Toward ferromagnetic semimetal ground state with multiple Weyl nodes in van der Waals crystal MnSb4Te7

The magnetic topological van der Waals materials family MnBi2Te4/(Bi2Te3)( n ) have drawn markedly attention due to their novel multiple topological phases in different magnetic configurations. Recently, their close relative, the MnSb4Te7, was firstly synthesized in experiments (2021 Phys. Rev. Lett. 126 246601). To further explore the emergent properties of MnSb4Te7, we have systematically investigated the magnetic and topological characters under compressive strain and charge doping using first-principles calculations. We predict that MnSb4Te7 transits from an interlayer antiferromagnetic ground state to a ferromagnetic semimetal ground state with multiple Weyl points when compressive strained along c axis above 8% or charge doping before 0.1 hole/formula concentration. Notable anomalous Hall conductivity is also predicted. Meanwhile, the magnetic easy axis can be reoriented from out-of-plane to in-plane orientation when strain or electron doping is applied. The underlying magnetic exchange mechanism is also analyzed from our calculation results. Our work thus provides a feasible way to realize applications of the highly tunable magnetic-topological nature and a comprehensive theoretical understanding of this magnetic topological material.