LAUSR

The combination of topological phase and intrinsic beyond-room-temperature ferromagnetism is expected to realize the quantum anomalous Hall effect at a high temperature. However, no beyond-room-temperature intrinsic ferromagnetism has been reported in either topological insulator or topological crystalline insulator (TCI) so far. Here, we report Cr-doping in TCI-phase SnTe crystals which possess highly tunable beyond-room-temperature intrinsic ferromagnetism including Tc, magnetic moment, and coercivity by varying Cr contents and crystal thickness. With the increase of the Cr content, the Tc increases by 159 K from 221 to 380 K and the saturation magnetic moments increase by ∼23.6 times from 0.018 to 0.421 μB/f.u. This intrinsic beyond-room-temperature ferromagnetism is fully demonstrated by the anomalous Hall effect and magneto-optical Kerr effect in a single CrxSn1-xTe nanosheet. Moreover, the room-temperature tunneling magnetoresistance effect has been realized by using a CrxSn1-xTe flake, a Fe thin film, and a commercially compatible ultrathin AlOx tunneling barrier. This work indicates a great potential of CrxSn1-xTe crystals in room-temperature magnetoelectronic and spintronic devices.