Spatially periodic domain wall pinning potentials: Asymmetric pinning and dipolar biasing

Metaxas, P.J. et al. (2013) Spatially periodic domain wall pinning potentials: Asymmetric pinning and dipolar biasing. Journal of Applied Physics, 113(7), 073906. (doi: 10.1063/1.4792216)

Abstract

Domain wall propagation has been measured in continuous, weakly disordered, quasi-two-dimensional, Ising-like magnetic layers that are subject to spatially periodic domain wall pinning potentials. The potentials are generated non-destructively using the stray magnetic field of ordered arrays of magnetically hard [Co/Pt]m nanoplatelets, which are patterned above and are physically separated from the continuous magnetic layer. The effect of the periodic pinning potentials on thermally activated domain wall creep dynamics is shown to be equivalent, at first approximation, to that of a uniform, effective retardation field, Hret, which acts against the applied field, H. We show that Hret depends not only on the array geometry but also on the relative orientation of H and the magnetization of the nanoplatelets. A result of the latter dependence is that wall-mediated hysteresis loops obtained for a set nanoplatelet magnetization exhibit many properties that are normally associated with ferromagnet/antiferromagnet exchange bias systems. These include a switchable bias, coercivity enhancement, and domain wall roughness that is dependent on the applied field polarity.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Stamps, Professor Robert
• Authors: Metaxas, P.J., Zermatten, P.-J., Novak, R.L., Rohart, S., Jamet, J.-P., Weil, R., Ferré, J., Mougin, A., Stamps, R. L., Gaudin, G., Baltz, V., and Rodmacq, B.
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Journal Name: Journal of Applied Physics
• Publisher: American Institute of Physics
• ISSN: 0021-8979
• ISSN (Online): 1089-7550
• Copyright Holders: Copyright © 2013 American Institute of Physics
• First Published: First published in Journal of Applied Physics 113(7):073906
• Publisher Policy: Reproduced in accordance with the copyright policy of the publisher.