A1 Vertaisarvioitu alkuperäisartikkeli tieteellisessä lehdessä
First-principles study on segregation anisotropy of grain boundaries in Pt–Au alloys
Tekijät: Yao, Xin; Guo, Ya-Fang; Li, Wei; Kokko, Kalevi; Li, Changle; Vitos, Levente
Kustantaja: AIP Publishing
Kustannuspaikka: MELVILLE
Julkaisuvuosi: 2025
Journal: Journal of Applied Physics
Tietokannassa oleva lehden nimi: Journal of Applied Physics
Lehden akronyymi: J APPL PHYS
Artikkelin numero: 055107
Vuosikerta: 137
Numero: 5
Sivujen määrä: 15
ISSN: 0021-8979
eISSN: 1089-7550
DOI: https://doi.org/10.1063/5.0238622
Verkko-osoite: https://doi.org/10.1063/5.0238622
Rinnakkaistallenteen osoite: https://research.utu.fi/converis/portal/detail/Publication/491324976
Gold (Au) segregation at the Pt grain boundaries (GBs) plays an important role on the properties of Pt-based alloys. It was reported that the close-packed GBs and the open GBs exhibit different segregation behaviors, and the origin of which is still unclear. Based on density functional theory (DFT) as implemented in the exact muffin-tin orbitals method (EMTO) and the full charge density technique, we investigate the impact of bulk composition and temperature on the segregation behaviors of the Sigma 3(111)[1-10] , Sigma 5(310)[001] and Sigma 9(221)[1-10] symmetric tilt GBs in Pt-Au alloys. It is revealed that the segregation driving forces are correlated with the large local volume near the GB and the miscibility gap in Pt-Au alloys. At finite temperatures when the configurational entropy is considered, a competition between the chemical driving force and the configurational entropy is responsible for the segregation anisotropy in Pt-Au alloys. Moreover, the bulk composition has a small effect on the segregation energy, but strongly impacts the equilibrium concentration profiles at finite temperatures.The present study provides a theoretical analysis for the segregation anisotropy, and the methodology ultilized in this work can be generalized to other binary or multi-component dilute or concentrated alloys while the composition variation is involved. (c) 2025 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International (CC BY-NC-ND) license (https://creativecommons.org/licenses/by-nc-nd/4.0/).
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This work was supported by the National Natural Science Foundation of China (NNSFC) (No. 12172038), the Scientific and Technological Project of Yunnan Precious Metals Laboratory (YPML-20240502034), and the China Scholarship Council. The calculations were performed on resources provided by the National Academic Infrastructure for Supercomputing in Sweden (NAISS) at the National Supercomputer Centre (NSC) in Linköping through Grant Agreement No. 2024-5-10. X.Y. acknowledges Song Lu and Ziyi Xiong for their guidance. L.V., C.L., and W.L. acknowledge the Swedish Research Council, Swedish Foundation for Strategic Research, the Hungarian Scientific Research Fund (OTKA Grant No. 128229), the Carl Tryggers Foundation (Grant Nos. 19:325 and 20:474), and the Formas—a Swedish Research Council for Sustainable Development (Grant No. 2023-00543).
