Transport Properties of VOx Multi-Walled Nanotubes

Microwave cavity perturbation technique was used to measure high-frequency (60 GHz) conductivity of VOx multi-walled nanotubes in a wide temperature range of 4.2–80 K. We found that conductivity of VOx nanotubes monotonically increases with temperature. Furthermore, two contributions to high-frequency conductivity can be distinguished: quasi-metallic linear term and thermally activated conductivity with the activation energy EA=150 ± 10 K.