Vivek Devulapalli, Enze Chen, Tobias Brink, Timofey Frolov, Christian H. Liebscher
{"title":"Topological grain boundary segregation transitions","authors":"Vivek Devulapalli, Enze Chen, Tobias Brink, Timofey Frolov, Christian H. Liebscher","doi":"arxiv-2405.08193","DOIUrl":null,"url":null,"abstract":"Engineering structure of grain boundaries (GBs) by solute segregation is a\npromising strategy to tailor the properties of polycrystalline materials.\nTheoretically it has been suggested that solute segregation can trigger phase\ntransitions at GBs offering novel pathways to design interfaces. However, an\nunderstanding of their intrinsic atomistic nature is missing. Here, we combine\natomic resolution electron microscopy atomistic simulations to discover that\niron segregation to GBs in titanium stabilizes icosahedral units (cages) that\nform robust building blocks of distinct GB phases. Due to their five-fold\nsymmetry, the Fe cages cluster and assemble into hierarchical GB phases\ncharacterised by a different number and arrangement of the constituent\nicosahedral units. Our advanced GB structure prediction algorithms and\natomistic simulations validate the stability of these observed phases and the\nhigh excess of Fe at the GB that is accommodated by the phase transitions.","PeriodicalId":501234,"journal":{"name":"arXiv - PHYS - Materials Science","volume":"8 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2024-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"arXiv - PHYS - Materials Science","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/arxiv-2405.08193","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
Engineering structure of grain boundaries (GBs) by solute segregation is a
promising strategy to tailor the properties of polycrystalline materials.
Theoretically it has been suggested that solute segregation can trigger phase
transitions at GBs offering novel pathways to design interfaces. However, an
understanding of their intrinsic atomistic nature is missing. Here, we combine
atomic resolution electron microscopy atomistic simulations to discover that
iron segregation to GBs in titanium stabilizes icosahedral units (cages) that
form robust building blocks of distinct GB phases. Due to their five-fold
symmetry, the Fe cages cluster and assemble into hierarchical GB phases
characterised by a different number and arrangement of the constituent
icosahedral units. Our advanced GB structure prediction algorithms and
atomistic simulations validate the stability of these observed phases and the
high excess of Fe at the GB that is accommodated by the phase transitions.