Title: Temperature-dependent magneto-optical measurement of ferromagnetic kagome-lattice semimetal Co₃Sn₂S₂

Co₃Sn₂S₂ is a Co-based shandite material with a ferromagnetic Curie temperature of around 175 K. The hexagonal lattice of the crystal forms a kagome network of Co atoms within the Co3Sn layer. The spin-up band crosses the Fermi level in the sample's band structure. We can create a ring structure by connecting the crossing points in 3D. This ring opens up more with spin-orbit interaction, resulting in a gap with anti-crossing lines. We studied temperature-dependent spin dynamics in ferromagnetic kagome-lattice semimetal Co₃Sn₂S₂ via ultrafast time-resolved magneto-optic Kerr effect(TR-MOKE) up to 7T.