Molecular dynamics simulation for the sintering process of Au nanoparticles
Molecular dynamics simulation for the sintering process of Au nanoparticles
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Au纳米颗粒烧结过程的分子动力学模拟
DOI：
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
Qu, Xuan-Hui
中科院分区：
文献类型：
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作者：
Cui, Ya-Nan;Chen, Xiao-Wei;He, Xin-Bo;Qu, Xuan-Hui
采用分子动力学模拟方法研究了金纳米粒子的烧结过程，分析了不同粒径金纳米粒子的晶体结构转变和颈部生长机制，发现两种纳米粒子的聚结过程经历了两个阶段，模拟结果表明，不同的颗粒尺寸会导致不同的颈缩生长机制，当颗粒尺寸较大时，当颗粒尺寸为4 nm时，主要的颈生长机制为晶界/位错滑移、表面扩散和粘性流动;当颗粒尺寸为6 nm时，主要的颈生长机制为晶界扩散、表面扩散和粘性流动;当颗粒尺寸为9 nm时，主要的颈生长机制为晶界扩散和表面扩散。颗粒的fcc结构逐渐转变为非晶态结构，同时由于晶界滑移或粘性流动，在小尺寸颗粒中形成hcp晶体结构。
The sintering process of gold nanoparticles was investigated using molecular dynamics simulation,and the detailed crystal structure transformation and neck growth mechanisms were identified and analyzed for different particle sizes.It is found that the coalescence of two nanoparticles experiences two stages,which are the initial rapid neck formation and stable neck growth.Simulation results show that different particle sizes lead to different neck growth mechanisms.When the particle size is 4 nm,the major neck growth mechanisms are grain-boundary / dislocation slid,surface diffusion,and viscous flow.For the particles with the size of about 6 nm,the major neck growth mechanisms are grain-boundary diffusion,surface diffusion,and viscous flow.But when the particle size is 9 nm,the major neck growth mechanisms are grain-boundary diffusion and surface diffusion.During the sintering process,the fcc structure of the particles transforms to amorphous structure gradually.Besides,the hcp crystal structure forms in the small sized particles because of grain-boundary slid or viscous flow.