Electrical Conduction and Magnetoresistance of Silver-Stannic Oxide Composite Nanotubes

Abstract

Mesoscopic materials typically have different properties compared to bulk materials because their dimensions can be smaller than certain characteristic lengths. Transport measurements on mesoscopic-sized disordered materials allow us to study quantum corrections to conductivity. In this study, silver-stannic oxide composite nanotubes of different diameters and lengths have been fabricated. Their resistances have been measured from 300 K down to 1.8 K in magnetic fields up to 5 T, applied either parallel or perpendicular to the nanotube axis. At temperatures below 10 K, the resistance has a linear dependence on the natural logarithm of temperature. Applying a range of magnetic fields both parallel and perpendicular to the nanotube axis results in an isotropic and positive magnetoresistance. An analysis of the data rules out weak localization as the dominant conduction mechanism, and it supports the existence of strong electron-electron interactions as the dominant conduction mechanism at low temperatures. Hopping transport mechanisms have also been considered, but they result in unrealistic physical parameters.