Structural and dynamical properties of liquid Al-Au alloys
Structural and dynamical properties of liquid Al-Au alloys
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DOI：
10.1103/physrevb.92.184201
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发表时间：
2015-11
影响因子：
3.7
通讯作者：
H. Peng;T. Voigtmann;G. Kolland;H. Kobatake;J. Brillo
中科院分区：
文献类型：
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作者：
H. Peng;T. Voigtmann;G. Kolland;H. Kobatake;J. Brillo
本文研究了Al-Au熔体的结构和动力学性质随温度和成分的变化。进行实验以获得准确的密度和粘度数据。该系统显示出强烈的负过剩体积，类似于其他铝基二元合金。我们基于嵌入原子方法（EAM）开发了熔体的分子动力学（MD）模型，并根据可用的实验液态数据进行衡量。固态Au和Al的前EAM电位的重新缩放提高了与熔体中的实验数据的定量一致性。在MD模拟中，Au与Al的混合物可以被解释为导致较不致密的Al系统的局部压缩，由较不软的Au-Au相互作用驱动。这种局部压缩提供了一种解释熔体强负过剩体积的微观机制。我们进一步讨论了MD模型中自扩散、互扩散和粘性的浓度依赖性。Al原子比Au更移动的，并且它们增加的移动性与熔体的较低粘度有关。
We investigate temperature- and composition dependent structural and dynamical p roperties of Al-Au melts. Experiments are performed to obtain accurate density and viscosity data. The system shows a strong negative excess volume, similar to other Al-based binary alloys. We develop a molecular-dynamics (MD) model of the melt based on the embedded-atom method (EAM), gauged against the available experimental liquid-state data. A rescaling of previous EAM potentials for solid-state Au and Al improves the quantitative agreement with experimental data in the melt. In the MD simulation, the admixture of Au to Al can be interpreted as causing a local compression of the less dense Al system, driven by less soft Au--Au interactions. This local compression provides a microscopic mechanism explaining the strong negative excess volume of the melt. We further discuss the conentration dependence of self- and interdiffusion and viscosity in the MD model. Al atoms are more mobile than Au, and their increased mobility is linked to a lower viscosity of the melt.