Hydrogen-assisted stabilization of Ni nanowires in solution

We have studied conductance characteristics of mechanically fabricated Ni nanoconstrictions under controlling electrochemical potential and $pH$ of the electrolyte. The conductance histogram showed a clear feature peaked at 1–1.5 $G0(G0=2e2∕h)$ when the potential of the constriction was kept at more negative potential than $−900mV$ versus $Ag∕AgCl$ at $pH=3.7$⁠. A comparable feature also appeared at a more positive potential when a lower $pH$ solution was used. We have revealed that Ni monoatomic contact or monoatomic wire can be stabilized in solution at room temperature under the hydrogen evolution.