Comparison of two calculation models for high entropy alloys: Virtual crystal approximation and special quasi-random structure

2021 ◽  
Vol 282 ◽  
pp. 128754
Author(s):  
Shen Wang ◽  
Jun Xiong ◽  
Da Li ◽  
Qiang Zeng ◽  
Min Xiong ◽  
...  
2017 ◽  
Vol 898 ◽  
pp. 611-621 ◽  
Author(s):  
Wen Qiang Feng ◽  
Shu Min Zheng ◽  
Yang Qi ◽  
Shao Qing Wang

Periodic chemically homogenized high-entropy alloy structures are constructed according to maximum entropy principle. The method can efficiently generate equimolar and non-equimolar high-entropy alloy atomic structures. Nine high-entropy alloys are simulated based on the constructed models using density functional theory techniques. The calculated lattice parameters are consistent with the available experimental data. The calculated enthalpies of mixing are more negative than the values estimated by using Miedema model, due to severe lattice distortion. The lattice distortion parameters were calculated. The results showed that fcc structure tend to stable with smaller and bcc structure with larger. The bulk modulus of Al1.5CoCrNiFe high-entropy alloys was fitted and the value is consistent with the available experimental data.


2019 ◽  
Author(s):  
Jack Pedersen ◽  
Thomas Batchelor ◽  
Alexander Bagger ◽  
Jan Rossmeisl

Using the high-entropy alloys (HEAs) CoCuGaNiZn and AgAuCuPdPt as starting points we provide a framework for tuning the composition of disordered multi-metallic alloys to control the selectivity and activity of the reduction of carbon dioxide (CO2) to highly reduced compounds. By combining density functional theory (DFT) with supervised machine learning we predicted the CO and hydrogen (H) adsorption energies of all surface sites on the (111) surface of the two HEAs. This allowed an optimization for the HEA compositions with increased likelihood for sites with weak hydrogen adsorption{to suppress the formation of molecular hydrogen (H2) and with strong CO adsorption to favor the reduction of CO. This led to the discovery of several disordered alloy catalyst candidates for which selectivity towards highly reduced carbon compounds is expected, as well as insights into the rational design of disordered alloy catalysts for the CO2 and CO reduction reaction.


2020 ◽  
Vol 2020 (4) ◽  
pp. 16-22
Author(s):  
A.I. Ustinov ◽  
◽  
V.S. Skorodzievskii ◽  
S.A. Demchenkov ◽  
S.S. Polishchuk ◽  
...  

2020 ◽  
Author(s):  
Yuan-Yuan Tan ◽  
Ming-Yao Su ◽  
Zhou-Can Xie ◽  
Zhong-Jun Chen ◽  
Yu Gong ◽  
...  

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