  We report on the formation process of skyrmion lattice (SkL) domain
boundaries in FeGe using Lorentz transmission electron microscopy and
small-angle electron diffraction. We observed that grain boundaries and edges
play an important role in the formation of SkL domain boundaries; The SkL
domain boundary is stabilized at the intersection of two grains. A
micromagnetic simulation using the Landau-Lifshitz-Gilbert equation revealed
that the SkL domains separated by a boundary represent the lowest energy
configuration. Conversely, in a wide area, SkL domain boundaries were not
formed and SkL domains with different orientations rotated to form a single SkL
domain.
