Complex Impedance Study in Bi₂O₃--WO₃

抄録

The complex impedance in (Bi₂O₃)_1-x(WO₃)_x (x=0.23 and x=0.25) in the δ ^* phase has been measured over the temperature range 300, K to 740, K and the frequency range 500, Hz to 20, MHz. The electrical conduction is found to be due to the thermally activated motion of oxygen ions. The frequency dependence of the impedance shows the characteristic features of the universal dielectric response and is described by an empirical Jonscher type relaxation function. The activation energy is estimated for the hopping motion of the oxygen ions. The diffusive motion of the mobile ions is discussed on the basis of the cage-effect jump-relaxation model.