Prediction of Spin-Polarization Characteristics of Al-Doped Single-Walled SiC Nanotubes

Abstract

The present work explores how aluminum substitution affects the electronic, magnetic, and structural properties of single-walled (6,0) silicon carbide nanotubes, based on spin-polarized density functional theory simulations. The incorporation of Al atoms causes pronounced changes in the band structure, driving the system toward half-metallic behavior, where the spin-up channel retains semiconducting characteristics while the spin-down channel exhibits metallic conductivity. Analysis of the partial density of states demonstrates that states close to the Fermi energy primarily originate from the carbon p orbitals together with contributions from aluminum d orbitals. Spin-resolved charge density mapping indicates that a net magnetic moment of nearly 1.0 µ_B is localized mainly on carbon atoms surrounding the dopant. Total energy comparisons between ferromagnetic and antiferromagnetic spin arrangements establish the antiferromagnetic configuration as the ground state. Collectively, these results highlight that Al-doped SiC nanotubes are strong candidates for spintronic applications, particularly in spin filters and antiferromagnetic memory devices, owing to their half-metallicity and robust magnetic ordering.