Figure 2. Lorentz transmission electron microscopy (LTEM) of skyrmion crystal.

(a,b) LTEM image at 283 K on (111) plane of Co₈Zn₈Mn₄ taken with under-focused condition at H=0 and 400 Oe, respectively. (c–f) LTEM image at 345 K on (110) plane of Co₈Zn₁₀Mn₂ taken with under-focused condition obtained at (c) H=0 and (d) 650 Oe, and (f) with over-focused condition at H=650 Oe. In c, the dark band running diagonally across the image is the diffraction contrast and not of magnetic origin. (e) Colour map of in-plane components of the magnetic induction (which reflects in-plane magnetization) at H=650 Oe deduced from TIE analysis of the images (d) and (f). (a–f) Scale bars, 200 nm. (g) Observed convergent-beam electron diffraction (CBED) pattern of Co₈Zn₁₀Mn₂ taken with the [111] incidence from the same specimen area where the LTEM images (c–f) were obtained. (h,i) Simulated CBED patterns assuming the space group No. 213 (P4₁32) and No. 212 (P4₃32), respectively. (j–l), (m–o) and (p–r) are magnified images for the selected areas (surrounded by blue, red and green dotted rectangles) of g,h and i, respectively. (k) is based on another picture with different exposure time for the purpose of avoiding intensity saturation. Characteristic structures to be compared between experimental result and simulations are indicated by blue and red triangles in j–r. Magnified images of the simulated pattern show significant differences for each crystal chirality. The simulated CBED pattern using P4₁32 (see m–o) shows a good agreement with the experimental one (see j–l).