doi:10.1016/j.jeurceramsoc.2006.11.039
Copyright © 2006 Elsevier Ltd All rights reserved.
Effect of dopants on synthesis of BaTi4O9 and Ba2Ti9O20 ceramics prepared by reaction-sintering process
References and further reading may be available for this article. To view references and further reading you must
purchase this article.
Yi-Cheng Liou
, a,
, Ko-Hao Tsenga and Tzu-Chin Chunga
aDepartment of Electronics Engineering, Kun-Shan University, Tainan Hsien, 71003 Taiwan, ROC
Available online 19 December 2006.
Abstract
The effect of dopants on BaTi4O9 (BT4) and Ba2Ti9O20 (B2T9) ceramics by the reaction-sintering process was investigated. CuO addition is more effective in lowering the sintering temperature of BT4 and B2T9 ceramics. MnO2 and CuO addition are effective to obtain temperature stable BT4 ceramics. With MnO2 addition, Q × f of BT4 ceramics could be raised. ZrO2 addition is effective to obtain B2T9 ceramics with higher dielectric constant. With CuO addition, τf of B2T9 ceramics shifted toward negative values and 0 ppm/°C could be obtained. Optimum properties in BT4 doped with MnO2 of
r = 37.1, Q × f = 51,200 GHz (at 7 GHz) and τf = 0 ppm/°C and in B2T9 doped with ZrO2 of
r = 37.9, Q × f = 39,700 GHz (at 7 GHz) and τf = 5.9 ppm/°C were obtained.
Keywords: Dielectric properties; Reaction-sintering; Titanates
Fig. 1. XRD patterns of BaTi4O9 ceramics doped with 0.1 wt% MnO2 and 0.5 wt% CuO.
Fig. 2. SEM photos of BaTi4O9 ceramics doped with 0.1 wt% MnO2 and sintered at (A) 1150 °C, (B) 1200 °C, (C) 1250 °C and (D) 1300 °C for 4 h.
Fig. 3. Influence of sintering temperature and soak time on the density of BaTi4O9 ceramic doped with 0.1 wt% MnO2 and 0.5 wt% CuO.
Fig. 4.
r and Q × f of BaTi4O9 ceramics doped with 0.1 wt% MnO2 and 0.5 wt% CuO.
Fig. 5. XRD patterns of Ba2Ti9O20 ceramics doped with 0.2 wt% ZrO2 and 0.5 wt% CuO.
Fig. 6. SEM photos of Ba2Ti9O20 ceramics doped with 0.2 wt% ZrO2 and sintered at (A) 1200 °C, (B) 1250 °C, (C) 1300 °C and (D) 1350 °C for 4 h.
Fig. 7. Influence of sintering temperature and soak time on the density of Ba2Ti9O20 ceramic doped with 0.2 wt% ZrO2 and 0.5 wt% CuO.
Fig. 8.
r and Q × f of Ba2Ti9O20 ceramics doped with 0.2 wt% ZrO2 and 0.5 wt% CuO.

Corresponding author. Tel.: +886 6 2050521; fax: +886 6 2050250.