Ferromagnetic semiconductor nanotubes with room Curie temperatures

Abstract Realizing ferromagnetic semiconductors with high Curie temperature T C remains a challenge in spintronics. Recent experiments have obtained some two-dimensional (2D) room temperature ferromagnetic metals, such as monolayers CrS2 and VSe2. Inspired by the recent experimental progress on the nanotubes based on 2D van der Waals non-magnetic transition-metal dichalcogenides, magnetic nanotubes based on monolayer ferromagnetic materials are highly possible. Here, by the density functional theory calculations, we proposed a way to obtain a high T C ferromagnetic semiconductor in magnetic nanotubes. Some high T C ferromagnetic semiconductors are predicted in the MX2 nanotubes (M = V, Cr, Mn, Fe, Co, Ni; X = S, Se, Te), including CrS2 and CrTe2 zigzag nanotubes with a diameter of 18 unit cells, showing T C above 300 K. In addition, due to the strain gradient in the walls of nanotubes, an electrical polarization at the level of 0.1 eV/Å inward of the radial direction is obtained. Our results propose a way to obtain high-temperature ferromagnetic semiconducting nanotubes based on experimentally obtained 2D high T C ferromagnetic metals.