The domain structure of a MnSb 2 Te 4 single crystal with a Curie temperature of T C ≈ 45 K has been studied using the high-resolution Bitter decoration technique. Magnetotransport measurements have confirmed soft ferromagnetic ordering with a coercive field of about 100 Oe. The formation of a hierarchical domain structure characterized by two distinct spatial scales has been revealed. These results indicate the existence of weakly magnetically coupled surface and bulk subsystems. The observed subdomain structure can be attributed to the formation of a ferromagnetic barrier due to an inhomogeneous distribution of Mn Sb antisite defects with an additional contribution from symmetry breaking in the near-surface layer.
Tyutvinov et al. (Sun,) studied this question.