*

The Co-based shandite, Co₃Sn₂S₂, is a Weyl³ semi-metal hosting an itinerant ferromagnetic quasi-2D Kagomé lattice of Co ions. This system exhibits strong c-axis anisotropy with a curie temperature ~ 174 K and a spontaneous moment of ~ 0.3 μ_B/Co.² Low-field magnetization and AC susceptibility measurements have revealed an anomalous magnetic phase above ~ 126 K and below ~ 40 mT, indicating a possible skyrmion phase. To this end, we carried out variable-temperature magnetic force microscopy studies on Co₃Sn₂S₂ single crystals. MFM images under zero-field cooling revealed fingerprint-like magnetic domains, while low-field cooling through T_C resulted in seemingly periodic magnetic bubble domains, which is consistent with the quasi-2D nature of the magnetic ordering. Detailed temperature and cooling field dependence of the magnetic domain patterns will be presented.

²M. A. Kassem, et al., J. Phys. Soc. Jpn. 85, 064706 (2016).
³Q. Wang, et al., Nat. Comm. 9, 3681 (2018).