THERMALLY STIMULATED POLARIZATION-DEPOLARIZATION CURRENT AND POLARIZATION CONDUCTIVITY IN IONICALLY CONDUCTING GLASSES

The polarization conductivity σ'(ω) of Na2O-3SiO2 glass has been studied by impedance spectroscopy (100 Hz-5 MHz). The results are explained on the basis of a free-volume model applied to ionically conducting glasses. The experimental relationship σ'(ω)=AωS was found and the parameter s calculated according to the model. The distribution of relaxation times included in the expression of σ'(ω) was evaluated by thermally stimulated polarization-depolarization current peaks attributed to the bulk polarization. The experimental results related to σ'(ω) and parameter s were compared with the calculations performed by means of a distribution function, determined by the thermally stimulated current technique. There is good agreement between the results showing that the two approaches are complementary. © 1994 The American Physical Society.