Formation of Co Atomic Wire in Hydrogen Atmosphere

We have investigated the conductance and atomic structure of the Co atomic contact in a hydrogen atmosphere. While clean Co did not form an atomic wire, the Co atomic contact could be stretched more than 0.4 nm in a hydrogen atmosphere, indicating the formation of the atomic wire. The interaction between hydrogen and the Co atomic wire was investigated with inelastic tunneling spectroscopy (IETS). The vibrational modes between hydrogen and the Co atomic wire were observed in IETS. The length histogram of the last conductance plateau, the shape of the dI/dV curves, the distribution of the vibrational energy, and previously reported theoretical calculation results suggested the formation of the Co atomic wire in which dissociated hydrogen atoms were adsorbed on the wire.