Magnetic coupling properties of Mn-doped AlN nanowires: First-principles calculations

► Bulk-like sites in AlN nanowires are the stable doped positions for Mn atoms. ► Surface-passivated Mn-doped AlN nanowires display ferromagnetic properties. ► Unpassivated Mn-doped AlN nanowires display anti-ferromagnetic properties. ► Holes strongly affect the stability of ferromagnetism in Mn-doped AlN nanowires.