Influence of calcination temperature on structure and dielectric properties of Ca0.8Sm0.4/3TiO3 ceramics prepared via solid-state reaction

This study investigates the effect of calcination and sintering conditions on structure and dielectric properties of Ca0.8Sm0.4/3TiO3 ceramics synthesized via solid-state reaction. The powders calcined at temperatures ranging from 1000 to 1200?C were sintered at temperatures between 1375 and 1500?C for various holding times (1-5 h). X-ray diffraction analyses confirmed single-phase perovskite formation, revealing optimal crystallinity and high phase purity at a calcination temperature of 1100?C and sintering temperature of 1425?C for 4 h. Scanning electron microscopy showed significant grain growth and reduced porosity at higher sintering temperatures and optimal holding times. Energy-dispersive spectroscopy indicated homogeneous elemental distribution. Dielectric measurements demonstrated that optimized sintering conditions enhanced permittivity and quality factors (Qf ~ 14900GHz), as well as improved frequency stability (?f ~ 387 ppm/?C). Furthermore, the composite ceramics formed with Mg0.95Co0.05TiO3 significantly improved dielectric properties and frequency stability, making these materials promising for advanced microwave device applications.