Thickness-induced reversal of magnetoresistance polarity in CoFeNi-based MTJs: evolution from coherent switching to vortex-state transport.
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| Title: | Thickness-induced reversal of magnetoresistance polarity in CoFeNi-based MTJs: evolution from coherent switching to vortex-state transport. |
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| Authors: | Gayathri, S. Vimala1 (AUTHOR), Subbulekshmi, D.1 (AUTHOR) subbulekshmi.d@vit.ac.in, Kennedy, L. John2 (AUTHOR) |
| Source: | Journal of Materials Science. Apr2026, Vol. 61 Issue 13, p8644-8663. 20p. |
| Subjects: | Tunnel magnetoresistance, Magnetization reversal, Spintronics, Magnetoresistance, Cobalt nickel alloys, Magnetization, Magnetic tunnelling |
| Abstract: | Magnetic Tunnel Junctions (MTJs) operate on the principle of spin-dependent tunneling through an ultrathin insulating barrier, and their magnetoresistive response depends on the relative alignment of magnetization within the two ferromagnetic layers. In this work, the free-layer thickness controls the magnetization states and magnetotransport behavior of CoFeNi/MgO/CoFeNi MTJs by means of micromagnetic simulations. The findings show a clear transition in thickness from coherent single-domain rotation towards vortex-mediated reversal. This transition, in turn, directly controls the Tunneling Magnetoresistance (TMR) observed to change in polarity from +199% at 25 nm to −344% at 100 nm. The coercive field moderately increases from 22.3 mT to 24.9 mT as a function of thickness, which attests to the transition between uniform and non-collinear magnetization configurations. Thus, the polarity inversion in sign arises from the formation of vortex states at larger thicknesses, which create non-collinear interfacial spin alignments and enhanced spin-flip tunneling, resulting in the reversal of the effective spin polarization. The research provides systematic insights into the thickness-dependent magnetic configurations, energy landscapes, and transport behavior in CoFeNi-based MTJs, with conclusions important for further prospective memory and logic devices. [ABSTRACT FROM AUTHOR] |
| Copyright of Journal of Materials Science is the property of Springer Nature and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Engineering Source |
| FullText | Text: Availability: 0 |
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| Header | DbId: egs DbLabel: Engineering Source An: 192202441 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: Thickness-induced reversal of magnetoresistance polarity in CoFeNi-based MTJs: evolution from coherent switching to vortex-state transport. – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Gayathri%2C+S%2E+Vimala%22">Gayathri, S. Vimala</searchLink><relatesTo>1</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Subbulekshmi%2C+D%2E%22">Subbulekshmi, D.</searchLink><relatesTo>1</relatesTo> (AUTHOR)<i> subbulekshmi.d@vit.ac.in</i><br /><searchLink fieldCode="AR" term="%22Kennedy%2C+L%2E+John%22">Kennedy, L. John</searchLink><relatesTo>2</relatesTo> (AUTHOR) – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Journal+of+Materials+Science%22">Journal of Materials Science</searchLink>. Apr2026, Vol. 61 Issue 13, p8644-8663. 20p. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Tunnel+magnetoresistance%22">Tunnel magnetoresistance</searchLink><br /><searchLink fieldCode="DE" term="%22Magnetization+reversal%22">Magnetization reversal</searchLink><br /><searchLink fieldCode="DE" term="%22Spintronics%22">Spintronics</searchLink><br /><searchLink fieldCode="DE" term="%22Magnetoresistance%22">Magnetoresistance</searchLink><br /><searchLink fieldCode="DE" term="%22Cobalt+nickel+alloys%22">Cobalt nickel alloys</searchLink><br /><searchLink fieldCode="DE" term="%22Magnetization%22">Magnetization</searchLink><br /><searchLink fieldCode="DE" term="%22Magnetic+tunnelling%22">Magnetic tunnelling</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: Magnetic Tunnel Junctions (MTJs) operate on the principle of spin-dependent tunneling through an ultrathin insulating barrier, and their magnetoresistive response depends on the relative alignment of magnetization within the two ferromagnetic layers. In this work, the free-layer thickness controls the magnetization states and magnetotransport behavior of CoFeNi/MgO/CoFeNi MTJs by means of micromagnetic simulations. The findings show a clear transition in thickness from coherent single-domain rotation towards vortex-mediated reversal. This transition, in turn, directly controls the Tunneling Magnetoresistance (TMR) observed to change in polarity from +199% at 25 nm to −344% at 100 nm. The coercive field moderately increases from 22.3 mT to 24.9 mT as a function of thickness, which attests to the transition between uniform and non-collinear magnetization configurations. Thus, the polarity inversion in sign arises from the formation of vortex states at larger thicknesses, which create non-collinear interfacial spin alignments and enhanced spin-flip tunneling, resulting in the reversal of the effective spin polarization. The research provides systematic insights into the thickness-dependent magnetic configurations, energy landscapes, and transport behavior in CoFeNi-based MTJs, with conclusions important for further prospective memory and logic devices. [ABSTRACT FROM AUTHOR] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of Journal of Materials Science is the property of Springer Nature and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.) |
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| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1007/s10853-026-12339-1 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 20 StartPage: 8644 Subjects: – SubjectFull: Tunnel magnetoresistance Type: general – SubjectFull: Magnetization reversal Type: general – SubjectFull: Spintronics Type: general – SubjectFull: Magnetoresistance Type: general – SubjectFull: Cobalt nickel alloys Type: general – SubjectFull: Magnetization Type: general – SubjectFull: Magnetic tunnelling Type: general Titles: – TitleFull: Thickness-induced reversal of magnetoresistance polarity in CoFeNi-based MTJs: evolution from coherent switching to vortex-state transport. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Gayathri, S. Vimala – PersonEntity: Name: NameFull: Subbulekshmi, D. – PersonEntity: Name: NameFull: Kennedy, L. John IsPartOfRelationships: – BibEntity: Dates: – D: 01 M: 04 Text: Apr2026 Type: published Y: 2026 Identifiers: – Type: issn-print Value: 00222461 Numbering: – Type: volume Value: 61 – Type: issue Value: 13 Titles: – TitleFull: Journal of Materials Science Type: main |
| ResultId | 1 |
