Vanhaverbeke A, Bischof A, Allenspach R
IBM Research, Zurich Research Laboratory, Säumerstrasse 4, CH-8803 Rüschlikon, Switzerland.
Phys Rev Lett. 2008 Sep 5;101(10):107202. doi: 10.1103/PhysRevLett.101.107202. Epub 2008 Sep 2.
Direct observation of current-induced propagation of purely transverse magnetic domain walls with spin-polarized scanning electron microscopy is reported in Fe30Ni70 nanowires. After propagation, the domain walls keep their transverse nature but switch polarity in some cases. For uniform Ni70Fe30 wires, the effect is random and illustrates domain-wall propagation above the Walker threshold. In the case of Ni{70}Fe_{30}/Fe wires, the transverse magnetization component in the wall is entirely determined by the polarity of the current pulse, an effect that is not reconciled by present theories even when taking into account the nonuniform Oersted field generated by the current.
在Fe30Ni70纳米线中，利用自旋极化扫描电子显微镜直接观察了电流诱导的纯横向磁畴壁的传播。传播后，磁畴壁保持其横向性质，但在某些情况下会改变极性。对于均匀的Ni70Fe30线，这种效应是随机的，表明磁畴壁在沃克阈值以上传播。在Ni{70}Fe_{30}/Fe线的情况下，壁中的横向磁化分量完全由电流脉冲的极性决定，即使考虑到电流产生的非均匀奥斯特场，目前的理论也无法解释这种效应。
