Canted standing spin-wave modes of permalloy thin films observed by ferromagnetic resonance
Non-collinear spin structures in materials that combine perpendicular and in-plane magnetic anisotropies are of great technological interest for microwave and spin wave-assisted magnetization switching. [Co/Pt] multilayers are well-known perpendicular anisotropy materials that have the potential to...
| Main Authors: | , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2021-01-01
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| Series: | New Journal of Physics |
| Subjects: | |
| Online Access: | https://doi.org/10.1088/1367-2630/abdd6b |
| _version_ | 1797750169784025088 |
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| author | Maciej Dąbrowski Robert J Hicken Andreas Frisk David G Newman Christoph Klewe Alpha T N’Diaye Padraic Shafer Gerrit van der Laan Thorsten Hesjedal Graham J Bowden |
| author_facet | Maciej Dąbrowski Robert J Hicken Andreas Frisk David G Newman Christoph Klewe Alpha T N’Diaye Padraic Shafer Gerrit van der Laan Thorsten Hesjedal Graham J Bowden |
| author_sort | Maciej Dąbrowski |
| collection | DOAJ |
| description | Non-collinear spin structures in materials that combine perpendicular and in-plane magnetic anisotropies are of great technological interest for microwave and spin wave-assisted magnetization switching. [Co/Pt] multilayers are well-known perpendicular anisotropy materials that have the potential to pin the magnetization of a soft magnetic layer, such as permalloy (Py), that has in-plane anisotropy, thereby forming a magnetic exchange spring. Here we report on multilayered [Co/Pt]/Pt/Py films, where an additional ultrathin Pt spacer has been included to control the coupling between the sub-units with in-plane and perpendicular magnetic anisotropy. Vector network analyser (VNA)-ferromagnetic resonance (FMR) measurements were made to obtain a complete picture of the resonant conditions, while the dynamical response of the sub-units was probed by synchrotron-based element- and phase selective x-ray detected FMR (XFMR). For all samples, only slight pinning of the dynamic magnetization of the Py by the [Co/Pt] was noted, and the FMR results were dominated by the 50 nm thick Py layer. Out-of-plane VNA-FMR maps reveal the presence of additional modes, e.g. a perpendicular standing spin-wave (PSSW) state. However, as the magnetic field is reduced below the saturation field, the PSSW state morphs continuously through a series of canted standing spin-wave (CSSW) states into a horizontal standing spin-wave (HSSW) state. The PSSW, CSSW and HSSW states are well described using a multilayer model of the Py film. The observation of CSSW modes is of particular relevance to microwave assisted magnetic recording, where microwave excitation stimulates precession of a soft layer canted out of plane by a pulsed magnetic field. |
| first_indexed | 2024-03-12T16:29:49Z |
| format | Article |
| id | doaj.art-ccc547ce874548d196b3f8ef283f5396 |
| institution | Directory Open Access Journal |
| issn | 1367-2630 |
| language | English |
| last_indexed | 2024-03-12T16:29:49Z |
| publishDate | 2021-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | New Journal of Physics |
| spelling | doaj.art-ccc547ce874548d196b3f8ef283f53962023-08-08T15:34:30ZengIOP PublishingNew Journal of Physics1367-26302021-01-0123202301710.1088/1367-2630/abdd6bCanted standing spin-wave modes of permalloy thin films observed by ferromagnetic resonanceMaciej Dąbrowski0https://orcid.org/0000-0002-6033-5721Robert J Hicken1Andreas Frisk2https://orcid.org/0000-0001-9234-0907David G Newman3https://orcid.org/0000-0002-4076-0288Christoph Klewe4Alpha T N’Diaye5Padraic Shafer6Gerrit van der Laan7Thorsten Hesjedal8https://orcid.org/0000-0001-7947-3692Graham J Bowden9Department of Physics and Astronomy, University of Exeter , Stocker Road, EX4 4QL, United KingdomDepartment of Physics and Astronomy, University of Exeter , Stocker Road, EX4 4QL, United KingdomDiamond Light Source, Harwell Science and Innovation Campus , Didcot, OX11 0DE, United KingdomDepartment of Physics and Astronomy, University of Exeter , Stocker Road, EX4 4QL, United KingdomAdvanced Light Source, Lawrence Berkeley National Laboratory , Berkeley, 94720, United States of AmericaAdvanced Light Source, Lawrence Berkeley National Laboratory , Berkeley, 94720, United States of AmericaAdvanced Light Source, Lawrence Berkeley National Laboratory , Berkeley, 94720, United States of AmericaDiamond Light Source, Harwell Science and Innovation Campus , Didcot, OX11 0DE, United KingdomDepartment of Physics, Clarendon Laboratory, University of Oxford , OX1 3PU, United KingdomSchool of Physics and Astronomy, University of Southampton , SO17 1BJ, United KingdomNon-collinear spin structures in materials that combine perpendicular and in-plane magnetic anisotropies are of great technological interest for microwave and spin wave-assisted magnetization switching. [Co/Pt] multilayers are well-known perpendicular anisotropy materials that have the potential to pin the magnetization of a soft magnetic layer, such as permalloy (Py), that has in-plane anisotropy, thereby forming a magnetic exchange spring. Here we report on multilayered [Co/Pt]/Pt/Py films, where an additional ultrathin Pt spacer has been included to control the coupling between the sub-units with in-plane and perpendicular magnetic anisotropy. Vector network analyser (VNA)-ferromagnetic resonance (FMR) measurements were made to obtain a complete picture of the resonant conditions, while the dynamical response of the sub-units was probed by synchrotron-based element- and phase selective x-ray detected FMR (XFMR). For all samples, only slight pinning of the dynamic magnetization of the Py by the [Co/Pt] was noted, and the FMR results were dominated by the 50 nm thick Py layer. Out-of-plane VNA-FMR maps reveal the presence of additional modes, e.g. a perpendicular standing spin-wave (PSSW) state. However, as the magnetic field is reduced below the saturation field, the PSSW state morphs continuously through a series of canted standing spin-wave (CSSW) states into a horizontal standing spin-wave (HSSW) state. The PSSW, CSSW and HSSW states are well described using a multilayer model of the Py film. The observation of CSSW modes is of particular relevance to microwave assisted magnetic recording, where microwave excitation stimulates precession of a soft layer canted out of plane by a pulsed magnetic field.https://doi.org/10.1088/1367-2630/abdd6bferromagnetic resonancestanding spin wavesXFMRcanted magnetizationexchange spring magnet |
| spellingShingle | Maciej Dąbrowski Robert J Hicken Andreas Frisk David G Newman Christoph Klewe Alpha T N’Diaye Padraic Shafer Gerrit van der Laan Thorsten Hesjedal Graham J Bowden Canted standing spin-wave modes of permalloy thin films observed by ferromagnetic resonance New Journal of Physics ferromagnetic resonance standing spin waves XFMR canted magnetization exchange spring magnet |
| title | Canted standing spin-wave modes of permalloy thin films observed by ferromagnetic resonance |
| title_full | Canted standing spin-wave modes of permalloy thin films observed by ferromagnetic resonance |
| title_fullStr | Canted standing spin-wave modes of permalloy thin films observed by ferromagnetic resonance |
| title_full_unstemmed | Canted standing spin-wave modes of permalloy thin films observed by ferromagnetic resonance |
| title_short | Canted standing spin-wave modes of permalloy thin films observed by ferromagnetic resonance |
| title_sort | canted standing spin wave modes of permalloy thin films observed by ferromagnetic resonance |
| topic | ferromagnetic resonance standing spin waves XFMR canted magnetization exchange spring magnet |
| url | https://doi.org/10.1088/1367-2630/abdd6b |
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