Bloch Lines Constituting Antiskyrmions Captured via Differential Phase Contrast
Fehmi Sami Yasin, Licong Peng, R. Takagi, Naoya Kanazawa, S. Seki, Yoshinori Tokura, Xiuzhen Yu
Abstract
Abstract Much scientific capital has been directed toward exotic magnetic spin textures called Bloch lines, that is, Néel‐type line boundaries within domain walls, because their geometry promises high‐density magnetic storage. While predicted to arise in high‐anisotropy magnets, bulk soft magnets, and thin films with in‐plane magnetization, Bloch lines also constitute magnetic antiskyrmions, that is, topological antiparticles of skyrmions. Most domain walls occur as Bloch‐type or Néel‐type, in which the magnetization rotates parallel or perpendicular to the domain wall across its profile, respectively. The Bloch lines’ Néel‐type rotation and their minute size make them difficult to directly measure. This work utilizes differential phase contrast (DPC) scanning transmission electron microscopy (STEM) to measure the in‐plane magnetization of Bloch lines within antiskyrmions emergent in a non‐centrosymmetric Heusler magnet with D 2d symmetry, Mn 1.4 Pt 0.9 Pd 0.1 Sn, in addition to Bloch‐type skyrmions in an FeGe magnet with B20‐type crystal structure to benchmark the DPC technique. Both in‐focus measurement and identification of Bloch lines at the antiskyrmion's corners are provided.