TY - JOUR
T1 - Thermodynamic properties of the Nd-Bi system via emf measurements, DFT calculations, machine learning, and CALPHAD modeling
AU - Im, Sanghyeok
AU - Shang, Shun Li
AU - Smith, Nathan D.
AU - Krajewski, Adam M.
AU - Lichtenstein, Timothy
AU - Sun, Hui
AU - Bocklund, Brandon J.
AU - Liu, Zi Kui
AU - Kim, Hojong
N1 - Funding Information:
This work was supported by the U.S. Department of Energy (DOE) with Award No. DE-NE0008757 and the U.S. National Science Foundation (NSF) with Grant Nos. CBET-1844170 and CMMI-1825538 . BJB acknowledges the supports from a NASA Space Technology Research Fellowship (grant 90NSSC18K1168 ) and an NSF National Research Trainee Fellowship (grant DGE-1449785 ). First-principles calculations were performed partially on the Roar supercomputer at the Pennsylvania State University's Institute for Computational and Data Sciences (ICDS), partially on the resources of the National Energy Research Scientific Computing Center (NERSC) supported by the U.S. DOE under Contract No. DE-AC02–05CH11231 , and partially on the resources of the Extreme Science and Engineering Discovery Environment (XSEDE) supported by NSF with Grant No. ACI-1548562 .
Publisher Copyright:
© 2021 Acta Materialia Inc.
PY - 2022/1/15
Y1 - 2022/1/15
N2 - 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-NdCl3 at 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 NdBi2 was 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 Nd3Bi7 compound, invariant transition reactions, and liquidus temperatures.
AB - 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-NdCl3 at 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 NdBi2 was 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 Nd3Bi7 compound, invariant transition reactions, and liquidus temperatures.
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U2 - 10.1016/j.actamat.2021.117448
DO - 10.1016/j.actamat.2021.117448
M3 - Article
AN - SCOPUS:85119900630
SN - 1359-6454
VL - 223
JO - Acta Materialia
JF - Acta Materialia
M1 - 117448
ER -