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 (similar to 0.3 mu (B)/Co) around T-C = 175 K, followed by another magnetic anomaly around T-A approximate to 140 K. A large intrinsic anomalous Hall effect is observed in the magnetic state below T-C with a maximum of anomalous Hall angle near T-A. 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 T-C, and as it is further strengthened below T-A, it becomes nonmonotonic against the field between T-A and T-C 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.