Magnetic properties of the layered magnetic topological insulator EuSn2As2

EuSn2As2 with a layered rhombohedral crystal structure is proposed to be a candidate for an intrinsic antiferromagnetic (AFM) topological insulator. Here, we have investigated systematic magnetoresistance (MR) and magnetization measurements on the high-quality EuSn2As2 single crystal with the magnetic field both parallel and perpendicular to the (001) plane. Both the kink of magnetic susceptibility and longitudinal resistivity reveal that EuSn2As2 undergoes an AFM transition at T-N = 21 K. At T = 2 K, the magnetization exhibits two successive plateaus of similar to 5.6 and similar to 6.6 mu(B)/Eu at the corresponding critical magnetic fields. Combined with the negative longitudinal MR and abnormal Hall resistance, we demonstrate that EuSn2As2 undergoes complicated magnetic transitions from an AFM state to a canted ferromagnetic (FM) state at H-c and then to a polarized FM state at H-s as the magnetic field increases.