Break Voltage of the 1G₀ Contact of Noble Metals and Alloys

Abstract

We have measured the break voltage of the 1G₀ contact of Au, Ag, Cu, and AuAg alloys at room temperature in ultrahigh vacuum. Exploiting the break junction technique, we produced a 1G₀ contact and broke it by applying a voltage ramp. The break voltage of each metal exhibits a broad distribution, and the average break voltage decreases as Au >Cu ≥ Ag, in consistent with the elemental dependence of the high-bias stability of the 1G₀ contact suggested in previous experimental studies. In AuAg alloys, the break-voltage distribution for some alloys exhibits a double-peak structure, each peak locating close to the break voltage of the 1G₀ contact of pure Au and Ag, respectively. This observation suggests that the break voltage of AuAg alloys is locally determined by the elemental species of the atom occupying the contact site. [DOI: 10.1380/ejssnt.2009.891]