Molecular dynamics simulations of simple monatomic amorphous nanoparticles
Molecular dynamics simulations of simple monatomic amorphous nanoparticles
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DOI：
10.1103/physrevb.77.125434
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发表时间：
2008-03
影响因子：
3.7
通讯作者：
V. V. Hoang-V.;T. Odagaki
中科院分区：
文献类型：
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作者：
V. V. Hoang-V.;T. Odagaki
在非周期边界条件下，采用分子动力学方法研究了含1189 ~ 9093个不同原子数的单原子非晶态纳米颗粒的球形模型。我们利用Engel和Trebin提出的双阱相互作用对势，对熔体进行冷却得到了非晶纳米粒子。通过径向分布函数、平均原子距离、配位数和键角分布研究了纳米颗粒的结构特性。此外，我们还利用Honeycutt和Andersen提出的技术分析了纳米颗粒的局部有序，发现体系中存在二十面体有序。我们发现纳米颗粒的静态性能有很强的尺寸效应。观察并讨论了老化对纳米颗粒结构的影响。发现并讨论了纳米粒子的径向原子密度分布。另一方面，对纳米颗粒的表面和核心结构进行了详细的研究。此外，我们还发现了纳米粒子的玻璃化转变温度、势能和表面能等物理量的尺寸依赖性。讨论了原子的均方位移。
Monatomic amorphous nanoparticles were studied in a spherical model containing different numbers of atoms ranging from 1189 to 9093 by using molecular dynamics method under nonperiodic boundary conditions. We use the double-well interaction pair potential developed by Engel and Trebin, and amorphous nanoparticles were obtained by cooling from the melts. The structural properties of nanoparticles were studied via radial distribution function, mean atomic distances, coordination number, and bond-angle distributions. In addition, we also analyzed local order in nanoparticles by using the technique proposed by Honeycutt and Andersen, and we found the existence of icosahedral order in the system. We found strong size effects on the static properties of nanoparticles. Aging effects on the structure of nanoparticles were also observed and discussed. The radial atomic density profile of nanoparticles was found and discussed. On the other hand, the surface and core structures of nanoparticles were studied in detail. Moreover, we found the size dependence of several quantities such as the glass transition temperature, the potential energy, and surface energies of nanoparticles. The mean-squared displacement of atoms was discussed.