Study of alternative current conduction mechanisms on the -LiFeO 2 - Based solid electrolyte

Abstract

LiFeO₂ layered oxides were synthesized using an enhanced solid-state synthesis technique. Rietveld refinement of the crystal structure revealed that the synthesized materials adopt a cubic system with the Fm-3m space group. The morphological study of our compound was carried out using a scanning electron microscope (SEM). The sample consists of small primary particles on the microscopic scale with a size between 0.20 and 0.75 µm. The vibrational investigation carried out by IR spectroscopy demonstrated the presence of FeO₆ and LiO₆ groups.The semiconductor characteristics of the compound were verified by optical measurement, indicating a bandgap of approximately 2 eV. The dielectric properties of the material were evaluated over a frequency range of 0.1 to 10⁷ Hz at temperatures ranging from 333 K to 523 K.The real part of the dielectric permittivity suggests a high dielectric constant at low frequency and indicates the existence of both space charge and dipolar polarizations.The frequency-dependent conductivity was interpreted according to Jonscher's law. The variation of the power law exponent with temperature suggests that the conduction behavior of the LiFeO₂ compound can be attributed to the large superimposed polaron tunneling (OLPT) model with activation energy Ea = 0.26 eV.