Magnetic Domain Structure Within Half-Metallic Ferromagnetic Kagome Compound Co3sn2s2

Co(3)Sn(2)S(2 )has been attracting attention as a model quasi-2D kagome ferromagnet as well as a ferromagnetic Weyl semimetal. Here, we report the evolution of the magnetic domain within Co3Sn2S2 as a function of temperature and external field as studied by in situ Lorentz microscopy. The domain structure typical for anisotropy-controlled material was observed, and domain wall (DW) motion was found to depend strongly on temperature. It was inactive due to strong pinning in a low-temperature range yet activated as a result of thermal depinning with increasing temperature. The activation temperature decreased as the external field increased. In the temperature range just below the Curie temperature, spontaneous domain reorganization associated with DW creep occurred even in the absence of an external field. The low-field anomalous magnetic phase just below the Curie temperature and split between zero-field-cooled and field-cooled magnetization-temperature curves found in our previous study [M. A. Kassem et al., Phys. Rev. B 96, 014429 (2017)] are explained in terms of temperature-dependent DW motion including the DW creep.