Low-field anomalous magnetic phase in the kagome-lattice shandite Co3Sn2S2

Abstract: The magnetization process of single crystals of the metallic kagom\'e ferromagnet Co3Sn2S2 was carefully measured via magnetization and AC susceptibility. Field-dependent anomalous transitions in the magnetization indicate a low-field unconventionally ordered phase stabilized just below TC. The magnetic phase diagrams in applied fields along different crystallographic directions were determined. The magnetic relaxation process studied in frequencies covering five orders of magnitude from 0.01 to 1000 Hz indicates characteristic relaxation times of several seconds at the boarders of the anomalous phase. Our results arise a lot of questions about the nature of Co3Sn2S2 magnetic states.