Bi Doping-Induced Ferromagnetism of Layered Material SnSe2 with Extremely Large Coercivity

Abstract Ferromagnetism of two-dimensional layered materials is of considerable interest in spintronics. In the present work, we report the ferromagnetism of the layered material SnSe 2 induced by Bi doping. The pure SnSe 2 and Bi-doped SnSe 2 film samples are prepared by chemical vapor transport method. X-ray diffractions show that both the SnSe 2 and Bi-doped SnSe 2 have CdI 2 -type layered structure grown perfectly along the c -axis. Magnetic measurements indicate that the pure SnSe 2 is a diamagnet. The doping of nonmagnetic Bi introduces ferromagnetism in SnSe 2 with Curie temperature of 65 K. A coercivity as high as 4.4 kOe is observed at T  = 10 K. Such high coercivity has never been reported in d 0 two-dimensional layered materials. First-principles calculations indicate that the Bi-doping leads to the spin splitting of degenerate p x and p y orbital states and gives rise to a spin order aligned in ab plane. Calculations also show that the Bi-doped SnSe 2 is a half metal. All these features make Bi-doped SnSe 2 a potential candidate for spintronic material.