Synthesis and Complex Dielectric Properties of Ba_0.4Sr_0.6SnO₃ Ceramics with Thorn-like Microstructure

In this study, we synthesized perovskite Ba_0.4Sr_0.6SnO₃ ceramics with a unique thorn-like microstructure using the solid-state reaction method. The structural and complex dielectric properties were investigated in detail. X-ray diffraction was employed to characterize the phase purity, while X-ray photoelectron spectroscopy was used to analyze the chemical state of the components. The frequency and temperature dependence of the dielectric properties indicates that both the dielectric constant and loss are influenced by A-site ion doping as well as the presence of the thorn-like microstructure. The observed dielectric behavior can be explained by the interfacial polarization and dielectric relaxation processes, which arise from the existing Sn⁴⁺-Sn²⁺ pairs, oxygen vacancies, and defects with activation energies of 0.38 eV, 0.73 eV, and 0.54 eV, respectively. The resistances of grain boundaries, grains, and the thorn-like structure were revealed by the impedance spectra. These findings provide valuable insights into understanding structure-property relationships in perovskite stannate ceramics.