Driving force of atomic ordering in Fe-Pt alloys, investigated by density functional theory and machine-learning interatomic potentials Monte Carlo simulations.
{"title":"Driving force of atomic ordering in Fe-Pt alloys, investigated by density functional theory and machine-learning interatomic potentials Monte Carlo simulations.","authors":"Tomoyuki Tsuyama, Takeshi Kaneshita, Akira Matsui, Kohei Ochiai, Hiroaki Tanaka, Ryohei Kondo, Takayuki Fukushima, Haruhisa Ohashi, Atsushi Hashimoto, Yoshishige Okuno, Jian-Gang Zhu","doi":"10.1088/1361-648X/adbba5","DOIUrl":null,"url":null,"abstract":"<p><p>We report the mechanisms of atomic ordering in Fe-Pt bimetallic alloys using density functional theory (DFT) and machine-learning interatomic potential Monte Carlo (MLIP-MC) simulations. We clarified that the formation enthalpy of the ordered phase was significantly enhanced by spin polarization compared to that of the disordered phase. Analysis of the density of states indicated that coherence in local potentials in the ordered phase brings energy gain over the disordered phase, when spin is considered. MLIP-MC simulations were performed to investigate the phase transition of atomic ordering at finite temperatures. The model trained using the DFT dataset with spin polarization exhibited quantitatively good agreement with previous experiments and thermodynamic calculations across a wide range of Pt compositions. In contrast, the model without spin significantly underestimated the transition temperature. Through this study, we clarified that spin polarization is essential for accurately accounting for the ordered phase in Fe-Pt bimetallic alloys, even above the Curie temperature, possibly because of the remaining short-range spin order.</p>","PeriodicalId":16776,"journal":{"name":"Journal of Physics: Condensed Matter","volume":" ","pages":""},"PeriodicalIF":2.3000,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Physics: Condensed Matter","FirstCategoryId":"101","ListUrlMain":"https://doi.org/10.1088/1361-648X/adbba5","RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"PHYSICS, CONDENSED MATTER","Score":null,"Total":0}
引用次数: 0
Abstract
We report the mechanisms of atomic ordering in Fe-Pt bimetallic alloys using density functional theory (DFT) and machine-learning interatomic potential Monte Carlo (MLIP-MC) simulations. We clarified that the formation enthalpy of the ordered phase was significantly enhanced by spin polarization compared to that of the disordered phase. Analysis of the density of states indicated that coherence in local potentials in the ordered phase brings energy gain over the disordered phase, when spin is considered. MLIP-MC simulations were performed to investigate the phase transition of atomic ordering at finite temperatures. The model trained using the DFT dataset with spin polarization exhibited quantitatively good agreement with previous experiments and thermodynamic calculations across a wide range of Pt compositions. In contrast, the model without spin significantly underestimated the transition temperature. Through this study, we clarified that spin polarization is essential for accurately accounting for the ordered phase in Fe-Pt bimetallic alloys, even above the Curie temperature, possibly because of the remaining short-range spin order.
期刊介绍:
Journal of Physics: Condensed Matter covers the whole of condensed matter physics including soft condensed matter and nanostructures. Papers may report experimental, theoretical and simulation studies. Note that papers must contain fundamental condensed matter science: papers reporting methods of materials preparation or properties of materials without novel condensed matter content will not be accepted.