Zigzag-edge related ferromagnetism in MoSe2 nanoflakes.

Outstanding magnetic properties are highly desired for two-dimensional ultrathin semiconductor nanosheets for their potential applications in nano-electronics and spintronics. Here, ultrathin MoSe2 nanoflakes with plenty of edges were prepared via an efficient chemical vapor deposition method. The magnetic measurement results indicate that the sample exhibits strong ferromagnetic behaviour with a saturation magnetization of 1.4 emu g(-1) at room temperature, where the ferromagnetism persists up to 700 K, revealing the high Curie temperature of this material. Density functional theory spin-polarized calculations predict that strong ferromagnetic moments in MoSe2 nanoflakes are attributed to the zigzag edges. Our findings also suggest that the MoSe2 nanoflakes with a high density of edge spins could be used to fabricate spintronic devices, which are circuits utilizing the spin of the electron to process and store information.