Observation of large low-frequency resistance fluctuations in metallic nanowires: Implications on its stability

Abstract

We have measured the low frequency $(1\phantom{\rule{0.3em}{0ex}}\mathrm{mHz}\ensuremath{\leqslant}f\ensuremath{\leqslant}10\phantom{\rule{0.3em}{0ex}}\mathrm{Hz})$ resistance fluctuations in metallic nanowires (diameter $15\phantom{\rule{0.3em}{0ex}}\mathrm{nm}\phantom{\rule{0.3em}{0ex}}\text{to}\phantom{\rule{0.3em}{0ex}}200\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$) in the temperature range $77\phantom{\rule{0.3em}{0ex}}\mathrm{K}\phantom{\rule{0.3em}{0ex}}\text{to}\phantom{\rule{0.3em}{0ex}}400\phantom{\rule{0.3em}{0ex}}\mathrm{K}$. The nanowires were grown electrochemically in polycarbonate membranes and the measurements were carried out in arrays of nanowires by retaining them in the membrane. A large fluctuation in excess of conventional $1∕f$ noise which peaks beyond a certain temperature was found. The fluctuations with a significant low frequency component $(\ensuremath{\simeq}1∕{f}^{3∕2})$ arise when the diameter of the wire $\ensuremath{\simeq}15\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$ and vanish rapidly as the diameter is increased. We argue that Rayleigh-Plateau instability is the likely cause of this excess noise.