Room-temperature ferromagnetic CoSe2nanoplates synthesized by chemical vapor deposition.

Among novel two-dimensional materials, transition metal dichalcogenides (TMDs) with 3dmagnetic elements have been extensively researched owing to their unique magnetic, electric, and photoelectric properties. As an important member of TMDs, CoSe2is an interesting material with controversial magnetic properties, hitherto there are few reports related to the magnetism of CoSe2materials. Here, we report the synthesis of CoSe2nanoplates on Al2O3substrates by chemical vapor deposition (CVD). The CVD-grown CoSe2nanoplates exhibit three typical morphologies (regular hexagonal, hexagonal, and pentagonal shapes) and their lateral sizes and thickness of CoSe2nanoplates can reach up to hundreds of microns and several hundred nanometers, respectively. The electric-transport measurement shows a metallic feature of CoSe2nanoplates. Furthermore, the slanted hysteresis loop and nonzero remnant magnetization of the CoSe2nanoplates confirm the ferromagnetism in the temperature range of 5-400 K. This work provides a novel platform for designing CoSe2-based spintronic devices and studying related magnetic mechanisms.