Iunin Y L, Kabanov Y P, Nikitenko V I, Cheng X M, Clarke D, Tretiakov O A, Tchernyshyov O, Shapiro A J, Shull R D, Chien C L
Institute of Solid State Physics, Russian Academy of Sciences, Chernogolovka 142432, Russia.
Phys Rev Lett. 2007 Mar 16;98(11):117204. doi: 10.1103/PhysRevLett.98.117204.
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.
我们报道了具有垂直各向异性的超薄钴膜和钴/铂多层膜在磁化反转过程中出现的意外现象。利用磁光克尔显微镜和磁力显微镜，我们观察到了不对称的成核中心，其中反转仅在磁场的一个方向开始，其特征是畴壁迁移率存在严重不对称。我们还观察到了平均磁化强度不断变化的磁畴，这可以用三种磁相（向上、向下和条纹状）共存来解释。
