posted on 2024-02-24, 00:03authored byYuxuan Zhang, Teng Xu, Wanjun Jiang, Rong Yu, Zhen Chen
Noncolinear
spin textures, including chiral stripes and skyrmions,
have shown great potential in spintronics. Basic configurations of
spin textures are either Bloch or Néel types, and the intermediate
hybrid type has rarely been reported. A major challenge in identifying
hybrid spin textures is to quantitatively determine the hybrid angle,
especially in ferrimagnets with weak net magnetization. Here, we develop
an approach to quantify magnetic parameters, including chirality,
saturation magnetization, domain wall width, and hybrid angle with
sub-5 nm spatial resolution, based on Lorentz four-dimensional scanning
transmission electron microscopy (Lorentz 4D-STEM). We find strong
nanometer-scale variations in the hybrid angle and domain wall width
within structurally and chemically homogeneous FeGd ferrimagnetic
films. These variations fluctuate during different magnetization circles,
revealing intrinsic local magnetization inhomogeneities. Furthermore,
hybrid skyrmions can also be nucleated in FeGd films. These analyses
demonstrate that the Lorentz 4D-STEM is a quantitative tool for exploring
complex spin textures.