Above-Room-Temperature\nFerromagnetism Regulation in\nTwo-Dimensional Heterostructures by van der Waals Interfacial Magnetochemistry

Most methods for regulating physical and chemical properties\nof\nmaterials involve the breaking and formation of chemical bonds, which\ninevitably change local structures. Two-dimensional (2D) ferromagnets\nare critical for spintronic memory and quantum devices, but most of\nthem maintain ferromagnetism at low temperature, and multiaspect control\nof 2D ferromagnetism at room temperature or above is still missing.\nHere, we report a nondestructive, van der Waals (vdW) interfacial\nmagnetochemistry strategy for above-room-temperature, multiaspect\n2D ferromagnetism regulation. By vdW coupling nonmagnetic MoS<sub>2</sub>, WSe<sub>2</sub>, or Bi<sub>1.5</sub>Sb<sub>0.5</sub>Te<sub>1.7</sub>Se<sub>1.3</sub> with 2D vdW ferromagnet Fe<sub>3</sub>GaTe<sub>2</sub>, the Curie temperature is enhanced up to 400 K, best for\n2D ferromagnets, with 26.8% tuning of room-temperature perpendicular\nmagnetic anisotropy and an unconventional anomalous Hall effect up\nto 340 K. These phenomena originate from changes in magnetic exchange\ninteractions and magnetic anisotropy energy by interfacial charge\ntransfer and spin–orbit coupling. This work opens a pathway\nfor engineering multifunctional 2D heterostructures by vdW interfacial\nmagnetochemistry.