Prediction of spin-polarization characteristics of Al@Si -doped single-walled (6,0) SiC nanotubes

In this study, we examine the impact of aluminum substitution on the structural, electronic, and magnetic properties of single-walled (6,0) silicon carbide nanotubes using spin-polarized density functional theory calculations. The introduction of Al into the nanotube lattice significantly alters its electronic structure, leading to a transition toward half-metallic behavior. Specifically, the spin-up channel retains a semiconducting nature, while the spin-down channel becomes metallic, indicating a clear spin-dependent conductivity. The partial density of states analysis reveals that the electronic states near the Fermi level are dominated by carbon p-orbitals, with additional contributions from the d-orbitals of the aluminum dopant. Spin-resolved charge density distributions further show the emergence of a net magnetic moment of approximately 1.0 μB, which is mainly localized on the carbon atoms adjacent to the Al impurity. A comparison of total energies for ferromagnetic and antiferromagnetic configurations indicates that the antiferromagnetic state is energetically more stable and therefore represents the ground state of the system. Taken together, these findings suggest that Al@Si-doped (6,0) SiC nanotubes possess a combination of half-metallic characteristics and stable magnetic ordering, making them promising materials for spintronic applications such as spin filters and antiferromagnetic memory devices.