Understanding the structure of the first atomic contact in Gold

Abstract

We have studied experimentally the phenomena of jump-to-contact (JC) and jump-out-of-contact (JOC) in gold electrodes. JC can be observed at the first contact when the two metals approach each other while JOC occurs in the last contact before breaking. When the indentation depth between the electrodes is limited to a certain value of conductance, a highly reproducible behaviour in the evolution of the conductance can be obtained for hundreds of cycles of formation and rupture. Molecular dynamics simulations of this process show how the two metallic electrodes are shaped into tips of a well-defined crystallographic structure formed through a mechanical annealing mechanism. We report a detailed analysis of the atomic configurations obtained before contact and rupture of these stable structures and obtained their conductance using first-principlesquantum transport calculations. These results help us understand the values of conductance obtained experimentally in the JC and JOC phenomena and improve our understanding of atomic-sized contacts and the evolution of their structural characteristics.

Nanoscale Research letters Aceppted 7 pages, 4 figures

References in corpus (5)

• Quantum properties of atomic-sized conductors
• Formation of a Metallic Contact: Jump to Contact Revisited
• Single atom adhesion in optimized gold nanojunctions
• Mechanical annealing of metallic electrodes at the atomic scale
• Highly reproducible low temperature scanning tunnelling microscopy and spectroscopy with in situ prepared tips

Cited by in corpus (6)

• Influence of relativistic effects on the contact formation of transition metals
• The role of first neighbors geometry in the electronic and mechanical properties of atomic contacts
• Modeling contact formation between atomic-sized gold tips via molecular dynamics
• Directional bonding explains high conductance values of atomic contacts in bcc metals
• Dynamic bonding influenced by the proximity of adatoms to one-atom high step edges
• Exploring Three-Atom-Thick Gold Structures as a Benchmark for Atomic-Scale Calibration of Break-Junction Systems