Physical Review Letters
We report unexpected phenomena during magnetization reversal in ultrathin Co films and Co/Pt multilayers with perpendicular anisotropy. Using magneto-optical Kerr microscopy and magnetic force microscopy we have observed asymmetrical nucleation centers where the reversal begins for one direction of the field only and is characterized by an acute asymmetry of domain-wall mobility. We have also observed magnetic domains with a continuously varying average magnetization, which can be explained in terms of the coexistence of three magnetic phases: up, down, and striped.
© 2007 by the American Physical Society. The publisher's version of the article can be found at http://prl.aps.org/abstract/PRL/v98/i11/e117204.
Y. L. Iunin et al., Phys. Rev. Lett. 98, 117204 (2007).