Phase development and microwave dielectric properties of BaO-xSm₂O₃-4.5TiO₂ (x = 0-1.25) ceramics

In order to trace the reaction sequence during conventional solid-state reaction in BaO-xSm₂O₃-4.5TiO₂ (0.0≤x≤1.25) system, of which the phase development process is not clearly known, different barium sources of BaCO₃ and BaTiO₃ were used as starting materials. From the analysis of X-ray powder diffraction (XRD) patterns, different secondary phases could be identified depending on the barium source used, which might mean that the equilibrium phases in BaO-xSm₂O₃-4.5TiO₂ system are very difficult to be synthesized. When BaTiO₃ was used as a raw material, because the precursor provides short diffusion paths of ions, the system revealed less secondary phases that was considered to be closer to the equilibrium state. The microwave dielectric properties of the sample used BaTiO₃ showed superiority accordingly. Microstructure and dielectric properties were examined and discussed in terms of secondary phase development.