The self-diffusion coefficients of liquid binary M-Si (M=Al, Fe, Mg and Au) alloy systems by first principles molecular dynamics simulation
The self-diffusion coefficients of liquid binary M-Si (M=Al, Fe, Mg and Au) alloy systems by first principles molecular dynamics simulation
复制标题
第一原理分子动力学模拟液态二元M-Si（M=Al、Fe、Mg、Au）合金体系的自扩散系数
DOI：
10.1063/1.5067295
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发表时间：
2019
期刊：
影响因子：
1.6
通讯作者：
Pan Shaopeng
中科院分区：
文献类型：
--
作者：
Qin Jingyu;Li Xinxin;Wang Jin;Pan Shaopeng
通过第一性原理分子动力学模拟，得到了相同过热温度下，五种元素在四种液态二元M-Si（M=Al，Fe，Mg，Au）合金体系中的自扩散系数。除DFe外，其余四种元素的自扩散系数随Si浓度（cSi）的变化规律都很明显。Si和M元素的混合焓决定了富Si区DSi-cSi曲线的斜率。影响DSi的主要因素是NSiSi的偏配位数，NSiSi越大，DSi越小。影响DSi的次要因素是液态合金中的中程有序：中程有序越强，DSi越小。在这些液态二元合金中，观察到自扩散系数耦合或解耦的复杂行为。
Through first-principles molecular dynamics simulation, the self-diffusion coefficients of five elements in the four liquid binary M-Si (M=Al,Fe,Mg,Au) alloy systems are obtained under the same overheating temperature. Except for DFe, the self-diffusion coefficient of the other four elements vary significantly with concentration of Si (cSi). The mixing enthalpy between Si and M elements determines the slop of DSi vs cSi curves in Si-rich range. The dominant factor on DSi is the partial coordination number of NSiSi: the larger the NSiSi is, the smaller DSi becomes. The secondary factor on DSi is the medium-range order in liquid alloys: the stronger the medium-range order is, the smaller DSi will be. Complex behavior of coupling or decoupling of self-diffusion coefficients in these liquid binary alloys are observed.