Self-breaking in planar few-atom Au constrictions for nanometer-spaced electrodes

Abstract

The authors present results on electromigrated Au nanojunctions broken near the conductance quantum of 77.5 S. At room temperature it is found that wires, initially narrowed by an actively-controlled electromigration technique down to a few conductance quanta, continue to narrow after removing the applied voltage. Separate electrodes form as mobile gold atoms continuously reconfigure the constriction. They find, from results obtained on over 300 samples, no evidence for gold cluster formation in junctions broken without an applied voltage, implying that gold clusters may be avoided by using this self-breaking technique.

Real-Time TEM Imaging of the Formation of Crystalline Nanoscale Gaps

“…After a sample has been electromigrated to where the conductance is 5G 0 , the metallic bridge is unstable even with zero applied current. The nanogap then breaks and evolves within seconds to a gap separation of 3-4 nm, which is likely related to earlier ''self-breaking'' reports in nanogap formation [6,9,23].…”

“…There is thus a nonzero divergence in the atomic flux at the sides of the bridge due to the electron wind. As a result, gold is depleted from the ''upstream side'' of the bowtie to form the gap and deposited on the ''downstream side'' to form a hillock [23] [ Fig. 3(f)].…”

Single-molecule transport in three-terminal devices

“…The instability of these gold nanoconstrictions at room temperature-due to mobility and stress in the materialallows spontaneous breaking of the wire, resulting in two separate electrodes [64,65]. On a timescale of tens of minutes or hours the wires break until they reach conductance values 100 μS without any applied bias.…”

Manipulation of organic polyradicals in a single-molecule transistor

“…[18][19][20] The current, I , was measured as a function of source drain voltage V and gate voltage V g at a temperature T = 2 K. The differential conductance dI/dV was obtained from pointwise linear fits of the I (V ) data.…”