Effect of CuO on Microstructure and Microwave Dielectric Properties of CaTiO3-Ca(Zn1/3Nb2/3)O3 Ceramics System

2006 ◽  
Vol 966 ◽  
Author(s):  
Hongtao Yu ◽  
Hua Hao ◽  
Hanxing Liu ◽  
Zhongqing Tian
Keyword(s):  
Dielectric Properties ◽  
Quality Factor ◽  
Sintering Temperature ◽  
Microwave Dielectric Properties ◽  
Microwave Dielectric ◽  
Orthorhombic Perovskite ◽  
Significant Change

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.

Microwave dielectric properties of Ca[(Li1/3Nb2/3)1−xMx]O3−δ (M = Sn, Ti) ceramics

1999 ◽  
Vol 14 (9) ◽  
pp. 3567-3570 ◽  
Author(s):  
Ji-Won Choi ◽  
Chong-Yun Kang ◽  
Seok-Jin Yoon ◽  
Hyun-Jai Kim ◽  
Hyung-Jin Jung ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Resonant Frequency ◽  
Temperature Coefficient ◽  
Quality Factor ◽  
Single Phase ◽  
Microwave Dielectric Properties ◽  
Multiphase Materials ◽  
Microwave Dielectric ◽  
Orthorhombic Perovskite

The microwave dielectric properties of Ca[(Li1/3Nb2/3)1−xMx]O3−δ (M = Sn, Ti, 0 ≤ x ≤ 0.5) ceramics were investigated. In general, the ceramics prepared were multiphase materials. However, single-phase specimens having orthorhombic perovskite structure similar to CaTiO3 could be obtained in the vicinity of Sn = 0.2 to 0.3, and Ti = 0.2. As Sn concentration increased, the dielectric constant (εr) decreased and the quality factor (Q) significantly increased within the limited Sn concentration. As Ti concentration increased, the dielectric constant (εr) increased, the quality factor (Q) decreased, and the temperature coefficient of resonant frequency (τf) changed from a negative to positive value. The temperature coefficient of resonant frequency of 0 ppm/°C was realized at Ti = 0.2. The Q · fo value and εr for this composition were found to be 26100 GHz and 38.6, respectively.

Effects of CuO and V2O5 Addition on Sintering Behavior and Microwave Dielectric Properties of (1-x)Ca2P2O7-xTiO2

2007 ◽  
Vol 336-338 ◽  
pp. 279-282
Author(s):  
In Sun Cho ◽  
Sang Gu Kang ◽  
Dong Wan Kim ◽  
Kug Sun Hong
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Resonant Frequency ◽  
Temperature Coefficient ◽  
Quality Factor ◽  
Sintering Temperature ◽  
Microwave Dielectric Properties ◽  
Sintering Behavior ◽  
Microwave Dielectric

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.

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
Keyword(s):  
Dielectric Properties ◽  
Dielectric Loss ◽  
Quality Factor ◽  
Glass Phase ◽  
Sintering Temperature ◽  
Microwave Dielectric Properties ◽  
Microwave Dielectric ◽  
Wide Range ◽  
Porosity Defects

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.

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.

Microwave Dielectric Properties of (Ca0.8Sr0.2)x(Li0.5Nd0.5)1-xTiO3 Ceramics

2015 ◽  
Vol 1095 ◽  
pp. 583-589
Author(s):  
Yun Yang ◽  
Chang Lai Yuan ◽  
Guo Hua Chen ◽  
Fu Wei Peng ◽  
Tao Yang
Keyword(s):  
Solid Solution ◽  
Dielectric Properties ◽  
Unit Cell Volume ◽  
Composition Range ◽  
Sintering Temperature ◽  
Microwave Dielectric Properties ◽  
Practical Application ◽  
Ceramic System ◽  
Microwave Dielectric ◽  
Orthorhombic Perovskite

Microwave dielectric properties and microstructures have been investigated in the x Ca0.8Sr0.2TiO3 − (1−x) Li0.5Nd0.5TiO3 ceramic system. In the entire composition range, a single solid solution in the ceramic system was formed with the orthorhombic perovskite structure. As the Ca0.8Sr0.2TiO3 content of the ceramic system increased from 0.1 to 0.3, the dielectric constant (εr) increased from 114 to 144, the product (Qf) of quality factor (Q) and frequency (f) from 995 to 1,121 GHz, and the temperature coefficient of resonant frequency (τf) value from-83 to 94 ppm/°C, respectively. Simultaneously, the observed polarizabilities and the theoretical polarizability increased with rise in the Ca0.8Sr0.2TiO3 content. The τf value increased linearly with the increasing unit-cell volume. For practical application, a near-zero τf in the 0.2Ca0.8Sr0.2TiO3 −0.8Li0.5Nd0.5TiO3 ceramic with a Qf value of 1,025 GHz and a εr value of 132 were obtained at the sintering temperature of 1300°C for 4 h.

Effect of BaCu(B2O5) on the sintering temperature and microwave dielectric properties of Ba(Nd0.8Bi0.2)2Ti4O12 ceramics

2010 ◽  
Vol 25 (12) ◽  
pp. 2380-2383 ◽  
Author(s):  
Yi Zeng ◽  
Hong Wang ◽  
Huanfu Zhou
Keyword(s):  
Dielectric Properties ◽  
Low Temperature ◽  
Resonant Frequency ◽  
Temperature Coefficient ◽  
Quality Factor ◽  
Sintering Temperature ◽  
Microwave Dielectric Properties ◽  
Potential Candidate ◽  
Microwave Dielectric ◽  
Quality Factor Q

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.

Crystal Structure and Microwave Dielectric Properties of Ca[(Li1/3Nb2/3)0.95Zr0.15]O3+δ Ceramics with Pr3+ Substitution at A-Site

2011 ◽  
Vol 181-182 ◽  
pp. 439-442
Author(s):  
Gang Xiong
Keyword(s):  
Crystal Structure ◽  
Dielectric Properties ◽  
Quality Factor ◽  
Perovskite Structure ◽  
Single Phase ◽  
Microwave Dielectric Properties ◽  
Microwave Dielectric ◽  
Resonator Frequency ◽  
Orthorhombic Perovskite ◽  
A Site

Crystal structure and microwave dielectric properties of (Ca1-xPrx) [(Li1/3Nb2/3)0.95Zr0.15]3+δ (0.0≤x≤0.2, CPLNZ) ceramics were investigated. A single phase with orthorhombic perovskite structure was obtained at x=0.0~0.08. With an increase of Pr3+ content, the quality factor value firstly increased, and then began to decrease at x=0.06 due to a decrease of the degree of B-site 1:2 ordering. The variation of τf with tolerance factor was discussed. When x=0.06, the optimum microwave dielectric properties: the permittivity is 33.2, the quality factor is 17120 GHz，and the temperature coefficient of resonator frequency is −5.7×10−6/°C.

Microwave Dielectric Properties of Ca[(Li1/3Nb2/3)0.95Zr0.15]O3+δ Ceramics with Sm3+ Substitution at A-Site

2010 ◽  
Vol 663-665 ◽  
pp. 698-701
Author(s):  
Gang Xiong
Keyword(s):  
Crystal Structure ◽  
Dielectric Properties ◽  
Quality Factor ◽  
Perovskite Structure ◽  
Single Phase ◽  
Microwave Dielectric Properties ◽  
Microwave Dielectric ◽  
Resonator Frequency ◽  
Orthorhombic Perovskite ◽  
A Site

Crystal structure and microwave dielectric properties of (Ca1-xSmx) [(Li1/3Nb2/3)0.95Zr0.15]3+δ(0.0≤x≤0.2,CSLNZ) ceramics were investigated. A single phase with orthorhombic perovskite structure was obtained at x=0.0~0.08. With an increase of Sm3+ content, the quality factor value firstly increased, and then began to decrease at x=0.03 due to a decrease of the degree of B-site 1:2 ordering. The variation of τf with tolerance factor was discussed. When x=0.05, the optimum microwave dielectric properties: the permittivity is 32.4，the quality factor is 16560GHz，and the temperature coefficient of resonator frequency is −6.3×10−6/°C。

Micr owave Dielectric Properties of (1-x)CaTiO3-xNd(Mg1/2Ti1/2)O3 Ceramics System

2003 ◽  
Vol 783 ◽  
Author(s):  
Cheng-Liang Huang ◽  
Yuan-Bin Chen ◽  
Ching-Wen Lo
Keyword(s):  
Solid Solution ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Resonant Frequency ◽  
Quality Factor ◽  
Sintering Temperature ◽  
Microwave Dielectric Properties ◽  
Compositional Range ◽  
Microwave Dielectric

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).

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