---
_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'
...