Strain-Tuned Ferroelectric Transitions in HfO2: Role of X2- Mode in Ferroelectric Instabilities

Strain-Tuned Ferroelectric Transitions in HfO2: Role of X2- Mode in Ferroelectric Instabilities | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Strain-Tuned Ferroelectric Transitions in HfO 2 : Role of X 2 - Mode in Ferroelectric Instabilities ilyoung Lee, jaejun Yu, Wontae Lee This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6191974/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Recent studies have identified HfO 2 as a promising ferroelectric material for thin films, highlighting its potential as a state-of-the-art option for future ferroelectric applications. However, due to the complexity of the fabrication process, the underlying mechanism of the phase transition to Pca2 1 is still not fully understood. In this study, we aim to clarify the phase transition pathway by investigating the formation of the ferroelectric Pca2 1 phase via strain and symmetry-allowed phonon mode instability. Our results reveal that applying tensile strain regardless of direction induces an 𝑋 2 - mode displacement, initiating a primary phase transition and consequently inducing instability in the polar and antipolar modes. Furthermore, the coupling between the single distortion modes andthe 𝑋 2 - modelowers the trilinear mode barrier, ultimately triggering a secondary phase transition that leads to the O phase. These findings suggest that optimizing substrate conditions to enhance the displacement of the 𝑋 2 - mode is critical to achieve robust ferroelectric properties. Our insights into substrate engineering provide a foundation for the practical realization of ferroelectricity in device applications. Hard Condensed-matter Physics Computational Physics Phase transition Ferroeletric phonon mode Full Text Additional Declarations The authors declare no competing interests. Supplementary Files Supplementarymaterial.pdf Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-6191974","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":426748739,"identity":"48ebd724-7725-4fe5-97b4-fc8b4ab3115c","order_by":0,"name":"ilyoung 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Ferroelectric Instabilities\u003c/p\u003e","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"National Research Foundation of Korea","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Phase transition, Ferroeletric, phonon mode","lastPublishedDoi":"10.21203/rs.3.rs-6191974/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6191974/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eRecent studies have identified HfO\u003csub\u003e2\u003c/sub\u003e as a promising ferroelectric material for thin films, highlighting its \u0026nbsp;potential as a state-of-the-art option for future ferroelectric applications. However, due to the complexity of the \u0026nbsp;fabrication process, the underlying mechanism of the phase transition to Pca2\u003csub\u003e1\u003c/sub\u003e is still not fully understood. In \u0026nbsp;this study, we aim to clarify the phase transition pathway by investigating the formation of the ferroelectric Pca2\u003csub\u003e1\u003c/sub\u003e \u0026nbsp;phase via strain and symmetry-allowed phonon mode instability. Our results reveal that applying tensile strain \u0026nbsp;regardless of direction induces an 𝑋\u003csub\u003e2\u003c/sub\u003e\u003csup\u003e-\u003c/sup\u003e mode displacement, initiating a primary phase transition and consequently \u0026nbsp;inducing instability in the polar and antipolar modes. Furthermore, the coupling between the single distortion \u0026nbsp;modes andthe 𝑋\u003csub\u003e2\u003c/sub\u003e\u003csup\u003e-\u003c/sup\u003e modelowers the trilinear mode barrier, ultimately triggering a secondary phase transition that \u0026nbsp;leads to the O phase. These findings suggest that optimizing substrate conditions to enhance the displacement \u0026nbsp;of the 𝑋\u003csub\u003e2\u003c/sub\u003e\u003csup\u003e-\u003c/sup\u003e \u0026nbsp;mode is critical to achieve robust ferroelectric properties. Our insights into substrate engineering \u0026nbsp;provide a foundation for the practical realization of ferroelectricity in device applications.\u003c/p\u003e","manuscriptTitle":"Strain-Tuned Ferroelectric Transitions in HfO2: Role of X2- Mode in Ferroelectric Instabilities","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-03-12 05:07:07","doi":"10.21203/rs.3.rs-6191974/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"558264b6-0e58-4840-bf07-90b37a98754e","owner":[],"postedDate":"March 12th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":45469967,"name":"Hard Condensed-matter Physics"},{"id":45469968,"name":"Computational Physics"}],"tags":[],"updatedAt":"2025-03-12T05:07:07+00:00","versionOfRecord":[],"versionCreatedAt":"2025-03-12 05:07:07","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-6191974","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6191974","identity":"rs-6191974","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}