Effect of Sintering Temperature on CuO Doped Barium Zinc Tantalate (BZT) Dielectric Properties

2016 ◽  
Vol 840 ◽  
pp. 8-13
Author(s):  
Hidayani Jaafar ◽  
Zainal Arifin Ahmad ◽  
Mohd Fadzil Ain

The structure and dielectric properties of Barium Zinc Tantalate (BZT) doped by copper oxide (CuO) with a variety of values of mol% doping from 0, 0.1, 0.25, 1.0, 1.5 and 2.5 were prepared using a solid state method. The addition of CuO did not disturb the 1:2 ordering structure of the BZT ceramic. The grain size increased when the addition of doping increased. A small amount of doping elements increased the relative density. The dielectric constant (ɛr) value of the BZT significantly improved with the addition of the CuO for the specimens sintered at 1250°C and it could be explained by the increase of the relative density. The tan δ of the CuO doped with BZT ceramics is lower than pure BZT ceramics, and decreases as the CuO content increases. Meanwhile, for the percentage of bandwidth (%BW) it is shown that the best result is produced when it is doped with 0.25 mol% CuO and sintered at 1250°C. The best microwave dielectric properties obtained were ɛr=70.28, tan δ = 0.024, %BW = 7.83 which occurred for the 0.25 mol% doped CuO and when sintered at 1250°C/4 h.

2013 ◽  
Vol 845 ◽  
pp. 446-450
Author(s):  
Hidayani Jaafar

The effect of CaO on microstructure and dielectric properties of Ba (Zn1/3Ta2/3)O3(BZT) ceramics was investigated. The addition of CaO disturbed the 1:2 ordering to 1:1 ordering structure of BZT ceramic. The average grain size significantly increased with the addition of CaO and formed a more compacted structure. The relative density increased with the addition of a small amount of CaO, but it decreased when the CaO content was increased. The dielectric constant (ɛr) value of the BZT significantly improved with the addition of the CaO for the specimens sintered at 1250°C and it could be explained by the increased of the relative density. However, for the specimens sintered at 1300°C, the dielectric constant value decreased with the addition of CaO which is attributed to the decrease of the relative density. The tan δ of the CaO doped with BZT ceramics is lower than pure BZT ceramics, and decreases as the CaO content increases. Meanwhile, for the percentage of bandwidth (%BW) it is shown that the best result is when it is doped with 0.5 mol% CaO and sintered at 1250°C. The best microwave dielectric properties obtained are ɛr=70.44, tan δ = 0.025 which occur for the 0.5 mol% doped CaO and when sintered at 1250°C/4 h.


2008 ◽  
Vol 368-372 ◽  
pp. 179-182
Author(s):  
Zong Chi Liu ◽  
Dong Xiang Zhou ◽  
Shu Ping Gong

The effects of CuO-MoO3 addition on the sintering behavior and microwave dielectric properties of ZnO-TiO2 ceramics were investigated. ZnO-TiO2 ceramics were prepared with conventional solid-state method and sintered at temperatures from 850 to 1050 °C. The sintering temperature of ZnO-TiO2 ceramics with CuO-MoO3 addition could be effectively reduced to 950 °C due to the liquid phase effects resulting from the additives. A proper amount of CuO-MoO3 addition could effectively improve the densification and microwave dielectric properties of ZnO-TiO2 ceramics. ZnO-TiO2 ceramics with 3 wt% addition sintered at 950 °C for 4 h exhibited better microwave dielectric properties as follows: εr of 26.8, a Q×f value of 16780 GHz at 5.42 GHz, and a τ f value of +34.7 ppm/°C.


2010 ◽  
Vol 434-435 ◽  
pp. 224-227
Author(s):  
Xu Ping Lin ◽  
Jing Tao Ma ◽  
Bao Qing Zhang ◽  
Ji Zhou

The influence of CuO-V2O5-Bi2O3 addition on the sintering behavior, phase composition, microstructure and microwave dielectric properties of Zn3Nb2O8 ceramics were investigated. The co- doping of CuO, V2O5 and Bi2O3 can significantly lower the sintering temperature of Zn3Nb2O8 ceramics from 1150°C to 900°C. The Zn3Nb2O8-0.5wt% CuO-0.5wt% V2O5-2.0wt% Bi2O3 ceramic sintered at 900°C showed a relative density of 97.1%, a dielectric constant (εr) of 18.2, and a quality factor (Q×f) of 36781 GHz. The dielectric properties in this system exhibited a significant dependence on the relative density, content of additives and sintering temperature. The relative density and dielectric constant (εr) of Zn3Nb2O8 ceramics increased with increasing CuO-V2O5-Bi2O3 additions. And also the relative density and dielectric constant of Zn3Nb2O8 ceramics increased by the augment of the sintering temperature.


1998 ◽  
Vol 13 (10) ◽  
pp. 2945-2949 ◽  
Author(s):  
Whan Choi ◽  
Kyung-Yong Kim ◽  
Myung-Rip Moon ◽  
Kyoo-Sik Bae

Effects of Nd substitution with Bi on the microwave dielectric properties of BiNbO4 were studied. Bi1−xNdxNbO4 ceramics sintered at 920–980 °C consisted of orthorhombic and triclinic phases. The amount of triclinic phase increased with the increase in the Nd content, x, and sintering temperature. The apparent density and the dielectric constant decreased with the Nd content, but increased with sintering temperature, reached the peak values at 960 °C and then rapidly decreased. The Q × f0 value was between 11,000 and 13,000 GHz over all sintering temperatures for x < 0.05, but for x ≥ 0.05 it reached the peak value at 950 °C and then rapidly decreased. The temperature coefficient of resonance frequency increased in the positive direction with the Nd content and showed the minimum value of −1.82 ppm/°C for x = 0.025 sintered at 940 °C. However, it rapidly increased in the negative direction for sintering temperature over 960 °C.


2007 ◽  
Vol 336-338 ◽  
pp. 279-282
Author(s):  
In Sun Cho ◽  
Sang Gu Kang ◽  
Dong Wan Kim ◽  
Kug Sun Hong

The effects of CuO and V2O5 addition on sintering behaviors and microwave dielectric properties of 0.7Ca2P2O7-0.3TiO2 ceramics were investigated. With CuO and V2O5 addition, the sintering temperature of 0.7Ca2P2O7-0.3TiO2 can be effectively reduced from 1150 to 950oC. The dielectric constant of the low fired 0.7Ca2P2O7-0.3TiO2 ceramics was not significantly changed while the quality factor was affected by additives. The temperature coefficient of resonant frequency value was increased in negative value with the additive contents. V2O5 and CuO additives effectively improved the densification and dielectric properties of 0.7Ca2P2O7-0.3TiO2 ceramics. The correlation between the phase constituents and the dielectric properties was investigated with additive contents.


Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4187 ◽  
Author(s):  
Min-Hang Weng ◽  
Chihng-Tsung Liauh ◽  
Shueei-Muh Lin ◽  
Hung-Hsiang Wang ◽  
Ru-Yuan Yang

The effect of CuO/B2O3 additions on the sintering behaviors, microstructures, and microwave dielectric properties of 0.95LaAlO3–0.05CaTiO3 ceramics is investigated. It is found that the sintering temperatures are lowered efficiently from 1600 °C to 1350 °C, as 1 wt % CuO, 1 wt % B2O3, and 0.5 wt % CuO +0.5 wt % B2O3 are used as the sintering aids due to the appearance of the liquid phase sintering. The microwave dielectric properties of 0.95LaAlO3–0.05CaTiO3 ceramics with the sintering aid additions are strongly related to the densification and the microstructure of the sintered ceramics. At the sintering temperature of 1300 °C, the 0.95LaAlO3–0.05CaTiO3 ceramic with 0.5 wt % CuO + 0.5 wt % B2O3 addition shows the best dielectric properties, including a dielectric constant (εr) of 21, approximate quality factor (Q × f) of 22,500 GHz, and a temperature coefficient of the resonant frequency (τf) of −3 ppm/°C.


2017 ◽  
Vol 898 ◽  
pp. 392-398
Author(s):  
Wen Shiush Chen ◽  
Hsin Han Tung ◽  
Cheng Hsing Hsu ◽  
Ching Fang Tseng ◽  
Chun Hung Lai ◽  
...  

(Ca0.2Sr0.8)3(ZrxTi1-x)2O7 (x = 0.02-0.1) ceramic prepared by the solid state method was investigated for its microstructure and microwave dielectric properties. The correlation between the microstructure and microwave dielectric properties was also investigated. By increasing x from 0.01 to 0.06, the dielectric constant and Q×f value of the specimen could be increased from 72 to a maximum of 74, and from 11000 GHz to a maximum of 18000 GHz, respectively. The εr value of 74, the Q×f value of 18,000 GHz, and the τf value of 418 ppm/oC were obtained for (Ca0.2Sr0.8)3(Zr0.06Ti0.94)2O7 ceramics sintering at 1520oC for 4h, and (Ca0.2Sr0.8)3(ZrxTi1-x)2O7 (x = 0.02-0.1) is proposed as a suitable material candidate for application in microwave ceramic temperature sensing antenna.


2011 ◽  
Vol 01 (02) ◽  
pp. 209-213 ◽  
Author(s):  
S. GEORGE ◽  
V. K. SAJITH ◽  
M. T. SEBASTIAN ◽  
S. RAMAN ◽  
P. MOHANAN

The comparison of the low temperature sintering and the microwave dielectric properties of Li2MgSiO4 (LMS) ceramics prepared by citrate gel (CG) route and solid state (SS) ceramic route are discussed in this paper. The LMS prepared using CG route sintered at 1175°C/2 h has εr = 5.3 and tan δ = 1 × 10−3 at 9 GHz. The sintering temperature of LMS is lowered to 950°C with the addition of 5 wt% lithium magnesium zinc borosilicate glass and has εr = 5.6 and tan δ = 2 × 10-3 at 9 GHz. The amount of glass required to lower the sintering temperature of ceramics prepared using CG are slightly higher than that of SS ceramic route. The LMS ceramics prepared using SS ceramic route shows excellent microwave dielectric properties with low sintering temperature compared to CG route.


2012 ◽  
Vol 499 ◽  
pp. 178-182
Author(s):  
Yi Shan Jiang ◽  
Ying Zi Wang ◽  
Ya Ming Chen ◽  
Yun Long Yue ◽  
Hai Tao Wu

Microwave dielectric ceramics of Mg4Nb2O9were prepared by the solid-state method and their microwave dielectric properties and microstructure were investigated in this study. The sintering ability and microwave dielectric properties of Mg4Nb2O9ceramics were studied under various sintering temperatures ranging from 1200°C to 1350°C. As the sintering temperature increased from 1200°C to 1350°C, the density values, the εr values and the Q·ƒ values increased and saturated at 1350°C.The ƒ values were ranged from -48.7 to -57.8 ppm/°C. Due to the increased density and appropriate grain growth the Mg4Nb2O9ceramics sintered at 1350°C had the excellent microwave dielectric properties of εr=12.3, Q·ƒ =108,000GHz and ƒ=-55.3ppm/°C.


Author(s):  
Ying Xiong ◽  
Hongyuan Xie ◽  
Zhenggang Rao ◽  
Laijun Liu ◽  
Zhengfeng Wang ◽  
...  

AbstractAB2O4-type spinels with low relative permittivity (εr) and high quality factor (Q × f) are crucial to high-speed signal propagation systems. In this work, Zn2+/Ge4+ co-doping to substitute Ga3+ in ZnGa2O4 was designed to lower the sintering temperature and adjust the thermal stability of resonance frequency simultaneously. Zn1+xGa2−2xGexO4 (0.1 ⩽ x ⩽ 0.5) ceramics were synthesised by the conventional solid-state method. Zn2+/Ge4+ co-substitution induced minimal variation in the macroscopical spinel structure, which effectively lowered the sintering temperature from 1385 to 1250 °C. All compositions crystallized in a normal spinel structure and exhibited dense microstructures and excellent microwave dielectric properties. The compositional dependent quality factor was related to the microstructural variation, being confirmed by Raman features. A composition with x = 0.3 shows the best dielectric properties with εr ≈ 10.09, Q × f ≈ 112,700 THz, and τf ≈ −75.6 ppm/°C. The negative τf value was further adjusted to be near-zero through the formation of composite ceramics with TiO2.


Sign in / Sign up

Export Citation Format

Share Document