--- _id: '4178' abstract: - lang: eng text: "Exchange bias (EB) is a unidirectional anisotropy caused by interface coupling between a ferromagnet and an antiferromagnet. It causes a preferential direction of magnetization in the ferromagnet, which manifests as a shift of the hysteresis loop along the magnetic field axis. Here, we demonstrate a large EB of over 1000 Oe at 20 K in a twinned Co(111)/Co3O4(111) thin film epitaxially grown on sapphire(0001) with sixfold rotational lattice symmetry, which is among the highest values reported for Co/Co1−yO systems. In such systems, the effect intensity is largest along the magnetic easy axes, which usually results in an anisotropy of the EB in epitaxial interfaces. However, we observed identical EB values for 0°, 15°, and 30° angles between the magnetic field and the nearest Co[002] magnetic easy axes. The measurements imply a relaxation of the magnetization to the nearest easy axis, suggesting increasingly isotropic EB fields with higher orders of rotational lattice symmetry.\r\n " article_type: original author: - first_name: Martin full_name: Wortmann, Martin last_name: Wortmann - first_name: Tapas full_name: Samanta, Tapas last_name: Samanta - first_name: Maik full_name: Gaerner, Maik last_name: Gaerner - first_name: Michael full_name: Westphal, Michael last_name: Westphal - first_name: Johannes full_name: Fiedler, Johannes last_name: Fiedler - first_name: Inga full_name: Ennen, Inga last_name: Ennen - first_name: Andreas full_name: Hütten, Andreas last_name: Hütten - first_name: Tomasz full_name: Blachowicz, Tomasz last_name: Blachowicz - first_name: Luana full_name: Caron, Luana last_name: Caron - first_name: Andrea full_name: Ehrmann, Andrea id: '223776' last_name: Ehrmann orcid: 0000-0003-0695-3905 citation: alphadin: 'Wortmann, Martin ; Samanta, Tapas ; Gaerner, Maik ; Westphal, Michael ; Fiedler, Johannes ; Ennen, Inga ; Hütten, Andreas ; Blachowicz, Tomasz ; u. a.: Isotropic exchange-bias in twinned epitaxial Co/Co3O4 bilayer. In: APL Materials Bd. 11, AIP Publishing (2023), Nr. 12' ama: Wortmann M, Samanta T, Gaerner M, et al. Isotropic exchange-bias in twinned epitaxial Co/Co3O4 bilayer. APL Materials. 2023;11(12). doi:10.1063/5.0183566 apa: Wortmann, M., Samanta, T., Gaerner, M., Westphal, M., Fiedler, J., Ennen, I., … Ehrmann, A. (2023). Isotropic exchange-bias in twinned epitaxial Co/Co3O4 bilayer. APL Materials, 11(12). https://doi.org/10.1063/5.0183566 bibtex: '@article{Wortmann_Samanta_Gaerner_Westphal_Fiedler_Ennen_Hütten_Blachowicz_Caron_Ehrmann_2023, title={Isotropic exchange-bias in twinned epitaxial Co/Co3O4 bilayer}, volume={11}, DOI={10.1063/5.0183566}, number={12}, journal={APL Materials}, publisher={AIP Publishing}, author={Wortmann, Martin and Samanta, Tapas and Gaerner, Maik and Westphal, Michael and Fiedler, Johannes and Ennen, Inga and Hütten, Andreas and Blachowicz, Tomasz and Caron, Luana and Ehrmann, Andrea}, year={2023} }' chicago: Wortmann, Martin, Tapas Samanta, Maik Gaerner, Michael Westphal, Johannes Fiedler, Inga Ennen, Andreas Hütten, Tomasz Blachowicz, Luana Caron, and Andrea Ehrmann. “Isotropic Exchange-Bias in Twinned Epitaxial Co/Co3O4 Bilayer.” APL Materials 11, no. 12 (2023). https://doi.org/10.1063/5.0183566. ieee: M. Wortmann et al., “Isotropic exchange-bias in twinned epitaxial Co/Co3O4 bilayer,” APL Materials, vol. 11, no. 12, 2023. mla: Wortmann, Martin, et al. “Isotropic Exchange-Bias in Twinned Epitaxial Co/Co3O4 Bilayer.” APL Materials, vol. 11, no. 12, AIP Publishing, 2023, doi:10.1063/5.0183566. short: M. Wortmann, T. Samanta, M. Gaerner, M. Westphal, J. Fiedler, I. Ennen, A. Hütten, T. Blachowicz, L. Caron, A. Ehrmann, APL Materials 11 (2023). date_created: 2023-12-29T07:55:38Z date_updated: 2024-01-29T16:36:10Z doi: 10.1063/5.0183566 file: - access_level: open_access content_type: application/pdf creator: aehrmann date_created: 2023-12-29T07:53:14Z date_updated: 2023-12-29T07:53:14Z file_id: '4179' file_name: _2023_Wortmann_APL-Mater1_121118.pdf file_size: 9441825 relation: main_file success: 1 file_date_updated: 2023-12-29T07:53:14Z funded_apc: '1' has_accepted_license: '1' intvolume: ' 11' issue: '12' keyword: - Magnetic ordering - Crystallographic defects - Electron diffraction - Epitaxy - Ferromagnetic materials - Magnetic hysteresis - Magnetic materials - Thin films - Transmission electron microscopy - Solid solid interfaces language: - iso: eng main_file_link: - open_access: '1' oa: '1' publication: APL Materials publication_identifier: eissn: - 2166-532X publication_status: published publisher: AIP Publishing quality_controlled: '1' status: public title: Isotropic exchange-bias in twinned epitaxial Co/Co3O4 bilayer tmp: image: /images/cc_by.png legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0) short: CC BY (4.0) type: journal_article user_id: '220548' volume: 11 year: '2023' ... --- _id: '654' abstract: - lang: eng text: Magnetic nanofibers are of great interest in basic research, as well as for possible applications in spintronics and neuromorphic computing. Here we report on the preparation of magnetic nanofiber mats by electrospinning polyacrylonitrile (PAN)/nanoparticle solutions, creating a network of arbitrarily oriented nanofibers with a high aspect ratio. Since PAN is a typical precursor for carbon, the magnetic nanofiber mats were stabilized and carbonized after electrospinning. The magnetic properties of nanofiber mats containing magnetite or nickel ferrite nanoparticles were found to depend on the nanoparticle diameters and the potential after-treatment, as compared with raw nanofiber mats. Micromagnetic simulations underlined the different properties of both magnetic materials. Atomic force microscopy and scanning electron microscopy images revealed nearly unchanged morphologies after stabilization without mechanical fixation, which is in strong contrast to pure PAN nanofiber mats. While carbonization at 500 °C left the morphology unaltered, as compared with the stabilized samples, stronger connections between adjacent fibers were formed during carbonization at 800 °C, which may be supportive of magnetic data transmission. article_number: '1552' article_type: original author: - first_name: Nadine full_name: Fokin, Nadine last_name: Fokin - first_name: Timo full_name: Grothe, Timo id: '221330' last_name: Grothe orcid: 0000-0002-9099-4277 orcid_put_code_url: https://api.orcid.org/v2.0/0000-0002-9099-4277/work/94763644 - first_name: Al full_name: Mamun, Al last_name: Mamun - first_name: Marah full_name: Trabelsi, Marah last_name: Trabelsi - first_name: Michaela full_name: Klöcker, Michaela last_name: Klöcker - first_name: Lilia full_name: Sabantina, Lilia last_name: Sabantina - first_name: Christoph full_name: Döpke, Christoph last_name: Döpke - first_name: Tomasz full_name: Blachowicz, Tomasz last_name: Blachowicz - first_name: Andreas full_name: Hütten, Andreas last_name: Hütten - first_name: Andrea full_name: Ehrmann, Andrea id: '223776' last_name: Ehrmann orcid: 0000-0003-0695-3905 orcid_put_code_url: https://api.orcid.org/v2.0/0000-0003-0695-3905/work/94763646 citation: alphadin: 'Fokin, Nadine ; Grothe, Timo ; Mamun, Al ; Trabelsi, Marah ; Klöcker, Michaela ; Sabantina, Lilia ; Döpke, Christoph ; Blachowicz, Tomasz ; u. a.: Magnetic Properties of Electrospun Magnetic Nanofiber Mats after Stabilization and Carbonization. In: Materials Bd. 13 (2020), Nr. 7' ama: Fokin N, Grothe T, Mamun A, et al. Magnetic Properties of Electrospun Magnetic Nanofiber Mats after Stabilization and Carbonization. Materials. 2020;13(7). doi:10.3390/ma13071552 apa: Fokin, N., Grothe, T., Mamun, A., Trabelsi, M., Klöcker, M., Sabantina, L., … Ehrmann, A. (2020). Magnetic Properties of Electrospun Magnetic Nanofiber Mats after Stabilization and Carbonization. Materials, 13(7). https://doi.org/10.3390/ma13071552 bibtex: '@article{Fokin_Grothe_Mamun_Trabelsi_Klöcker_Sabantina_Döpke_Blachowicz_Hütten_Ehrmann_2020, title={Magnetic Properties of Electrospun Magnetic Nanofiber Mats after Stabilization and Carbonization}, volume={13}, DOI={10.3390/ma13071552}, number={71552}, journal={Materials}, author={Fokin, Nadine and Grothe, Timo and Mamun, Al and Trabelsi, Marah and Klöcker, Michaela and Sabantina, Lilia and Döpke, Christoph and Blachowicz, Tomasz and Hütten, Andreas and Ehrmann, Andrea}, year={2020} }' chicago: Fokin, Nadine, Timo Grothe, Al Mamun, Marah Trabelsi, Michaela Klöcker, Lilia Sabantina, Christoph Döpke, Tomasz Blachowicz, Andreas Hütten, and Andrea Ehrmann. “Magnetic Properties of Electrospun Magnetic Nanofiber Mats after Stabilization and Carbonization.” Materials 13, no. 7 (2020). https://doi.org/10.3390/ma13071552. ieee: N. Fokin et al., “Magnetic Properties of Electrospun Magnetic Nanofiber Mats after Stabilization and Carbonization,” Materials, vol. 13, no. 7, 2020. mla: Fokin, Nadine, et al. “Magnetic Properties of Electrospun Magnetic Nanofiber Mats after Stabilization and Carbonization.” Materials, vol. 13, no. 7, 1552, 2020, doi:10.3390/ma13071552. short: N. Fokin, T. Grothe, A. Mamun, M. Trabelsi, M. Klöcker, L. Sabantina, C. Döpke, T. Blachowicz, A. Hütten, A. Ehrmann, Materials 13 (2020). date_created: 2021-01-03T16:31:45Z date_updated: 2021-06-01T09:07:50Z department: - _id: '103' doi: 10.3390/ma13071552 file: - access_level: open_access content_type: application/pdf creator: aehrmann date_created: 2021-01-03T16:31:11Z date_updated: 2021-01-03T16:31:11Z file_id: '655' file_name: _2020_Fokin_materials13_1552_v2.pdf file_size: 5060954 relation: main_file success: 1 file_date_updated: 2021-01-03T16:31:11Z funded_apc: '1' has_accepted_license: '1' intvolume: ' 13' issue: '7' keyword: - ferrimagnetic materials - superparamagnetism - magnetic hysteresis - magnetic materials - magnetic nanoparticles - nanocomposites - nanowires language: - iso: eng oa: '1' publication: Materials publication_identifier: issn: - 1996-1944 publication_status: published quality_controlled: '1' status: public title: Magnetic Properties of Electrospun Magnetic Nanofiber Mats after Stabilization and Carbonization type: journal_article user_id: '237837' volume: 13 year: '2020' ...