Tailoring dielectric and electrical properties of Gd doped BaTiO3 ceramics for energy device applications

This study reports the thermal, dielectric, and electrical transport behavior of ceramics synthesized through a conventional solid state reaction route. The incorporation of trivalent Gd 3+ ions into the single-phase tetragonal perovskite BaTiO 3 stricture induces microstrain and alteration in lattice parameters. Dielectric measurements analysis confirms localized relaxation phenomena, and further determine that moderate Gd substitution enhances the functional properties. The sample with has the highest real dielectric constant (165 at 134 °C and 1 kHz) and a substantial reduction in dielectric loss, confirming improved dielectric efficiency. Impedance spectroscopy reveals a decrease in grain boundary resistance and confirms thermally activated conduction, while ac conductivity follows Jonscher’s universal power law, indicating defect-mediated hopping. The activation energy derived from dc conductivity decreases from 0.72 eV to a minimum of 0.43 eV, suggesting enhanced carrier mobility due to oxygen vacancy assisted transport. The frequency exponent 's' shows a decreasing trend with temperature, validating the correlated barrier hopping model. Thus, from the results it is found that the Gd 3+ doping at optimal concentration effectively tailors the dielectric and electrical behavior of BaTiO 3 ceramics. The composition determines an optimal balance of higher permittivity, lower dielectric loss, and stable conduction, making it a promising lead-free candidate for energy storage capacitors, multilayer ceramic capacitors, and electrothermal devices.