Fabrication of stable metal nanowire showing conductance quantization in solution

We have mechanically fabricated Cu nanowires in solutions with and without thiourea. In both solutions, the conductance was quantized in units of G0 (2e2/h). A well-defined 1 G0 peak was observed in the conductance histogram. While the conductance value was not changed, the stability of the mono atomic contact was improved by adding thiourea. The effect of thiourea on the stability of the atomic contact was investigated by measuring the stretched length of the atomic contact. The average length of the last plateau was 0.044 nm in the solution without thiourea. The length increased to 0.076 nm in the solution with thiourea. The stabilization could be explained by the decrease in the surface energy caused by adsorption of thiourea molecules on the Cu nanowires.