Controlled synthesis and excellent magnetism of ferrimagnetic NiFe2Se4 nanostructures

ABSTRACT 3d transition metal chalcogenides have attracted much attention due to their unique magnetic properties. Although various Cr, V, and Fe-based chalcogenides have been fabricated recently, the limited Curie temperature ( T C ) still hinders their practical application. Based on the structural and magnetic advantages of MFe 2 O 4 and Fe 3 Se 4 , we developed a one-pot solution synthesis method for the fabrication of NiFe 2 Se 4 nanostructures with structural continuity, to facilitate the investigation of their magnetic properties. Notably, the morphology of NiFe 2 Se 4 can be controlled from nano-rods to nano-platelets by controlling the growth direction. The coercivity ( H C ) of NiFe 2 Se 4 with nano-cactus structure exhibits a maximum of 12.77 kOe at 5 K. The coercivity of ferrimagnetic NiFe 2 Se 4 nano-platelets can be further adjusted to 1.52 kOe at room temperature. These results show that the magnetic properties of NiFe 2 Se 4 can be significantly modified by controlling their morphologies. We also extend the method to the synthesis of CoFe 2 Se 4 nano-cactus with an ultrahigh coercivity of 17.85 kOe at 5 K. Obviously, the synthesis strategy and their excellent magnetic properties of MFe 2 Se 4 have sparked interest in ternary transition metal selenides as potential hard magnetic materials.