Conductivity Features Of Semiconducting Tungsten-Phosphate Glasses

The ac conductivity of 70WO(3)-30P(2)O(5) glass composition prepared by melt quenching was first studied in the temperature range 25 degrees C to 350 degrees C. The conductivity of the semiconducting glass is investigated with various electrodes (Pt and Ga-Ag alloy). It is shown that the type of spectrum of cell impedance depends on the chosen electrodes. The influence of the samples geometry on the conduction is established. The influence of gas atmosphere (argon, oxygen, and air of different humidity) on electrical conductivity of tungsten-phosphate glass on is studied for the first time. A mixed electronic-ionic conductivity in the 70WO(3)-30P(2)O(5) glass is found out. The transport numbers are shown as a function of temperature. Ionic and electronic contribution to the conduction is estimated. The electrical conductivity of glass undergoes changes from 8.6 x 10(-8) (25 degrees C) to 3.1 x 10(-4) S/cm (300 degrees C) in air.