Xie Lu, An Haojie, Peng Qing, Qin Qin, Zhang Yong
School of Mechanical Engineering, University of Science and Technology Beijing, Beijing 100083, China.
Nuclear Engineering and Radiological Sciences University of Michigan, Ann Arbor, MI 48108, USA.
Materials (Basel). 2018 Dec 14;11(12):2548. doi: 10.3390/ma11122548.
We have investigated the glass formation ability of Cu-Zr alloy by molecular dynamics simulation of the deposition process. The atomistic structures of ZrCu metallic glass films have been systematically examined under the growth conditions of hypereutectic-eutectic, near-eutectic, and hypoeutectic regions by the radial distribution function and simulated X-ray diffraction. The structure analysis using Voronoi polyhedron index method demonstrates the variations of short-range order and five-fold local symmetry in ZrCu metallic glass films with respect to the growth conditions. We manifest that the five-fold local symmetry is sensitive to the kinetic energy of the depositing atoms. There is positive correlation between the degree of five-fold local symmetry and glass forming ability. Our results suggest that sputtering conditions greatly affect the local atomic structures and consequential properties. The glass forming ability could be scaled by the degree of five-fold local symmetry. Our study might be useful in optimizing sputtering conditions in real experiments, as well as promising implications in material design of advanced glassy materials.
我们通过对沉积过程的分子动力学模拟研究了Cu-Zr合金的玻璃形成能力。利用径向分布函数和模拟X射线衍射，系统地研究了ZrCu金属玻璃薄膜在过共晶-共晶、近共晶和亚共晶区域生长条件下的原子结构。使用Voronoi多面体指数方法进行的结构分析表明，ZrCu金属玻璃薄膜的短程有序和五次局部对称性随生长条件而变化。我们发现五次局部对称性对沉积原子的动能很敏感。五次局部对称性程度与玻璃形成能力之间存在正相关。我们的结果表明，溅射条件极大地影响局部原子结构和相应的性能。玻璃形成能力可以通过五次局部对称性程度来衡量。我们的研究可能有助于在实际实验中优化溅射条件，以及对先进玻璃材料的材料设计具有潜在的意义。
