Metal atomic contacts under defined environmental conditions

Abstract

We have developed a measurement system for investigating metal atomic contacts under defined environmental conditions (0.1 Pa-10 5 Pa, 4 K-300 K). Using this newly developed system, the conductance behavior and lifetime of Au atomic contacts were investigated in vacuum and in an oxygen atmosphere (~10 5 Pa) at room temperature. The conductance curves and conductance histograms of the Au contacts in vacuum agreed with those measured in the oxygen atmosphere, indicating a weak interaction between oxygen and Au atomic contact. While the conductance behavior was not affected by the presence of oxygen, the lifetime of the Au atomic contact was slightly increased by the presence of oxygen.

Highly stable Au atomic contacts covered with benzenedithiol under ambient conditions

“…In our previous study, we revealed that the lifetime of the Au atomic contacts in a gas like O 2 was about four times larger than that in vacuum. 21 The lifetime of the Au atomic contact increases by four times in air, and it increases further by 10 times by chemical modification with BDT, meaning the lifetime of the Au atomic contacts for BDT/Au contacts is about 40 times larger than that for clean Au contacts.…”

“…CO, O 2 ) could adsorb on Au atomic contacts. The molecular adsorption on Au atomic contact stabilizes it, [7][8][9][10][21][22][23] leading to appearance of the longer lifetime tail in distribution (Fig. 3(a)).…”