Study on structural and conduction behavior of overlapping polaron tunnel of SrZnP2O7

Abstract

The pyrophosphate compound family has garnered considerable attention recently due to their versatile properties. In this research, our focus was to investigate the structural, morphological, and electrical characteristics of the ceramic compound SrZnP₂O₇ which is elaborated via the solid-state process. X-ray diffraction reveals that the compound has a well-defined crystalline structure in the monoclinic phase having a P121/n1 space group. Scanning electronic microscope and energy dispersive spectroscopy reveals the purity of structure with particle size around 490 nm. The study of complex impedance spectra shows that the electrical properties of SrZnP₂O₇ sample are heavily dependent on frequency and temperature, indicating a relaxation phenomenon and semiconductor-type behavior. The frequency-dependent "ac" conductivity, evaluated using Jonscher's law, was built to be temperature-dependent. The curves of imaginary parts of impedance (Z″) and modulus (M″) show dielectric-relaxation phenomenon in the sample with activation energy near to that determined from the dc conductivity study. The conduction mechanism is conclusively governed by the overlapping large polaron tunneling model. Additionally, accurate computation of thermodynamic parameters such as enthalpy change (ΔH), entropy change (ΔS), and free energy of activation (ΔF) contributes further insights into the compound's properties. The findings demonstrate that SrZnP₂O₇ holds significant potential for various technological applications, including low-temperature co-fired ceramics, microwave technologies, and fuel cells.