Granular Effect on Electron Conduction in Discontinuous Metal Films

Abstract

The seminal work by Dolan and Osheroff [Phys. Rev. Lett. 43, 721 (1979)], which reported anomalous low‐temperature conduction of high‐resistivity thin‐film metal strips is reanalyzed. It is argued that the observed logarithmic increase of resistance with decreasing temperature in their 3 nm thick Au–Pd strips can be ascribed to the granularity effect on electron conduction in discontinuous metal films. This reanalysis is further supported by the measurements on conducting Pb x (SiO2)1−x nanogranular films, where x is the volume fraction of Pb.