Density under Tension Loading
摘要
Abstract
The deformation mechanisms and mechanical tensile behavior of Ag nanowires containing different densities of paral el twin boundaries were investigated using molecular dynamics simulations. The effect of twin boundaries on the Young′s modulus in nanowires was not obvious in the elastic deformation stage. After the elastic deformation stage, the initial dislocation from the edge of the free surfaces in nanowires resulted in plastic deformation. The existence of the twin boundary in nanowires wil cause the spread of the dislocation and act as sources of dislocations with the assistance of the newly formed defects with further tension load. The simulation showed that the mechanical strength of Ag nanowires was highly dependent on the twin boundary spacing and the size of the grain, resulting from the aspect ratio between the spacing distance and the length of the cross-section. In particular, twinned Ag nanowires with smal twin density (aspect ratio>1) had smal yielding stresses, even less than that of the single crystal Ag nanowires. Only with large twin density (aspect ratio<1) can the nanowires be strengthened by the structure of the twin boundaries. We also investigated the effects of tensile rate and temperature on the yielding strength of the Ag nanowires. With increasing temperature, the difference of yielding stress between twinned nanowires and single crystal nanowires first increased and then decreased to a stable level. With increasing tensile rate, this difference showed the opposite trend.关键词
银纳米线/孪晶界/单轴拉伸/分子动力学模拟/纳米器件/长径比Key words
Ag nanowire/Twin boundary/Uniaxial tension/Molecular dynamics simulation/Nanometer device/Aspect ratio分类
化学化工引用本文复制引用
孙倩,杨熊博,高亚军,赵健伟..不同孪晶界密度银纳米线拉伸形变行为的分子动力学模拟[J].物理化学学报,2014,(11):2015-2023,9.基金项目
The project was supported by the National Natural Science Foundation of China (21273113,21121091) and National Key Technology R&D Program of China (2012BAF03B05).国家自然科学基金(21273113,21121091)和国家科技支撑计划项目(2012BAF03B05)资助 （21273113,21121091）
