Characterization of the structure and conduction behavior of overlapping polaron tunnel of dipotassium zinc orthogermanate.

• The K 2 ZnGeO 4 compound was prepared by the conventional high temperature solid-state reaction. • Electrical properties of the compound have been studied using complex impedance spectroscopy. • The frequency dependence of the conductivity is interpreted using Jonscher relation. • The overlapping large polaron tunneling (OLPT) model was a closely model to describe the conduction mechanism. In this work, we are focused to study the structural, vibrational and electrical properties of K 2 ZnGeO 4 ceramic compound. The KZGO was prepared by conventional solid-state method. X-ray diffraction (XRD) analysis reveals that the sample is well crystallized in the orthorhombic structure with Pca2 1 space group. Moreover, IR spectrum for this compound confirm the presence of group functionally [GeO4]4-. The electrical measurements was studied in the 40 Hz–1 MHz frequency interval and 533–653 K temperature range. AC conductivity of K 2 ZnGeO 4 is showed on the basis of the overlapping large polaron tunneling (OLPT) model. The activation energy calculated from both the DC conductivity and modulus spectra are close quite to notify that the electrical conductivity and the relaxation process are attributed to the same effect. Thermodynamic parameters for instance the enthalpy ΔH, and the change in entropy ΔS and the free energy of activation ΔF have been determined. [ABSTRACT FROM AUTHOR]