Alloying effects on the 1G0 contact of Au

Abstract Alloying effects on the 1G0 (single-atom) contact of Au has been investigated for four solute elements, Ag, Cu, Pt, and Pd, under bias voltages from 0.2 to 1.0 V. We found that the alloying appreciably affects the formation probability p of the 1G0 contact, but makes little influence on the average 1G0 plateau length 〈τ〉. The latter observation strongly suggests that the 1G0 contact of Au alloys consists of Au atom(s), with no solute atoms participating into the contact. On the other hand, the alloying effect on p was found to be element-dependent. Pd and Pt solutes give rise to a rapid suppression of p with increasing the bias, while the alloying with Cu and Ag yields weak bias dependence of p, which is not much different from that of pure Au.