Conduction in cosputtered Au-SiO2films

The percolation behavior and the temperature dependence of the resistivity of cosputtered Au-SiO2 films has been studied in films ranging in thickness from 10 to 1000 nm. We find evidence for dimensional crossover effects. At low temperatures, weak-localization behavior with positive magnetoresistance is observed in samples on the metallic side of the percolation transition. On the insulator side of the transition and very close to it, the temperature dependence of the resistivity shows a crossover from exp(1/T1/4)- to exp(1/T1/2)-type behavior, suggesting that more than one conduction mechanism occurs.