The investigation of dielectric properties and ac conductivity of new ceramic diphosphate Ag0.6Na0.4FeP2O7 using impedance spectroscopy method

• The new compound Ag0.6Na0.4FeP2O7 has been synthesized by solid state reaction method and characterized by X-ray diffraction (XRD), SEM, vibrational spectroscopy and impedance measurements.
• Analysis of the conductivity data and the frequency exponent s shows that the correlated barrier hopping of polaron is the most favorable mechanism for ac conduction throughout the temperature range under consideration.
• Structural factors in this diphosphate are of importance for ionic mobility, such as size of the bottleneck through which Na+ and Ag+ ions diffuse.

In this paper, Ag0.6Na0.4FeP2O7 has been synthesized by solid state reaction method. The ceramic compound was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), vibrational spectroscopy and impedance measurements. In fact, the investigated sample has shown single phase type monoclinic structure with P21/C space group. The frequency-dependent electrical data are analyzed in the frame-work of conductivity and electric modulus formalisms. The real and imaginary parts of complex impedance are well fitted to equivalent circuit model based on the Z-View-software. Besides, the observed frequency dependence of conductivity is found to obey Jonscher's universal law. The temperature dependence of both ac conductivity and the parameter s is reasonably well interpreted by the correlated barrier hopping (CBH). The theoretical fitting between the proposed model and the experimental data showed good agreement. The contribution of single polaron and bipolaron hopping to a.c. conductivity in present compound is also studied. The ionic conductivity is discussed on the basis of the structural characteristics of the sample.