Prediction of one-dimensional CrN nanostructure as a promising ferromagnetic half-metal

Abstract

Searching for one-dimensional (1D) nanostructure with ferromagnetic (FM) half-metallicity is of significance for the development of miniature spintronic devices. Here, based on the first-principles calculations, we propose that the 1D CrN nanostructure is a FM half-metal, which can generate the fully spin-polarized current. The ab initio molecular dynamic simulation and the phonon spectrum calculation demonstrate that the 1D CrN nanostructure is thermodynamically stable. The partially occupied Cr-d orbitals endow the nanostructure with FM half-metallicity, in which the half-metallic gap (Δs) reaches up to 1.58 eV. The ferromagnetism in the nanostructure is attributed to the superexchange interaction between the magnetic Cr atoms, and a sizable magnetocrystalline anisotropy energy (MAE) is obtained. Moreover, the transverse stretching of nanostructure can effectively modulate Δs and MAE, accompanied by the preservation of half-metallicity. A nanocable is designed by encapsulating the CrN nanostructure with a BN nanotube, and the intriguing magnetic and electronic properties of the nanostructure are retained. These novel characteristics render the 1D CrN nanostructure as a compelling candidate for exploiting high-performance spintronic devices.