Sintering behavior and microwave dielectric properties of TiO2 added Ba4(Sm0.5Nd0.5)28/3Ti18O54 ceramics with K2O–B2O3–SiO2 glass

• Published in: Journal of materials science. Materials in electronics 2016-03, Vol.27 (3), p.2783-2788
• Main Authors: Zhou, Xiaohua, Zhang, Yuqin, Chang, Geng, Yang, Xinshi, Sun, Chengli, Zhang, Shuren
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Materials Science; Optical and Electronic Materials
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-015-4090-0

K 2 O–B 2 O 3 –SiO 2 (KBS) synthesized via a solid-state reaction process was chosen as a novel sintering aid for Ba 6–3x (Sm 1-y , Nd y ) 8+2x Ti 18 O 54  + 2TiO 2 (x = 2/3 and y = 0.5; BSNTT) ceramics. Effects of KBS doping on sintering behavior, microstructure and microwave dielectric properties of BSNTT ceramic were investigated. The appropriate KBS addition significantly lowered the sintering temperature of BSNTT ceramic with slightly damaging its microwave dielectric properties. The X-ray diffraction results showed that all the well sintered samples exhibited the main phase Ba(Sm,Nd) 2 Ti 4 O 12 and a certain amount of Ba 2 Ti 9 O 20 and TiO 2 secondary phases. Besides, the other secondary phase Sm 2 Ti 2 O 7 formed when 9 wt% KBS added. Then the scanning electron microscopy micrographs of the optimally well-sintered (1075 °C for 3 h) ceramics showed a dense microstructure. With the increasing content of KBS addition, both the dielectric constant ( ε r ) and quality factor ( Q  ×  f ) value decreased. At last, the good microwave dielectric properties of ε r  = 68.8, Q  ×  f  = 6766 GHz, τ f  = 28.76 ppm/°C were obtained for BSNTT + 5 wt% KBS ceramic sintered in air at 1075 °C for 3 h.