Observation of skyrmion-like magnetism in magnetic Weyl semimetal Co3Sn2S2

Polycrystalline samples Co3Sn2S2+x (0 ≤ x ≤ 0.34), (Co1-yNiy)3Sn2S2.26 (0 ≤ y ≤ 0.05), and (Co1-zFez)3Sn2S2.26 (0 ≤ z ≤ 0.05) were synthesized using a solid-state-reaction method and characterized by X-ray diffraction, electron probe microanalyzer, and magnetic measurements. Single crystal Co3Sn2S2 was also grown by self-flux method and analyzed by detailed magnetic measurements to study its isotropic nature. In this study, we reproduced the low magnetic field anomalous magnetism, as previously reported, with a negligible sample-dependent effect. Furthermore, based on ac magnetic susceptibility data, we established a H-T phase diagram including the skyrmion-like A phase of Co3Sn2S2. Both application of external high-pressure and chemical substitutions revealed anomalous magnetisms in low magnetic fields. The possible origin of the field-induced A phase can be the non-collinear skyrmion-like phenomenon. These interesting findings in Weyl semimetal Co3Sn2S2 provide a new candidate in spin-frustrated systems to explore the complexity of magnetic field–induced magnetism. [Display omitted] •Observations of the robustness of the low-field skyrmion-like A phase in kagome Co3Sn2S2.•With high pressure and chemical substitution, the significant evolution of magnetic H-T phase diagram is well-established.•These findings provide a new candidate to explore the complexity of magnetic field–induced magnetism.