Effects of ZnO Addition and Sintering Temperature on Dielectric Properties of MgTiO3 Ceramic

2014 ◽  
Vol 616 ◽  
pp. 145-152 ◽  
Author(s):  
Xiao Li Ji ◽  
Fang Yi ◽  
Song Zhang ◽  
Cheng C. Zhai ◽  
Peng Fei Hu

The effects of ZnO addition and sintering temperature on dielectric properties of MgTiO3 ceramics were investigated. The results showed that addition ZnO not only reduce the sintering temperature but also improve the density and dielectric properties of MgTiO3 ceramics. (Mg1-xZnx)TiO3 (MZT) ceramics shows microwave dielectric properties in a wide range of sintering temperature when x = 0.1, 0.2, 0.3. At x ≥ 0.4, the density of ceramics decreased and porosity, defects and glass phase increased with increased doping of ZnO, resulting in the increase of dielectric loss of MZT and reduce of quality factor.

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.


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.


2010 ◽  
Vol 25 (12) ◽  
pp. 2380-2383 ◽  
Author(s):  
Yi Zeng ◽  
Hong Wang ◽  
Huanfu Zhou

The effect of BaCu(B2O5) (BCB) on the sintering temperature and microwave dielectric properties of Ba(Nd0.8Bi0.2)2Ti4O12 (BNBT) ceramics was investigated. The sintering temperature of the BNBT ceramics was significantly reduced from 1300 to 900 °C. Due to adding BCB into Ba(Nd1–xBix)2Ti4O12, the temperature coefficient of resonant frequency can be adjusted to zero with BCB content increasing. Good microwave dielectric properties of quality factor (Q×f) = 2600 GHz, εr = 75, and τf = 5 ppm/°C were obtained for BNBT with 7 wt% BCB sintered at 925 °C for 2 h, which make it a potential candidate for low temperature cofired ceramics applications.


2006 ◽  
Vol 966 ◽  
Author(s):  
Hongtao Yu ◽  
Hua Hao ◽  
Hanxing Liu ◽  
Zhongqing Tian

ABSTRACTThe effect of CuO on the microstructure and microwave dielectric properties of the CaTiO3-Ca(Zn1/3Nb2/3)O3 ceramics prepared by the conventional solid-method has been investigated. Doped with the 0.5∼1.25wt% CuO powder, the system of which the sintering temperatures were lowered exhibited the orthorhombic perovskite. It can effectively promote the microwave dielectric properties of the 0.3CaTiO3-0.7Ca(Zn1/3Nb2/3)O3 system at lower sintering temperature at the level of 1.0wt% CuO additive. The quality factor increases from 10860 to 13900GHz and not any significant change was observed in the TCF value with fixed CuO additive at different sintering temperature.


2012 ◽  
Vol 476-478 ◽  
pp. 940-943 ◽  
Author(s):  
Zhong Yan ◽  
Jin Liang Huang ◽  
Yong Jun Gu ◽  
Biao Jin ◽  
Ru Yu Wang

ZnNb2O6 ceramics doped with V2O5 were prepared by conventional mixed solid method. The effects of V2O5 addition on the microstructure and the microwave dielectric properties of ZnNb2O6 ceramics were investigated systematically. The sintering temperature of ZnNb2O6 ceramics with 1.0wt.% V2O5 addition can be effectively reduced from 1150°C to 1050°C. The secondary phase ZnV2O6 was observed in sintered samples with V2O5 addition content higher than 1.0wt.%. For 0.3–3wt.%V2O5-doped ZnNb2O6 ceramics, The dielectric constants (εr) of densified samples were higher than that of undoped ZnNb2O6 ceramics. The temperature coefficient of resonant frequency (τf) were shifted toward zero direction with the increase of V2O5 addition, However, the dielectric loss (tanδ=1/Q) increased. The 1.0wt.% V2O5-doped ZnNb2O6 ceramics sintered at 1050°C for 3h have the optimum microwave dielectric properties: εr=28, tanδ=0.0006 and τf=-42.5 ppm/°C.


2003 ◽  
Vol 783 ◽  
Author(s):  
Cheng-Liang Huang ◽  
Yuan-Bin Chen ◽  
Ching-Wen Lo

ABSTRACTThe microwave dielectric properties of (1-x)CaTiO3-xNd(Mg1/2Ti1/2)O3 (0.1≤x≤1.0) have been investigated. The system forms a solid solution throughout the entire compositional range. The dielectric constant decreases from 152 to 27 as x varies from 0.1 to 1.0. In the (1-x)CaTiO3-xNd(Mg1/2Ti1/2)O3 system, the microwave dielectric properties can be effectively controlled by varying the x value. A maximum quality factor Qxf=43000GHz (where f is the resonant frequency) was achieved for samples with x=0.9, although the dielectric properties varied with sintering temperature. The Qxf value of (1-x)CaTiO3-xNd(Mg1/2Ti1/2)O3 almost increased up to 1500°C, after which it decreased. At 1400°C, 0.1CaTiO3-0.9Nd(Mg1/2Ti1/2)O3 ceramics gives a dielectric constant εr of 42, a Qxf value of 35000 (GHz) and a τf value of -10 (ppm/°C).


Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 438
Author(s):  
Shuwei Yang ◽  
Bingliang Liang ◽  
Changhong Liu ◽  
Jin Liu ◽  
Caisheng Fang ◽  
...  

The (1–x)Ca0.61La0.26TiO3-xNd(Mg0.5Ti0.5)O3 [(1–x)CLT-xNMT, x = 0.35~0.60] ceramics were prepared via microwave sintering. The effects of sintering temperature and composition on the phase formation, microstructure, and microwave dielectric properties were investigated. The results show that the microwave sintering process requires a lower sintering temperature and shorter sintering time of (1–x)CLT-xNMT ceramics than conventional heating methods. All of the (1–x)CLT-xNMT ceramics possess a single perovskite structure. With the increase of x, the dielectric constant (ε) shows a downward trend; the quality factor (Qf) drops first and then rises significantly; the resonance frequency temperature coefficient (τf) keeps decreasing. With excellent microwave dielectric properties (ε = 51.3, Qf = 13,852 GHz, τf = −1.9 × 10−6/°C), the 0.65CLT-0.35NMT ceramic can be applied to the field of mobile communications.


2011 ◽  
Vol 326 ◽  
pp. 127-130
Author(s):  
Xian Li Huang ◽  
Fu Ping Wang ◽  
Ying Song

In the present work, the microstructure and microwave dielectric properties of BaTi4O9 ceramics derived from a sol-gel precursor were presented. Density measuring results demonstrated that the largest densities of ceramic sample about 96.7% could be reached by virtue of a cool iso-static press and a sintering process at at 1300 °C for 6 hours. The dielectric constant (εr), quality factor (Q×f) and the temperature coefficients (τf) of the BaTi4O9 ceramic samples were 36.65, 28000 GHz, +20.2 ppm/°C, respectively. XRD, SEM and XPS were used to characterize the microstructure of the ceramics samples. Substantial Ti3+ was proposed to be the cause of dielectric loss.


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