Ceramics-Silikáty 44 (3) 81-85 (2000)

IONIC AND ELECTRONIC CONDUCTIVITY OF GLASSES IN THE P₂O₅-V₂O₅-Na₂O SYSTEM

M. C. Ungureanu, M. Lévy, J. L. Souquet 

The conductivity of glasses in the y P₂O₅ - (1-y) [(1-x) V₂O₅ - x Na₂O] system is studied as a function of temperature and composition. For all compositions, the conductivity variations as a function of temperature follow an Arrhenius type relationship. The activation energy and pre-exponential factor values determined for the V₂O₅ richest compositions are lower than those obtained for the rich ionic domain. Isothermal variations of the conductivity as a function of composition show deep minima for molar ratios x near 0.65. On either side of these minima, the conductivity is mainly electronic (x < 0.6) or ionic (x > 0.8). The variations are interpreted assuming a prevailing diluting effect of the non predominantly present oxide with no interactions between the electronic and ionic charge carriers.