Observation of excess resistance anomaly at resistive transitions in Ag/Au nanostructures

Abstract

The resistive transition in nanocomposite films of silver (Ag) nanoclusters of ∼ 1 nm diameter embedded in gold (Au) matrix exhibits an anomalous resistance peak at the onset of the transition, even for transition temperatures as high as 260 K. The maximum value of the resistance ranges between ∼ 30% − 300% above that of the normal state depending on devices as well as lead configuration within a single device. The excess resistance regime was observed in about 10 % of the devices, and extends from ∼ 10 − 100 K. Application of magnetic field of 9 T was found to partially suppress the excess resistance. From the critical current behavior, as well as negative differential resistance in the current-voltage characteristics, we discuss the possibility of interacting phase slip centers and alternate physical scenarios that may cause the excess resistance in our system.

Unconventional properties of engineered Au–Ag nanostructures

“…This leads to different work functions and Volta potentials, and therefore the expectation of inhomogeneity in electron density arising from interfacial charge transfer [38,39]. Here we survey the properties of Au-Ag materials as reported in various preprints [40][41][42][43][44]. These include electrical, magnetic, optical and dielectric anomalies.…”

Investigation of the dissipative properties of Au-Ag nanostructures through Electron Energy Loss Spectroscopy

“…Other electrical anomalies were also noted. 11,12 Optically, these nanostructures did not seem to obey Mie theory, since they lack usual Au and Ag like plasmon resonances and exhibit a single broad scattering resonance that covers the ultraviolet-visible spectrum. In a subset of samples, this resonance exhibits an indistinct maximum at ~4 eV.…”