Magneto-optical imaging of vortex domain deformation in pinning sites

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS

卷:381

Article

Badea, R.¹  Frey, J. A.¹  Berezovsky, J.¹ 

[1] Case Western Reserve Univ, Dept Phys, Cleveland, OH 44106 USA

关键词: Magnetic domains;    Pinning;    Kerr effect;   

DOI  :  10.1016/j.jmmm.2015.01.036

来源: Elsevier

【 摘 要 】

We use a sensitive magneto-optical microscopy technique to image the magnetization response of micron-scale ferromagnetic disks to changes in applied magnetic field. This differential technique relies on a modulated applied magnetic field which allows us to measure changes in magnetization <1% with submicron resolution. The disks are magnetized in single vortex domains, with defects in the material serving to pin the vortex core at particular positions. By applying a small AC magnetic field, we measure the deformation of the magnetization while the core remains pinned. We can also characterize the strength of the pinning site by increasing the AC magnetic field to unpin the vortex core. While pinned, we find that the magnetization away from the core reorients slightly to better align with an applied field. Additionally, an applied field causes the pinned core itself to tilt in the direction of the field. Once the field is large enough to unpin the core, this tilt disappears, and the core instead translates across the disk. (C) 2015 Elsevier B.V. All rights reserved

【 授权许可】

Free