Study of AC electrical properties of V_2O_5-P_2O_5-B_2O_3-Dy_2O_3 glasses

摘要

The AC conductivity of glass samples of composition 60V_2O_5-5P_2O_5-(35-x)B_2O_3-xDy_2O_3, 0.4 ≤ x ≤1.2 has been analyzed. The samples were prepared by the usual melt-quench technique. The prepared compounds were analyzed by X-ray diffraction (XRD) and thermo gravimetric-differential thermal analysis (TG/DTA). The activation energies were evaluated using glass transition temperature (T_g) and peak temperature of crystallization (T_c) from TG/DTA. The dependence of activation energy on composition was discussed. The electrical conductance and capacitance were measured over a frequency range of 20 Hz to 1 MHz and a temperature range of 303-473 K;;these reveal semiconducting features based predominantly on an ionic mechanism. The dielectric and complex-impedance response of the sample is discussed. The relaxation time was found to increase with increasing temperature. Jonscher's universal power law is applied to discuss the conductivity. The electrode polarization was found to be negligible and confirmed from electrical modulus.