Magnetic transition behavior and large topological Hall effect in hexagonal Mn2−xFe1+xSn (x = 0.1) magnet

The magnetic transition, transport properties, and magnetic domain structures of the polycrystalline Mn1.9Fe1.1Sn compound with a hexagonal structure have been investigated. The result shows that ferromagnetic and antiferromagnetic phases coexist in this compound. A large topological Hall effect up to 3.5 μΩ·cm at 50 K has been found due to the formation of noncoplanar spin structures when the competition occurs among magnetocrystalline anisotropy, antiferromagnetic coupling, and ferromagnetic interaction at low temperature. The result of in situ Lorentz transmission electron microscopy cooling experiment at zero field indicates two shapes of domain walls containing vortexes coexisting simultaneously in the compound.