Electronic Transport Properties in α and ɛ Phases of LixV2O5 Bronzes: Radio- and Microwave Frequency Dielectric Studies

We report here conductivity and dielectric studies of chemically synthesized LixV2O5 vanadium bronzes having a lithium content x below 0.55. The measurements were performed on polycrystalline compounds of lithium content x within the frequency range 10 to 1010 Hz at temperatures varying between 300 and 400 K. At low frequencies, i.e. ν < 107 Hz, the complex resistivity or complex conductivity plots allowed us to determine the true dc conductivity of LixV2O5 compounds by taking into account grain boundary and porosity effects. At high frequencies, dielectric relaxation corresponding to polaron hopping has been observed.