Origin of Semiconductor–Metal–Semiconductor-Like Transition in LaFeO3

Origin of Semiconductor–Metal–Semiconductor-Like Transition in LaFeO3 | 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 Origin of Semiconductor–Metal–Semiconductor-Like Transition in LaFeO 3 Sandeep Kumar, Sesh mani Yadav, Satish Kumar Yadav, Poonam Yadav, and 8 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7804000/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 A comprehensive investigation of the semiconductor–metal–semiconductor-like transition (SMST) in LaFeO 3 nanoceramics, synthesized via a modified sol-gel auto-combustion method, was conducted at low temperatures. Scanning electron microscopy (SEM) of the fracture surface reveals a porous microstructure with an average grain size of approximately 60 nm. X-ray photoelectron spectroscopy (XPS) confirms the presence of Fe 2+ , Fe 3+ , and Fe 4+ ions and oxygen vacancies in the LaFeO 3 matrix. Impedance analysis indicates that the observed SMST behavior is associated with valence state transitions among Fe + 3 , Fe + 2 , and Fe + 4 ions. The Kohlrausch-Williams-Watts (KWW) parameter is less than unity, suggesting non-Debye-type relaxation, as supported by modulus spectroscopy. The temperature-dependent frequency exponent indicates that the conduction mechanism is governed by both correlated barrier hopping (CBH) and non-overlapping small polaron tunnelling (NSPT). A high dielectric constant in the low-frequency region confirms the dominant contribution of electrode polarization. Moreover, the temperature-dependent dielectric constant and tangent loss further validate the SMST behavior. Materials Chemistry Modified sol-gel auto-combustion route Lanthanum orthoferrite Maximum entropy method Semiconductor-metal-semiconductor transition non-Debye type relaxation Full Text Additional Declarations The authors declare potential competing interests as follows: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. 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. 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","formattedTitle":"\u003cp\u003e\u003cstrong\u003eOrigin of Semiconductor–Metal–Semiconductor-Like Transition in LaFeO\u003c/strong\u003e\u003csub\u003e\u003cstrong\u003e3\u003c/strong\u003e\u003c/sub\u003e\u003c/p\u003e","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"","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":"Modified sol-gel auto-combustion route, Lanthanum orthoferrite, Maximum entropy method, Semiconductor-metal-semiconductor transition, non-Debye type relaxation","lastPublishedDoi":"10.21203/rs.3.rs-7804000/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7804000/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eA comprehensive investigation of the semiconductor\u0026ndash;metal\u0026ndash;semiconductor-like transition (SMST) in LaFeO\u003csub\u003e3\u003c/sub\u003e nanoceramics, synthesized via a modified sol-gel auto-combustion method, was conducted at low temperatures. Scanning electron microscopy (SEM) of the fracture surface reveals a porous microstructure with an average grain size of approximately 60 nm. X-ray photoelectron spectroscopy (XPS) confirms the presence of Fe\u003csup\u003e2+\u003c/sup\u003e, Fe\u003csup\u003e3+\u003c/sup\u003e, and Fe\u003csup\u003e4+\u003c/sup\u003e ions and oxygen vacancies in the LaFeO\u003csub\u003e3\u003c/sub\u003e matrix. Impedance analysis indicates that the observed SMST behavior is associated with valence state transitions among Fe\u003csup\u003e+\u0026thinsp;3\u003c/sup\u003e, Fe\u003csup\u003e+\u0026thinsp;2\u003c/sup\u003e, and Fe\u003csup\u003e+\u0026thinsp;4\u003c/sup\u003e ions. The Kohlrausch-Williams-Watts (KWW) parameter is less than unity, suggesting non-Debye-type relaxation, as supported by modulus spectroscopy. The temperature-dependent frequency exponent indicates that the conduction mechanism is governed by both correlated barrier hopping (CBH) and non-overlapping small polaron tunnelling (NSPT). A high dielectric constant in the low-frequency region confirms the dominant contribution of electrode polarization. Moreover, the temperature-dependent dielectric constant and tangent loss further validate the SMST behavior.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e","manuscriptTitle":"Origin of Semiconductor–Metal–Semiconductor-Like Transition in LaFeO3","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-10-09 03:12:39","doi":"10.21203/rs.3.rs-7804000/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":"73bbe4be-97dd-4a9c-b746-0b14cfc5eeda","owner":[],"postedDate":"October 9th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":55937797,"name":"Materials Chemistry"}],"tags":[],"updatedAt":"2025-10-09T03:12:39+00:00","versionOfRecord":[],"versionCreatedAt":"2025-10-09 03:12:39","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7804000","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7804000","identity":"rs-7804000","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}