Transport and optical conductivity in NaxWO3
Laboratorium für Festkörperphysik ETH-Zürich, 8093 Zürich, Switzerland
2 Institut Josef Stefan, 1001 Ljubljana, Slovenia
Published online: 15 July 2000
We present the results of a dc transport and optical investigation of WO3 and NaxWO3 with x=0.01. Upon Na-doping we find a (Drude) metallic component in the optical conductivity, while the transport data display a crossover from an activated to a variable range hopping regime around 210 K. We suggest the possible formation of polarons (and bipolarons) and speculate that superconductivity could be induced, provided the dc percolation threshold is achieved.
PACS: 78.20.-e – Optical properties of bulk materials and thin films / 74.25.Fy – Transport properties (electric and thermal conductivity, thermoelectric effects, etc.)
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2000