Structure and dynamics of liquid Ni36Zr64byab initiomolecular dynamics
Structure and dynamics of liquid Ni36Zr64byab initiomolecular dynamics
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DOI：
10.1103/physrevb.83.184103
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发表时间：
2011-05
影响因子：
3.7
通讯作者：
Li Huang;C. Wang;K. Ho
中科院分区：
文献类型：
--
作者：
Li Huang;C. Wang;K. Ho
采用第一性原理分子动力学方法研究了液态NiZr合金在平衡态和过冷态下的局域结构与原子动力学之间的相互作用。的拓扑和化学短程订单（SRO）的特点是部分对相关函数与最近的中子散射实验显示出良好的一致性。三维结构分析表明，由于Ni和Zr原子间强的定向相互作用和较大的尺寸差异导致了二十面体的阻挫，Ni和Zr原子周围的局域环境比二十面体SRO更为复杂.原子动力学分析表明，Ni中心和Zr中心的Voronoi多面体具有相对较长的寿命，在减慢动力学过程中起着关键作用。随着液体冷却，这些团簇的分数显著增加，从而促进快速淬火合金中的玻璃形成。
First-principles molecular dynamics simulations are performed to investigate the interplay between the local structure and atomic dynamics of liquid NiZreutectic alloy in the equilibrium and undercooled states. The topological and chemical short-range orders (SROs) as characterized by the partial pair-correlation functions show good agreement with recent neutron-scattering experiments. Three-dimensional structural analysis shows that the local environment around both Ni and Zr atoms is more complex than the icosahedral SRO due to the frustration of icosahedra driven by the strong directional interaction and large size difference between Ni and Zr. The atomic dynamics analysis shows that the Ni-centeredand Zr-centeredVoronoi polyhedra with relatively longer lifetime play a key role in slowing down the dynamics. The fraction of these clusters increases significantly as the liquid is cooled down and thus facilitates glass formation in the rapidly quenched alloys.