Evaluation of the energy barrier for failure of Au atomic contact based on temperature dependent current–voltage characteristics
Abstract
We investigated the mechanical stability of single gold atomic contacts at an applied bias voltage of 0–1 V using a nano-fabricated mechanically controllable break junction technique at 300–400 K under ambient conditions. The single atomic contact shows the quantized conductance (G0 = 2e2/h) and can carry considerably large current, which results in the current-induced failure of the contact. The contact failure behaviour under the applied bias conditions was studied by statistical analysis of the current–voltage (I–V) curves of the single Au contacts. We demonstrated that, at the elevated temperature of 300–400 K, the current-induced local heating effect is negligibly small and current-induced forces in the contact are responsible for the observed failure of the single gold contacts under the high bias voltage conditions (>0.4 V). Furthermore, based on the temperature dependence of the contact failure behaviour in the I–V curves, the energy barrier of the contact-failure was evaluated to be ca. 0.1 V.