Anisotropy-induced depinning in the Zn-substituted skyrmion host Cu2OSeO3
Birch, M.T.; Moody, S.H.; Wilson, M.N.; Crisanti, M.; Bewley, O.; Štefančič, A.; Balakrishnan, G.; Fan, R.; Steadman, P.; Alba Venero, D.; Cubitt, R.; Hatton, P.D.
Mr Samuel Harrison Moody email@example.com
PGR Student Doctor of Philosophy
D. Alba Venero
Professor Peter Hatton firstname.lastname@example.org
Magnetic skyrmions are nanosized topological spin textures stabilized by a delicate balance of magnetic energy terms. The chemical substitution of the underlying crystal structure of skyrmion-hosting materials offers a route to manipulate these energy contributions but also introduces additional effects such as disorder and pinning. While the effects of doping and disorder have been well studied in B20 metallic materials such as Fe1−xCoxSi and Mn1−xFexSi, the consequences of chemical substitution in the magnetoelectric insulator Cu2OSeO3 have not been fully explored. In this work we utilize a combination of AC magnetometry and small-angle neutron scattering to investigate the magnetic phase transition dynamics in pristine and Zn-substituted Cu2OSeO3. The results demonstrate that the first-order helical-conical phase transition exhibits two thermally separated behavioral regimes: at high temperatures, the helical and conical domains transform by large-scale, continuous rotations, while at low temperatures, the two phases coexist. Remarkably, the effects of pinning in the substituted sample are less prevalent at low temperatures compared to high temperatures, despite the reduction of available thermal activation energy. We attribute this behavior to the large, temperature-dependent, cubic anisotropy unique to Cu2OSeO3, which becomes strong enough to overcome the pinning energy at low temperatures. Consideration and further exploration of these effects will be crucial when engineering skyrmion materials towards future applications.
Birch, M., Moody, S., Wilson, M., Crisanti, M., Bewley, O., Štefančič, A., …Hatton, P. (2020). Anisotropy-induced depinning in the Zn-substituted skyrmion host Cu2OSeO3. Physical review B, 102(10), Article 104424. https://doi.org/10.1103/physrevb.102.104424
|Journal Article Type||Article|
|Acceptance Date||Sep 2, 2020|
|Online Publication Date||Sep 18, 2020|
|Deposit Date||Oct 7, 2020|
|Publicly Available Date||Oct 7, 2020|
|Journal||Physical Review B|
|Publisher||American Physical Society|
|Peer Reviewed||Peer Reviewed|
Published Journal Article
Reprinted with permission from the American Physical Society: Birch, M. T., Moody, S. H., Wilson, M. N., Crisanti, M., Bewley, O., Štefančič, A., Balakrishnan, G., Fan, R., Steadman, P., Alba Venero, D., Cubitt, R. & Hatton, P. D. (2020). Anisotropy-induced depinning in the Zn-substituted skyrmion host Cu2OSeO3. Physical Review B 102(10): 104424 © 2020 by the American Physical Society. Readers may view, browse, and/or download material for temporary copying purposes only, provided these uses are for noncommercial personal purposes. Except as provided by law, this material may not be further reproduced, distributed, transmitted, modified, adapted, performed, displayed, published, or sold in whole or part, without prior written permission from the American Physical Society.
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