Strong roomerature ferromagnetism in VSe₂ monolayers on van der Waals substrates

Reduced dimensionality and interlayer coupling in van der Waals materials gives rise to fundamentally different electronic ¹, optical ² and many-body quantum ^3-5 properties in monolayers compared with the bulk. This layer-dependence permits the discovery of novel material properties in the monolayer regime. Ferromagnetic order in two-dimensional materials is a coveted property that would allow fundamental studies of spin behaviour in low dimensions and enable new spintronics applications ^6-8 . Recent studies have shown that for the bulk-ferromagnetic layered materials CrI₃ (ref. ⁹ ) and Cr₂Ge₂Te₆ (ref. ¹⁰ ), ferromagnetic order is maintained down to the ultrathin limit at low temperatures. Contrary to these observations, we report the emergence of strong ferromagnetic ordering for monolayer VSe₂, a material that is paramagnetic in the bulk ^11,12 . Importantly, the ferromagnetic ordering with a large magnetic moment persists to above room temperature, making VSe₂ an attractive material for van der Waals spintronics applications.