Asymmetric Hysteresis Loops in Co Thin Films
Asymmetric magnetic hysteresis loops are usually found in exchange bias (EB) systems, typically after field cooling a system below the Néel temperature of an antiferromagnet exchange coupled to a ferromagnet. Alternatively, asymmetric hysteresis loops may occur due to undetected minor loops or in sy...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2020-11-01
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| Series: | Condensed Matter |
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| Online Access: | https://www.mdpi.com/2410-3896/5/4/71 |
| _version_ | 1827604688000778240 |
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| author | Andrea Ehrmann Tomasz Blachowicz |
| author_facet | Andrea Ehrmann Tomasz Blachowicz |
| author_sort | Andrea Ehrmann |
| collection | DOAJ |
| description | Asymmetric magnetic hysteresis loops are usually found in exchange bias (EB) systems, typically after field cooling a system below the Néel temperature of an antiferromagnet exchange coupled to a ferromagnet. Alternatively, asymmetric hysteresis loops may occur due to undetected minor loops or in systems with a rotational anisotropy. Here, we report on an exchange bias thin film system MgO(100)/Co/CoO, examined at room temperature, which is far above the blocking temperature, by the magneto-optical Kerr effect (MOKE). While the longitudinal hysteresis loops partly show steps which are well-known from diverse purely ferromagnetic systems, the transverse hysteresis loops exhibit clear asymmetries, similar to exchange biased systems at low temperatures, and unusual transverse magnetization values at saturation. Since minor loops and a rotational anisotropy can be excluded in this case, this asymmetry can possibly be a residue of the exchange bias coupling at lower temperatures. |
| first_indexed | 2024-03-09T06:04:43Z |
| format | Article |
| id | doaj.art-c5b2f3be71ae42c7bfd537287be0583a |
| institution | Directory Open Access Journal |
| issn | 2410-3896 |
| language | English |
| last_indexed | 2024-03-09T06:04:43Z |
| publishDate | 2020-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Condensed Matter |
| spelling | doaj.art-c5b2f3be71ae42c7bfd537287be0583a2023-12-03T12:05:28ZengMDPI AGCondensed Matter2410-38962020-11-01547110.3390/condmat5040071Asymmetric Hysteresis Loops in Co Thin FilmsAndrea Ehrmann0Tomasz Blachowicz1Faculty of Engineering and Mathematics, Bielefeld University of Applied Sciences, Interaction 1, 33619 Bielefeld, GermanyInstitute of Physics—Center for Science and Education, Silesian University of Technology, ul. Konarskiego 22B, 44-100 Gliwice, PolandAsymmetric magnetic hysteresis loops are usually found in exchange bias (EB) systems, typically after field cooling a system below the Néel temperature of an antiferromagnet exchange coupled to a ferromagnet. Alternatively, asymmetric hysteresis loops may occur due to undetected minor loops or in systems with a rotational anisotropy. Here, we report on an exchange bias thin film system MgO(100)/Co/CoO, examined at room temperature, which is far above the blocking temperature, by the magneto-optical Kerr effect (MOKE). While the longitudinal hysteresis loops partly show steps which are well-known from diverse purely ferromagnetic systems, the transverse hysteresis loops exhibit clear asymmetries, similar to exchange biased systems at low temperatures, and unusual transverse magnetization values at saturation. Since minor loops and a rotational anisotropy can be excluded in this case, this asymmetry can possibly be a residue of the exchange bias coupling at lower temperatures.https://www.mdpi.com/2410-3896/5/4/71exchange biasrotatable anisotropyblocking temperatureminor loopsCo/CoO |
| spellingShingle | Andrea Ehrmann Tomasz Blachowicz Asymmetric Hysteresis Loops in Co Thin Films Condensed Matter exchange bias rotatable anisotropy blocking temperature minor loops Co/CoO |
| title | Asymmetric Hysteresis Loops in Co Thin Films |
| title_full | Asymmetric Hysteresis Loops in Co Thin Films |
| title_fullStr | Asymmetric Hysteresis Loops in Co Thin Films |
| title_full_unstemmed | Asymmetric Hysteresis Loops in Co Thin Films |
| title_short | Asymmetric Hysteresis Loops in Co Thin Films |
| title_sort | asymmetric hysteresis loops in co thin films |
| topic | exchange bias rotatable anisotropy blocking temperature minor loops Co/CoO |
| url | https://www.mdpi.com/2410-3896/5/4/71 |
| work_keys_str_mv | AT andreaehrmann asymmetrichysteresisloopsincothinfilms AT tomaszblachowicz asymmetrichysteresisloopsincothinfilms |