Studies of electric, dielectric, and conduction mechanism by OLPT model of Li4P2O7

Abstract

The polycrystalline samples of Li4P2O7 were prepared by solid-state reaction technique. The formation of the compounds was checked by X-ray diffraction technique (XRD). Detailed dielectric and electrical properties of the compounds were analyzed as a function of frequency (200 Hz–5 MHz) and temperature (611–671 K). The impedance data were well fitted to two equivalent electrical circuits. The results of the modulus study reveal the presence of two distinct relaxation processes suggesting the presence of grains and grain boundaries in the sample. Analysis of the dielectric constants e″ and loss tangent tan (δ) with frequency shows a distribution of relaxation times. The activation energy found from the Arrhenius plot confirms that the conduction process in the material is not due to simple hopping mechanism. The temperature dependence of frequency exponent s was investigated to understand the conduction mechanism in Li4P2O7. The overlapping large polaron tunneling (OLPT) model can explain the temperature dependence of the frequency exponent.