Anisotropic magnetoelastic response in the magnetic Weyl semimetal Co3Sn2S2

Co3Sn2S2 is a recently identified magnetic Weyl semimetal in Shandite compounds. Upon cooling, Co3Sn2S2 undergoes a ferromagnetic transition with c-axis polarized moments (∼0.3 µB/Co) around TC = 175 K, followed by another magnetic anomaly around TA ≈ 140 K. A large intrinsic anomalous Hall effect is observed in the magnetic state below TC with a maximum of anomalous Hall angle near TA. Here, we report an elastic neutron scattering on the crystalline lattice of Co3Sn2S2 in a magnetic field up to 10 T. A strongly anisotropic magnetoelastic response is observed-while only a slight enhancement of the Bragg peaks is observed when B//c. The in-plane magnetic field (B//ab) dramatically suppresses the Bragg peak intensity probably by tilting the moments and lattice toward the external field direction. The in-plane magnetoelastic response commences from TC, and as it is further strengthened below TA, it becomes nonmonotonic against the field between TA and TC because of the competition from another in-plane magnetic order. These results suggest that a magnetic field can be employed to tune the Co3Sn2S2 lattice and its related topological states.