Dielectric relaxation and ionic conductivity studies of Ag₂ZnP₂O₇

Abstract

The complex impedance of the Ag₂ZnP₂O₇ compound has been investigated in the temperature range 419–557 K and in the frequency range 200 Hz–5 MHz. The Z′ and Z′ versus frequency plots are well fitted to an equivalent circuit model. Dielectric data were analyzed using complex electrical modulus M* for the sample at various temperatures. The modulus plot can be characterized by full width at half-height or in terms of a non-exponential decay function $\phi \left( {\text{t}} \right) = \exp {\left( { - {\text{t}}/\tau } \right)^\beta }$. The frequency dependence of the conductivity is interpreted in terms of Jonscher’s law: $\sigma \left( \omega \right) = {\sigma_{\text{dc}}} + {\text{A}}{\omega^n}$. The conductivity σ _dc follows the Arrhenius relation. The near value of activation energies obtained from the analysis of M″, conductivity data, and equivalent circuit confirms that the transport is through ion hopping mechanism dominated by the motion of the Ag⁺ ions in the structure of the investigated material.