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.