Dielectric and AC Conductivity Analysis of LS-2 Ceramics for Thermally Stable Applications

This work presents a focused investigation of the dielectric and electrical conduction properties of LS-2 ceramics, synthesized from Li2CO3 and SiO2 in a 1:2 molar ratio. Building on earlier comparative studies, the present study examines LS-2 in isolation to highlight its potential as a thermally stable, low-loss dielectric material. Dielectric constant, loss tangent, and AC conductivity were measured over a wide temperature (35o-400oC) and frequency (100 Hz-5 MHz) range. The dielectric constant exhibits a thermally stable response, while dielectric loss decreases with frequency, indicating reduced energy dissipation suitable for high-frequency applications. AC conductivity follows Jonscher’s power law and exhibits thermally activated behaviour with a negative temperature coefficient of resistance.Arrhenius analysis reveals two conduction regimes with activation energies of 0.048-0.058 eV (low temperature) and 0.13-0.36 eV (high temperature), indicating hopping conduction mediated by mobile Li+ ions and oxygen vacancies. Field emission scanning electron microscopic analysis reveals a relatively dense and heterogeneous microstructure, consistent with the multiphase nature confirmed by X-ray diffraction, which contributes to interfacial polarization effects.These results demonstrate that LS-2 ceramics exhibits stable dielectric behaviour and is a promising candidate for high-frequency dielectric applications. The study also provides a basis for further optimization through microstructural control and dopant incorporation.