Thermodynamic properties of the Nd-Bi system via emf measurements, DFT calculations, machine learning, and CALPHAD modeling
Thermodynamic properties of the Nd-Bi system via emf measurements, DFT calculations, machine learning, and CALPHAD modeling
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DOI：
10.1016/j.actamat.2021.117448
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发表时间：
2021-10
期刊：
影响因子：
9.4
通讯作者：
Sang-Moo Im;S. Shang;N. Smith;Adam M Krajewski;T. Lichtenstein;Hui Sun;B. Bocklund;Zi-kui Liu;Hojong Kim
中科院分区：
文献类型：
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作者：
Sang-Moo Im;S. Shang;N. Smith;Adam M Krajewski;T. Lichtenstein;Hui Sun;B. Bocklund;Zi-kui Liu;Hojong Kim
通过实验测量、基于密度泛函理论（DFT）的第一性原理计算、数据挖掘和机器学习（DM + ML）预测以及相图计算（CALPHAD）建模，研究了Nd-Bi体系的热力学性质。采用库仑滴定法测定了773-973 K下熔融licl - kcl - ndcl3中Nd-Bi合金的电动势（emf），以测定Nd在Bi中的活度系数和溶解度等热化学性质。用差示扫描量热法、结构（x射线衍射）和显微结构（扫描电镜）分析证实了[液体+ NdBi2= Nd3Bi7]在774 K下发生了新的包晶反应。基于对26000多个ab2型结构的ML预测以及基于dft的验证，未知的ndbi2晶体结构被认为是反la2sb型结构和la2te型结构的混合物。利用新获得的实验数据和基于dft的计算，重构了Nd-Bi体系的热力学描述，并计算了一个更完整的Nd-Bi相图，包括nd3bi7化合物、不变转变反应和液相温度。
Thermodynamic properties of the Nd-Bi system were investigated using a combination of experimental measurements, first-principles calculations based on density functional theory (DFT), data mining and machine learning (DM + ML) predictions, and calculation of phase diagrams (CALPHAD) modeling. The electromotive force (emf) of Nd-Bi alloys in molten LiCl-KCl-NdCl3at 773–973 K was measured via coulometric titration of Nd into Bi for the determination of thermochemical properties such as activity coefficients and solubilities of Nd in Bi. A new peritectic reaction of [liquid + NdBi2= Nd3Bi7] at 774 K was confirmed using differential scanning calorimetry, structural (X-ray diffraction), and microstructural (scanning electron microscopy) analyses. The unknown crystal structure of NdBi2was suggested to be a mixture of the anti-La2Sb configuration and the La2Te-type configuration based on ML predictions for over 26,000 data-mined AB2-type configurations together with DFT-based verifications. Using the newly acquired experimental data and DFT-based calculations, the thermodynamic description of the Nd-Bi system was remodeled, and a more complete Nd-Bi phase diagram was calculated, including the Nd3Bi7compound, invariant transition reactions, and liquidus temperatures.