分子动力学模拟尺寸对纳米Cu颗粒等温晶化过程的影响  

Molecular dynamics simulation of isothermal crystallization dynamics in Cu nanocluster

作　　者：陈青[1] 孙民华[1] 

机构地区：[1]光电带隙材料省部共建教育部重点实验室,哈尔滨师范大学物理与电子工程学院,哈尔滨150025

出　　处：《物理学报》2013年第3期217-222,共6页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:10947009)资助~~

摘　　要：采用分子动力学方法和镶嵌原子势,模拟了4000个Cu原子和13500个Cu原子(简称Cu4000和Cu13500)组成的纳米颗粒以及块体Cu的等温晶化过程.通过对这些颗粒在晶化过程中结构和动力学行为的分析研究,发现低温时,不同尺寸的纳米Cu颗粒均出现多步晶化,且晶化时间的分布曲线远比高温时范围大;除了温度,颗粒尺寸对晶化行为也有重要的影响,尺寸越大,晶化时间越长,最终的晶化程度越高;但是晶化时间随尺寸增大而增加的趋势不会一直持续,发现存在一个临界尺寸rc,小于rc时,晶化时间随颗粒尺寸增大而增加,大于rc时,晶化时间随尺寸增大而减小.We investigate the isothermal crystallizations of nanoparticles composed, respectively, of 4000 Cu atoms （Cu4000） and 13500 Cu atoms （Cu13500）, and bulk Cu according to on embedded atom model, using molecular dynamics simulations. We note that different sizes of Cu nanoparticles display multistep crystallization at low temperature, and their crystallization time distribution is wider than at high temperature, shown by analyzing the structural and dynamic properties of isothermal crystallization. Moreover, the size of particle plays an important role in the crystallization process. The larger the size, the longer the crystallization time is. However, we find that there is a critical size rc. The crystallization time increases with particle size increasing when the size is less than rc. On the contrary, when the size is more than rc, the crystallization time decreases with particle size increasing.

关 键 词：分子动力学模拟 纳米Cu 等温晶化 临界尺寸 

分 类 号：O561[理学—原子与分子物理]