Stabilization of monoatomic gold wires by carbon impurities

The influence of atomic and molecular carbon on the structural and electronic properties of a monoatomic gold wire has been studied by means of projector augmented-wave method (PAW) within density functional theory (DFT). Our calculations show that carbon is able to enhance the stability of linear gold chains with large interatomic separations. The Au–Au spacing at breakage can be as long as ∼4.5 and 6 Å for the wires incorporating atomic (Au–C) and molecular carbon (Au–C2), respectively. The calculated band structure for nonmagnetic Au–C reveals the presence of one conduction channel for linear chains, but two channels for zigzag-like ones. A close similarity of this behaviour, to that known for a pure gold wire might indicate little influence of carbon on the conduction properties of gold nanowires.