Tailoring magnetic and electronic properties of NbOCl nanoribbons via edge engineering and chemical passivation

In this study, we unveil the remarkable tunability of electronic and magnetic properties in $\mathrm{NbO}{\mathrm{Cl}}_{2}$ nanoribbons through precise control of edge chemistry, structural reconstruction, and chemical passivation. By investigating nanoribbons oriented along both $x$ and $y$ directions, we reveal how subtle variations in edge termination and symmetry drive emergent phenomena such as edge-localized magnetism, half-metallicity, and unconventional bandgap modulation. Oxygen-rich edges foster spin-polarized flat bands near the Fermi level, enabling potential spin-filtering applications, while niobium-terminated edges exhibit robust metallicity with spin-split states. Structural reconstruction and hydrogen passivation are shown to be powerful tools for stabilizing these low-dimensional systems while selectively tuning their magnetic states either quenching or inducing magnetism depending on the configuration. Notably, wider nanoribbons defy typical quantum confinement trends, with enhanced magnetic interactions leading to unexpected bandgap expansion. These insights demonstrate how $\mathrm{NbO}{\mathrm{Cl}}_{2}$ nanoribbons serve as a versatile platform for engineering next-generation spintronic devices, offering pathways for chemically and structurally driven manipulation of magnetism and electronic transport at the nanoscale.