Four-probe electrical transport measurements on individual metallic nanowires

Abstract

This work presents nanoscale four-probe measurements on metallic nanowires using independently controlled scanning tunnelling microscope tips. This technique has allowed us to follow the change in resistance with probe separation. Gold, zinc and nickel nanowires were grown by electrodeposition within porous polycarbonate membranes. Their structure and composition were studied by transmission electron microscopy. Four-probe electrical transport measurements were taken using four independently controlled scanning tunnelling microscope tips positioned using a high resolution scanning electron microscope. Multiple I–V measurements were taken at varying tip separations, on each nanowire, and the change in resistance with separation was observed to be in good agreement with predictions based on the nanowire geometry. The resistivity values of the nanowires were found to be close to bulk values.