Spontaneous magnetization of aluminum nanowires deposited on the NaCl(100) surface

We investigate electronic structures of Al quantum wires, both unsupported and supported on the (100) NaCl surface, using the density-functional theory. We confirm that unsupported nanowires, constrained to be linear, show magnetization when elongated beyond the equilibrium length. Allowing ions to relax, the wires deform to zigzag structures with lower magnetization but no dimerization occurs. When an Al wire is deposited on the NaCl surface, a zigzag geometry emerges again. The magnetization changes moderately from that for the corresponding unsupported wire. We analyze the findings using electron band structures and simple model wires.