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 µ_B/Co) around T_C = 175 K, followed by another magnetic anomaly around T_A ≈ 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. [ABSTRACT FROM AUTHOR]