Twin domains in epitaxial thin MnSi layers on Si(111)

Thin layers of MnSi, the first discovered host material of a skyrmion lattice, are epitaxially grown on Si(111) and their crystal properties are investigated by X-ray diffraction and transmission electron microscopy (TEM) measurements. Azimuthal $ϕ$-scans of asymmetric X-ray reflections reveal the formation of twinned domains with their unit cell rotated $±30°$ in plane with respect to the Si unit cell. The intensities of corresponding reflections indicate the same volume fractions for both domain types. Cross-sectional TEM confirms the presence of these domains and reveals a typical domain size of about 200 nm.