Investigation of Dielectric Behavior, Diffuse Phase Transition, and Optical Band Gap in Polycrystalline KSr0.5Fe2O4 Ceramics

This study investigates the dielectric phase transition and optical properties of polycrystalline KSFO (KSr0.5Fe2O4). The temperature dependence of the dielectric constant reveals clear phase-transition behavior. Diffuse phase characteristics are evaluated using the modified Curie–Weiss law and Lorentzian analysis. Dielectric analysis as a function of temperature indicates a ferroelectric–paraelectric (FE–PE) transition, evidenced by a pronounced increase in the real part of the permittivity near 480 K. At lower temperatures, the material exhibits high dielectric permittivity and low dielectric loss, highlighting its potential for energy storage applications. Optical measurements yield a direct band gap of 2.10 eV, confirming the semiconducting nature of the KSFO ceramic. Overall, these results suggest that KSFO is a promising candidate for multifunctional device applications.