Spin injection in graphene using ferromagnetic indium-cobalt van der Waals contacts

Spin injection in graphene using ferromagnetic indium-cobalt van der Waals contacts | 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 Spin injection in graphene using ferromagnetic indium-cobalt van der Waals contacts Soumya Sarkar, Saeyoung Oh, Peter J. Newton, Yang Li, Yiru Zhu, and 5 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4707068/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 Graphene based spintronic devices require efficient spin injection and collection. Oxide dielectric tunnel barriers obtained by direct deposition or oxidizing thin metal films are typically used to facilitate spin injection. However, the yield of working devices with such tunnel barriers is low (typically 5-10%) as direct growth of oxides on dangling bond free 2D surfaces is challenging. Here we report a robust and simple method for spin injection in graphene lateral spin valves (LSVs) using ferromagnetic (FM) van der Waals (vdW) contacts of indium and cobalt (In/Co) that does not require deposition of dielectric tunnel barriers. We obtain magnetoresistance (MR) values of 1.5 % + 0.5% (spin signal ~ 50 ohms) - comparable to state-of-the-art graphene LSVs with oxide tunnel barriers – with a working device yield of >70% with FM In/Co vdW contacts. In contrast, LSVs with contacts containing only Co are highly inefficient and in the best cases show an MR ~ 0.2% (spin signal ≤ 3 ohms, only 10% devices work). The contact resistance of FM In/Co vdW contacts is 2 – 5 kohms, making them compatible for integration with complementary metal oxide semiconductor devices for electrical switching. Our results promise facile and high yield fabrication of spintronic devices using direct deposition of In/Co vdW contacts. Full Text Additional Declarations The authors declare no competing interests. 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-4707068","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":324311255,"identity":"31ebd18d-3f3e-49f9-83fa-4d306405aa4b","order_by":0,"name":"Soumya Sarkar","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Soumya","middleName":"","lastName":"Sarkar","suffix":""},{"id":324311256,"identity":"ea92bb53-1428-4b89-a2bc-dc57d35115ee","order_by":1,"name":"Saeyoung Oh","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Saeyoung","middleName":"","lastName":"Oh","suffix":""},{"id":324311257,"identity":"d0386fd9-d62a-4d14-8361-c4cd247efc41","order_by":2,"name":"Peter J. Newton","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Peter","middleName":"J.","lastName":"Newton","suffix":""},{"id":324311258,"identity":"ca2c0f12-60a1-4e2c-ad26-6b026f9200dd","order_by":3,"name":"Yang Li","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Yang","middleName":"","lastName":"Li","suffix":""},{"id":324311259,"identity":"df2c9ebb-5a9c-4472-b5d2-144d017a5efa","order_by":4,"name":"Yiru Zhu","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Yiru","middleName":"","lastName":"Zhu","suffix":""},{"id":324311260,"identity":"b4d1d382-4a0e-4cc8-a2f5-905dd65c3564","order_by":5,"name":"Maheera Abdul Ghani","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Maheera","middleName":"Abdul","lastName":"Ghani","suffix":""},{"id":324311261,"identity":"601de0db-e2b0-4c92-974c-5c575b7f1764","order_by":6,"name":"Han Yan","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Han","middleName":"","lastName":"Yan","suffix":""},{"id":324311262,"identity":"c6a7ca4e-04ff-4acc-bd6f-40e52d5a52ab","order_by":7,"name":"Hu Young Jeong","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Hu","middleName":"Young","lastName":"Jeong","suffix":""},{"id":324311263,"identity":"79c3ebad-2fed-423e-a3f9-00e0ac36b6d2","order_by":8,"name":"Yan Wang","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Yan","middleName":"","lastName":"Wang","suffix":""},{"id":324311264,"identity":"19f075c8-299c-4b2f-8cb4-2e8a1ddf7206","order_by":9,"name":"Manish Chhowalla","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAt0lEQVRIiWNgGAWjYFAC5gMHPlTAeQnEaGFLfDjjDGlaeIyNedtI0aLbfsBMmneenbxuA/PDD4xtaYS1mJ1JSJOcuy3ZcNsBNmMJxrYcIrTcYDgm8XbbAcZtBxjMGBjbKojRwtgmwTvngP22A+zfiNXCzGzI23AgcdsBHpAtxDjsTBrjwxnHkpO3HeYplkg4R4z3j5//cOBDjZ3ttuPtGz98KEsmrAUBmBmIjMhRMApGwSgYBYQBALF5OyDO0YiuAAAAAElFTkSuQmCC","orcid":"","institution":"","correspondingAuthor":true,"prefix":"","firstName":"Manish","middleName":"","lastName":"Chhowalla","suffix":""}],"badges":[],"createdAt":"2024-07-08 16:50:03","currentVersionCode":1,"declarations":{"humanSubjects":false,"vertebrateSubjects":false,"conflictsOfInterestStatement":false,"humanSubjectEthicalGuidelines":false,"humanSubjectConsent":false,"humanSubjectClinicalTrial":false,"humanSubjectCaseReport":false,"vertebrateSubjectEthicalGuidelines":false},"doi":"10.21203/rs.3.rs-4707068/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4707068/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":59966799,"identity":"2134f077-6f4e-4d9a-8ab6-e81ed880012b","added_by":"auto","created_at":"2024-07-10 02:12:49","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1004083,"visible":true,"origin":"","legend":"","description":"","filename":"MainManuscriptR1unmarked.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4707068/v1_covered_1cdb4087-70b0-43a0-96d6-01e99a4190df.pdf"}],"financialInterests":"The authors declare no competing interests.","formattedTitle":"\u003cp\u003e\u003cstrong\u003eSpin injection in graphene using ferromagnetic indium-cobalt van der Waals contacts\u003c/strong\u003e\u003c/p\u003e","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"University of Cambridge","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":"","lastPublishedDoi":"10.21203/rs.3.rs-4707068/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4707068/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eGraphene based spintronic devices require efficient spin injection and collection. Oxide dielectric tunnel barriers obtained by direct deposition or oxidizing thin metal films are typically used to facilitate spin injection. However, the yield of working devices with such tunnel barriers is low (typically 5-10%) as direct growth of oxides on dangling bond free 2D surfaces is challenging. Here we report a robust and simple method for spin injection in graphene lateral spin valves (LSVs) using ferromagnetic (FM) van der Waals (vdW) contacts of indium and cobalt (In/Co) that does not require deposition of dielectric tunnel barriers. We obtain magnetoresistance (MR) values of 1.5 % \u003cu\u003e+\u003c/u\u003e 0.5% (spin signal ~ 50 ohms) - comparable to state-of-the-art graphene LSVs with oxide tunnel barriers – with a working device yield of \u0026gt;70% with FM In/Co vdW contacts. In contrast, LSVs with contacts containing only Co are highly inefficient and in the best cases show an MR ~ 0.2% (spin signal ≤ 3 ohms, only 10% devices work). The contact resistance of FM In/Co vdW contacts is 2 – 5 kohms, making them compatible for integration with complementary metal oxide semiconductor devices for electrical switching. Our results promise facile and high yield fabrication of spintronic devices using direct deposition of In/Co vdW contacts.\u003c/p\u003e","manuscriptTitle":"Spin injection in graphene using ferromagnetic indium-cobalt van der Waals contacts","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-07-10 02:04:42","doi":"10.21203/rs.3.rs-4707068/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":"01904325-645b-4257-9ce3-5de80cd13030","owner":[],"postedDate":"July 10th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2024-07-10T02:04:42+00:00","versionOfRecord":[],"versionCreatedAt":"2024-07-10 02:04:42","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-4707068","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4707068","identity":"rs-4707068","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}