Huixing Lin

Low-Firing and Microwave Dielectric Properties of Ba2Ti9O20 with BaO–B2O3–ZnO Glass Addition

A low-firing ceramic material was fabricated by sintering a mixture of Ba2Ti9O20 with a BaO–B2O3–ZnO (BBZ) glass between 880 and 940 °C for 2 h, and the effects of BBZ glass additives on the sintering behavior and microwave dielectric properties were investigated. The results of this show that as the content of glass increased, the sintering temperature of material decreased. The material can be fully sintered at 900–920 °C with glass additives higher than 15 wt %. Two main crystalline phases, Ba2Ti9O20 and BaTi(BO3)2, were found in the ceramics, and the latter was formed by the reaction between Ba2Ti9O20 and the BBZ glass. The dielectric constant er and the temperature coefficient of resonant frequency τf decreased and quality factor Q×f increased as the content of glass additive increased; ceramics containing 20 wt % BBZ glass additive sintered at 900 °C had er=26.6, Q×f=11952 GHz, τf =-6.6 ppm/°C.

Sintering and Microwave Dielectric Properties of La(Mg0.5Ti0.5)O3 Ceramics Doped with La2O3–B2O3–TiO2 Glass

The effects of La2O3–B2O3–TiO2 (LBT) glass on the microstructures and microwave dielectric properties of La(Mg0.5Ti0.5)O3 ceramics were investigated. With the addition of BLT glass, the densification temperature of La(Mg0.5Ti0.5)O3 can be effectively reduced from 1600 to 1200–1500 °C. It is found that the addition of BLT glass (5–30 wt %) can significantly improve the density and dielectric properties of La(Mg0.5Ti0.5)O3 ceramics. The dielectric properties of La(Mg0.5Ti0.5)O3 ceramics were strongly dependent on the amount of LBT glass added. A er of 25.4, a Q× f value of 13,240 GHz, and a τf of -54.4 ppm/°C were obtained for the 30 wt % LBT glass-doped La(Mg0.5Ti0.5)O3 ceramic sintered at 1200 °C for 3 h.

Investigating the relationship of 1:1 ordering with the quality factor in Sr(Zn1/3Nb2/3)O3 ceramics

Abstract The 1:2 ordering is known to play an important role in quality factor of complex perovskite microwave dielectric ceramics, while the relationship of 1:1 ordering on quality factor is little known. In this work, The 1:1 ordering in Sr(Zn1/3Nb2/3)O3 were studied by X-ray diffraction and Raman spectroscopy. Results show the increased in the quality factor as the sintering time increase is caused mainly by the decrease of the 1:1 ordering degree.

Low-Temperature Sintering and Microwave Dielectric Properties of Ba2Ti9O20 Ceramics with CaO–B2O3–ZnO Glass Additions

The effect of CaO–B2O3–ZnO (CBZ) glass on the microstructures and microwave dielectric properties of Ba2Ti9O20 ceramics was investigated. With the addition of CBZ glass, the densification temperature of Ba2Ti9O20 can be effectively reduced from 1400 to 880–920 °C. It is found that the addition of CBZ glass (20–30 wt %) can significantly improve the density and dielectric properties of Ba2Ti9O20 ceramics. The dielectric properties of Ba2Ti9O20 ceramics were strongly dependent upon the amount of CBZ glass addition. A dielectric constant (er) of 27.0, a quality factor (Q ×f) value of 13,400 GHz, and a temperature coefficient of resonant frequency (τf) of 17.8 ppm/°C were obtained for 20 wt % CBZ glass-doped Ba2Ti9O20 ceramics sintered at 920 °C for 2 h.

The Microwave Characteristics of Glass-Ba2Ti9O20 Ceramics

In this study, 2BaO-3B2O3 (BB) glass was used as a sintering aid to lower the sintering temperature of Ba2Ti9O20 ceramics. Microwave Characteristics of the BB-added Ba2Ti9O20 ceramics sintered at different temperatures were investigated. The crystalline phases of BB-Ba2Ti9O20 ceramics are Ba2Ti9O20, BaTi(BO3)2 and TiO2. Good microwave dielectric properties (εr = 26, Q*f = 28770GHz and τf = 14.6ppm/oC) were obtained by sintering the BB-added Ba2Ti9O20 ceramics at 1040oC for 2 h.