ELECTRONIC-PROPERTIES OF NA0.33V2O5 BRONZE OBTAINED BY THE SOL-GEL PROCESS

Studies on magnetic susceptibility, electron paramagnetic resonance, electrical conductivity, and dielectric relaxation measurements of β-Na0.33V2O5 bronze powders and films obtained by the sol-gel process are presented. According to magnetic susceptibility measurements, the V4+ ions occupy 56% of the V1 sites and 11% of the V3 sites and it is shown by EPR studies that the bipolaron model describes the electronic properties of the bronze as in the case of the bronze obtained by solid state reaction. Electrical conductivity and dielectric relaxation measurements have also shown that this method of preparation does not affect the electronic transport properties, which can be interpreted in terms of a collective motion of bipolarons with a correlation time of 10-11 sec. © 1991.