Effects of Samarium Doping on the Dielectric Properties of BaBi₂Nb₂O₉ Aurivillius Ceramics

This study investigates the influence of samarium (Sm³⁺) doping on the structural, microstructural, mechanical, and dielectric properties of BaBi₂Nb₂O₉ (BBN) ceramics. Using the solid-state reaction method, samples of BaBi_2-xSm_xNb₂O₉ with varying concentrations of Sm (x = 0.01; 0.02; 0.04; 0.06; 0.08; 0.1) were prepared. Thermal analysis, microstructure characterization via SEM and EDS, X-ray diffraction, mechanical testing, and dielectric measurements were conducted. The results revealed that increasing Sm³⁺ concentration led to the formation of single-phase materials with a tetragonal structure at room temperature. Mechanical properties, such as Young’s modulus and stiffness, improved with Sm doping, indicating stronger atomic bonding. Dielectric properties showed that low concentrations of Sm³⁺ slightly increased electrical permittivity, while higher concentrations reduced it. The presence of Sm³⁺ also affected the relaxor properties, evidenced by changes in the freezing temperature and activation energy. Overall, the study concludes that samarium doping enhances the structural and functional properties of BBN ceramics, making them promising candidates for high-temperature piezoelectric and dielectric applications. The findings provide valuable insights into tailoring ceramic materials for advanced technological applications.