Sintering behaviour, phase composition, microstructure, and dielectric properties of BaSm2O4 microwave ceramics

摘要

? 2022 Elsevier Ltd and Techna Group S.r.l.BaSm2O4 was prepared by the conventional solid-phase reaction method. Single-phase dense BaSm2O4 ceramic (space group: Pnam) was obtained at 1500 °C. Crystal refinement results show that BaSm2O4 ceramics have a CaFe2O4 structure. The change of Q × f is explained by calculating the stack fraction and radial shrinkage of BaSm2O4 ceramics. When the sintering temperature was 1500 °C, the packing fraction and radial shrinkage of the BaSm2O4 ceramic reached the maximum values of 52.194% and 36%. Due to secondary recrystallization, the relative density of the ceramics increases and then decreases, reaching a maximum of 1500 °C (96.65%). In addition, the τ? value is affected by SmO6 octahedral distortion. The ceramics have the best combined dielectric properties after sintering at 1500 °C for 4 h: εr = 10.99, Q × f = 54598 GHz, τ? = ?25.4 ppm/°C. BaSm2O4 ceramics have good prospects for applications in the field of mobile communication base stations.