Effects of MnO2 and WO3 co-doping and sintering temperature on microstructure, microwave dielectric properties of Ba2Ti9O20 microwave ceramics

2021 ◽  
Author(s):  
Cong Ji ◽  
Jie Wang ◽  
Xue Bai ◽  
Mengmeng Hao ◽  
Gang Chen ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Sintering Temperature ◽  
Microwave Dielectric Properties ◽  
Microwave Ceramics ◽  
Co Doping ◽  
Microwave Dielectric

Low-Temperature Firing and Microwave Dielectric Properties of Zn3Nb2O8 Ceramics with CuO-V2O5-Bi2O3

2010 ◽  
Vol 434-435 ◽  
pp. 224-227
Author(s):  
Xu Ping Lin ◽  
Jing Tao Ma ◽  
Bao Qing Zhang ◽  
Ji Zhou
Keyword(s):  
Dielectric Constant ◽  
Phase Composition ◽  
Dielectric Properties ◽  
Relative Density ◽  
Sintering Temperature ◽  
Microwave Dielectric Properties ◽  
Sintering Behavior ◽  
Co Doping ◽  
Microwave Dielectric ◽  
Quality Factor Q

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.

scholarly journals Compositional modulation in ZnGa2O4 via Zn2+/Ge4+ co-doping to simultaneously lower sintering temperature and improve microwave dielectric properties

2021 ◽  
Author(s):  
Ying Xiong ◽  
Hongyuan Xie ◽  
Zhenggang Rao ◽  
Laijun Liu ◽  
Zhengfeng Wang ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Quality Factor ◽  
Spinel Structure ◽  
High Speed ◽  
Sintering Temperature ◽  
Microwave Dielectric Properties ◽  
Signal Propagation ◽  
Solid State Method ◽  
Co Doping ◽  
Microwave Dielectric

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.

Effects of zinc substitution on the dielectric properties of Ca5Nb4TiO17 microwave ceramics

2013 ◽  
Vol 03 (04) ◽  
pp. 1320003 ◽  
Author(s):  
Chunchun Li ◽  
Xiaoyong Wei ◽  
Haixue Yan ◽  
Michael J. Reece
Keyword(s):  
Dielectric Properties ◽  
Sintering Temperature ◽  
Microwave Dielectric Properties ◽  
Solid State Reaction Method ◽  
Sintering Behavior ◽  
Potential Candidate ◽  
Strongly Correlated ◽  
Microwave Ceramics ◽  
Microwave Dielectric ◽  
Method Effects

Ca 5-x Zn x Nb 4 TiO 17 ceramics with 0 ≤ x ≤ 0.4 were prepared through a solid-state reaction method. Effects of zinc substitution on sintering behavior and microwave dielectric properties of Ca 5 Nb 4 TiO 17 ceramics were investigated. The sintering temperature was significantly lowered from 1480°C for pure Ca 5 Nb 4 TiO 17 to 1260°C for x = 0.4. The microwave dielectric properties are strongly correlated with the composition. It is worth noting that the temperature coefficient of resonant frequency (τf) displays a tendency toward positive value, ranging from −126.4 ppm/°C to −8.6 ppm/°C. A temperature stable microwave ceramic with dielectric constant of 52 and Q × f value of 9937 GHz is achieved at x = 0.4 and is a potential candidate for application as cores in dielectrically loaded antennas.

Effect of Glass Additions on Ca[(Li1/3Nb2/3)0.92Zr0.08]O3−δ Microwave Ceramics

2012 ◽  
Vol 535-537 ◽  
pp. 805-808
Author(s):  
Hui Xiong ◽  
Gang Xiong ◽  
Cui Hua She
Keyword(s):  
Dielectric Properties ◽  
Temperature Coefficient ◽  
Sintering Temperature ◽  
Microwave Dielectric Properties ◽  
Glass Content ◽  
Microwave Ceramics ◽  
Microwave Dielectric ◽  
Resonator Frequency

The effects of ZnO-B2O3-Na2O(ZBN) glass on the sinterability and microwave dielectric properties of Ca[(Li1/3Nb2/3)0.92Zr0.08]O3−δ ceramics were investigated . ZBN glass doping can effectively reduce sintering temperatue by 100~150°C. The temperature coefficient of resonator frequency τf increased with an increase of ZBN glass content and sintering temperatue. When ZBN glass of 1.8wt% were added, the optimum microwave dielectric properties: εr =22.1,Qf =18360GHz and τf = − 9.8×10−6/°C were obtained at the sintering temperature of 1000°C.

Research on sintering behavior and microwave dielectric property of (Mg0.95Ca0.05)TiO3 ceramics for cross coupling filter

2015 ◽  
Vol 29 (34) ◽  
pp. 1550220 ◽  
Author(s):  
Chunya Luo ◽  
Zhichao Ma ◽  
Laisheng Hu ◽  
Mingzhe Hu ◽  
Xiaomin Huang
Keyword(s):  
Dielectric Properties ◽  
Sintering Temperature ◽  
Microwave Dielectric Properties ◽  
Cross Coupling ◽  
Center Frequency ◽  
Sintering Behavior ◽  
Co Doping ◽  
Microwave Dielectric ◽  
Dielectric Filter ◽  
Liquid Sintering

The microwave dielectric properties of [Formula: see text]–[Formula: see text] (abbreviated as 95MCT hereafter) ceramics have been studied for application in dielectric cross coupling filters. [Formula: see text] and [Formula: see text] were selected as liquid sintering aids to lower the sintering temperature and enhance the Qf value of 95MCT and simultaneously we varied the mole ratio of [Formula: see text] to tune the microwave dielectric properties of 95MCT. When the [Formula: see text] mole ratio was 1.5 and the co-doping content was 0.25 wt.%, the optimal sintering temperature of 95MCT ceramic could be lowered from [Formula: see text] to [Formula: see text] and the Qf value could be improved by about 7.7%. The optimal microwave dielectric properties obtained under this condition were Qf = 72730 GHz (6.8 GHz), [Formula: see text] and [Formula: see text], which demonstrated great potential usage in ceramic industry. High values of Qf ceramic were used to design the dielectric cross coupling filter. The dielectric filter measured at 2.35 GHz exhibited a 6.7% bandwidth (insert loss [Formula: see text] dB) of center frequency.

Effect of ZnO-V2O5 Co-Doping on Phase Stability and Microwave Dielectric Properties of ZnTiO3 Ceramics

2007 ◽  
Vol 336-338 ◽  
pp. 297-300 ◽  
Author(s):  
Jing Yan ◽  
Zhen Xing Yue ◽  
Jin Wang ◽  
Fei Zhao ◽  
Zhi Lun Gui ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Low Temperature ◽  
Sintering Temperature ◽  
Microwave Dielectric Properties ◽  
Sintering Process ◽  
Quality Factors ◽  
Zinc Titanate ◽  
Co Doping ◽  
Microwave Dielectric ◽  
Titanate Ceramics

Zinc titanate ceramics having excellent dielectric properties and low sintering temperature are promising materials for RF/microwave multilayer devices. In this paper, the ZnO-V2O5 addition was added to promote the sintering process in order to obtain low-temperature sintered ceramics with high quality factors. The sintering addition could also restrain ZnTiO3 phase from decomposition. Using this method, low-temperature sintered zinc titanate ceramics with excellent microwave dielectric properties of εr~ 25.3, Q×f~15200GHz, and τf ~ -16 ppm/oC were obtained at sintering temperature of 800oC. The low-fired mechanism, microstructure, phase formation and microwave dielectric properties of ceramics were investigated by XRD, SEM, EDS and network analysis techniques, respectively.

Influence of ZnO and Nb2O5 Additions on Sintering Behavior and Microwave Dielectric Properties of (Mg0.95Ca0.05 )TiO3 Ceramics

2012 ◽  
Vol 512-515 ◽  
pp. 1184-1188 ◽  
Author(s):  
Chun Ya Luo ◽  
Ming Zhe Hu ◽  
Quian Huang ◽  
Yang Fu ◽  
Hao Shuang Gu
Keyword(s):  
Dielectric Properties ◽  
Oxygen Vacancies ◽  
Sintering Temperature ◽  
Microwave Dielectric Properties ◽  
Secondary Phase ◽  
Sintering Behavior ◽  
Doping Content ◽  
Co Doping ◽  
Microwave Dielectric ◽  
Xrd Patterns

The influence of ZnO and Nb2O5 additions on the sinterability, microstructure and microwave dielectric properties of (Mg0.95Ca0.05)TiO3 (abbreviated as 95MCT hereafter) ceramic is investigated. XRD patterns indicate that MgTi2O5 secondary phase can be effectively suppressed by ZnO and Nb2O5 additions, which is beneficial for improving the microwave dielectric properties. Appropriate amount of Nb2O5 addition can effectively improve the Qf value of 95MCT ceramic, which is suggested to be ascribed to the reduced oxygen vacancies. When the ZnO: Nb2O5 mole ratio is 1.5 and the co-doping content is 0.25wt%, the optimal microwave dielectric properties can be obtained Qf=72730GHz(6.8GHz), εr=20.29 and τf=-6.84ppm/°C and the sintering temperature of 95MCT is lowered from 1400°C to 1320°C.

Preparation and Dielectric Properties of BaO-Sm2O3-4TiO2 Microwave Ceramics with B2O3 and CuO Addition Sintered in Low Temperature

2008 ◽  
Vol 368-372 ◽  
pp. 173-175 ◽  
Author(s):  
Wei Liang Liu ◽  
Chun Bao Tang ◽  
Jun Tan ◽  
Du Song Mao ◽  
Jin Gang Tan
Keyword(s):  
Dielectric Properties ◽  
Sintering Temperature ◽  
Tungsten Bronze ◽  
Microwave Dielectric Properties ◽  
Microwave Dielectric Ceramics ◽  
Microwave Ceramics ◽  
Sintering Aid ◽  
Microwave Dielectric ◽  
Bst Ceramics ◽  
Dielectric Ceramics

BaCu(B2O5) (BCB) powder was prepared using BaO,CuO and B2O3 as the main materials. Microwave dielectric ceramics of tungsten–bronze-type BaSm2Ti4O12 (BST) were prepared by doping BCB as the sintering aid. The amount of BCB was varied from 1.0 to 10.0wt.%. The microstructure and dielectric properties of BST were investigated. The sintering temperature of BST ceramics with 6.0wt.% BCB addition can be effectively reduced to 900 oC, about 450 oC lower than that of pure BST ceramics. Good microwave dielectric properties of εr = 62.38, Q×f = 4573 GHz and τf = -27.65 ppm/ oC were achieved.

scholarly journals Microwave Sintering and Microwave Dielectric Properties of (1–x)Ca0.61La0.26TiO3-xNd(Mg0.5Ti0.5)O3 Ceramics

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 438
Author(s):  
Shuwei Yang ◽  
Bingliang Liang ◽  
Changhong Liu ◽  
Jin Liu ◽  
Caisheng Fang ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Mobile Communications ◽  
Sintering Temperature ◽  
Microwave Sintering ◽  
Microwave Dielectric Properties ◽  
Conventional Heating ◽  
Sintering Process ◽  
Microwave Dielectric ◽  
Sintering Time ◽  
Frequency Temperature

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.

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