Kuepper K, Wintz S, Raabe J, Buess M, Akhmadaliev Ch, Bischoff L, Quitmann C, Fassbender J
Institut für Festkörperphysik, University of Ulm, Albert-Einstein-Allee 11, D-89069 Ulm, GermanyPresent address.
J Phys Condens Matter. 2009 Oct 28;21(43):436003. doi: 10.1088/0953-8984/21/43/436003. Epub 2009 Oct 8.
Magnetic vortex cores are interacting with and can even be annihilated by artificial defects, such as holes. These defects have been fabricated by focused ion beam milling (FIB) into the magnetic domains, domain walls and the center of square-shaped vortices, known as Landau structures. We report the imaging of the magnetization dynamics of Landau structures containing holes by means of x-ray magnetic circular dichroism photo-emission electron microscopy (XMCD-PEEM). Due to the high lateral and temporal resolution of this method, the magnetic excitation spectrum, which is characteristic for the vortex-hole interaction, is investigated in detail. We find that the vortex core as well as domain walls can be trapped by small holes. With the help of micromagnetic simulations we show that the vortex gyrotropic motion frequency is enhanced, whereas the amplitude is significantly reduced in the case of non-centric holes in domain walls.
磁涡旋核会与诸如孔洞等人工缺陷相互作用，甚至会被其湮灭。这些缺陷是通过聚焦离子束铣削（FIB）制造在磁畴、畴壁以及方形涡旋中心（即朗道结构）中的。我们报告了借助X射线磁圆二色性光发射电子显微镜（XMCD-PEEM）对含有孔洞的朗道结构的磁化动力学进行成像的研究。由于该方法具有高横向和时间分辨率，因此对涡旋 - 孔洞相互作用所特有的磁激发光谱进行了详细研究。我们发现涡旋核以及畴壁会被小孔捕获。借助微磁模拟，我们表明在畴壁中存在非中心孔洞的情况下，涡旋回转运动频率会增强，而振幅会显著降低。
