TY - JOUR
T1 - Low firable BiNbO4 based microwave dielectric ceramics
AU - Huang, Cheng Liang
AU - Weng, Min Hang
AU - Yu, Cheng Chi
N1 - Funding Information:
This work was co-supported by the National Science Council of the Republic of China under grant NSC-89-2213-E-006-085 and the Foundation of Jieh-Chen Chen Scholarship, Tainan, Taiwan, Republic of China.
PY - 2001
Y1 - 2001
N2 - The sintering behavior, the microstructures and the microwave dielectric properties of Bi(Nb, Ta)O4 ceramics with different amount of CuO additions were investigated. The CuO additive, appeared at grain boundary and acted as a sintering aid, could effectively lower the sintering temperature of BiNbO4 ceramics. However, too many CuO additions (> 1 wt.%), too long a soaking time (> 3 h) or too high a sintering temperature (> 960°C) would cause abnormal grain growth resulted in the degradation of densities and dielectric properties of BiNbO4 ceramics. To investigate the microstructures and the dielectric properties of Bi(Nb, Ta)O4 ceramics, 0.5 wt.% CuO addition was selected as a proper sintering aid to reduce the sintering temperature. The dielectric constant εr of BiNb(1-x)TaxO4 ceramics was not significantly changed with Ta substitution and saturated at 44-45 for dense ceramics. The obtained quality values (Q × f) ranged from 4000 to 21 000 (GHz) were found to be functions of the sintering temperatures and the amount of Ta substitution. The τf values were shifted toward negative direction and became more negative with the increase of Ta content. Zero temperature coefficient of resonator frequency could be obtained by properly adjusting the Ta content.
AB - The sintering behavior, the microstructures and the microwave dielectric properties of Bi(Nb, Ta)O4 ceramics with different amount of CuO additions were investigated. The CuO additive, appeared at grain boundary and acted as a sintering aid, could effectively lower the sintering temperature of BiNbO4 ceramics. However, too many CuO additions (> 1 wt.%), too long a soaking time (> 3 h) or too high a sintering temperature (> 960°C) would cause abnormal grain growth resulted in the degradation of densities and dielectric properties of BiNbO4 ceramics. To investigate the microstructures and the dielectric properties of Bi(Nb, Ta)O4 ceramics, 0.5 wt.% CuO addition was selected as a proper sintering aid to reduce the sintering temperature. The dielectric constant εr of BiNb(1-x)TaxO4 ceramics was not significantly changed with Ta substitution and saturated at 44-45 for dense ceramics. The obtained quality values (Q × f) ranged from 4000 to 21 000 (GHz) were found to be functions of the sintering temperatures and the amount of Ta substitution. The τf values were shifted toward negative direction and became more negative with the increase of Ta content. Zero temperature coefficient of resonator frequency could be obtained by properly adjusting the Ta content.
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U2 - 10.1016/S0272-8842(00)00086-9
DO - 10.1016/S0272-8842(00)00086-9
M3 - Article
AN - SCOPUS:0035063896
SN - 0272-8842
VL - 27
SP - 343
EP - 350
JO - Ceramics International
JF - Ceramics International
IS - 3
ER -