Effects of ZnO-B₂O₃-SiO₂ addition on the microwave dielectric properties of Ba(Nd_1-xBi_x) ₂Ti₄O₁₂ ceramics

ZnO- B₂O₃ -SiO₂ glass effects on both the sintering behavior and microwave dielectric properties of BaO. (Nd _1-xBi_x)₂O₃. 4TiO₂ (BNBT) ceramics were investigated in developing low-temperature-fired dielectric ceramics for microwave devices. Glass wetting characteristics on the BNBT surface, X-ray diffractometer (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and a dilatometer were used to examine the ZnO-B₂O₃-SiO₂ glass effect on BNBT densification and the chemical reaction between the glass and BNBT. The results indicate that ZnO-B₂O₃-SiO₂ glass can be used as a sintering aid to reduce the densification temperature of BNBT from 1300°C to 900°C. The substitution of Bi for Nd in BNBT affected the densification behavior, microstructure, and dielectric properties. BNBT ceramics with 8wt% ZnO- B₂O₃ -SiO₂ glass sintered at 900°C show a relative density of 98%, a high dielectric constant of 61.2, a quality factor (Qf) of 7924, and a temperature coefficient of resonant frequency of 9ppm/°C.