One-by-One Introduction of Single Lattice Planes in a Bottlenecked Gold Contact during Stretching

Abstract

We observed the structural and conductance evolution of bottleneck-shaped gold contacts with [111] and [100] axes ([111] and [100] contacts) simultaneously during stretching. The [111] and [100] contacts were elastically stretched until a single (111) or (100) lattice plane was introduced by plastic deformation. The conductance decreased gradually by about 0.5 -0:8G 0 in the elastic regime, and subsequently stepped down at the plastic deformation. Since the conductance values changed depending on the strain, they were not quantized. The conductance histograms displayed rather broad peaks due to the elastic regime. These peaks reflected the particular sequence of the mechanical deformation of the contacts, in strong contrast to the peaks of the [110] contacts, which reflected the quantization as reported previously. Below 10G 0 , we found that the gold [111] and [100] contacts had five and three specific structures, respectively, in addition to a single-atom contact at 1G 0 . We conclude that, for a bottlenecked gold contact, the strain extends over many lattice fringes along the stretching axis and the yield do not occur until sufficient space is available to introduce an additional atomic layer.

In situTEM observation of controlled gold contact failure under electric bias

“…During the thinning process, the Au contact became a bottlenecked shape which was suspended between two electrodes surrounded by three {111} and/or {100} facets as reported previously. 18 These observations are the same as mentioned by Strachan et al 8 ("unzipping model"). Also, we observed that both electrodes were asymmetric in shape at the failure, as shown by Heercshe et al 7 But, we found that very thin Au contacts fractured in a controlled manner even under electric bias, although they were reported to be broken spontaneously under no electric bias in the previous works.…”

Peculiar Atomic Bond Nature in Platinum Monatomic Chains

“…Figure b,c presents the typical time evolution of the conductance and stiffness of a Pt nanocontact, respectively; while Figure d shows a series of TEM images acquired during stretching, which was controlled by the tube piezo at a rate of 0.08 nm/sec. The conductance showed distinct plateaus and stepwise changes over time, corresponding to the elastic and plastic deformation of the Pt nanocontact, respectively (Figure b) . Similarly, the stiffness exhibited stepwise change that was associated with the initiation of plastic deformation (Figure c).…”

The increase in conductance of a gold single atom chain during elastic elongation

“…Gold SACs also have great potential in applied fields such as nanoelectronics. Many experimental [1][2][3][4][5][6][7][8][9][10] and theoretical [11][12][13][14][15][16][17][18][19][20][21][22][23][24] studies have been carried out to explain the SAC formation and its electrical characteristics. Using density-functional theory (DFT) simulations, it was found that during the nanowire elongation, the arrangement of the gold atoms changes from three-dimensional (3D) phases to a variety of two-dimensional (2D) phases and finally to SACs, which elongate gradually from one up to about nine atoms in the chain.…”