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).

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.

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.

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.

Low Loss Dielectrics in Ba[(Mg1/3Ta2/3)1−xTix]O3 and Ba[(Mg1−xZnx)1/3Ta2/3]O3 Systems

2005 ◽  
Vol 20 (11) ◽  
pp. 2919-2926 ◽  
Author(s):  
Kuzhichalil Peethambaran Surendran ◽  
Mailadil Thomas Sebastian
Keyword(s):  
Solid Solution ◽  
Dielectric Constant ◽  
Dielectric Properties ◽  
Quality Factor ◽  
Mole Fraction ◽  
Microwave Dielectric Properties ◽  
Quality Factors ◽  
Low Loss ◽  
Microwave Dielectric ◽  
Ti Substitution

The microwave dielectric properties of ceramics based on Ba[(Mg1/3Ta2/3)1−xTix]O3 (BMT-BT) and Ba[(Mg1−xZnx)1/3Ta2/3]O3 (BMT-BZT) were investigated as a function of composition x. In BMT-BT solid solution, the dielectric properties deteriorated with increasing concentration of Ti substitution at the B-site of BMT. A correlation was established between the quality factors of the solid solution phases and their tolerance factor. In BMT-BZT solid solution, where both the end compounds are ordered perovskites, the unit cell expands with increasing mole fraction of the Zn in Mg site of BMT while the dielectric constant increases monotonously from 24.8 (for BMT) to 29.7 (BZT). In BMT-BZT solid solution, the quality factor reaches a maximum (Qu·f = 109,900 GHz) for 60 mol/ of BZT.

Fabrication of Ba6-3x(Sm0.2Nd0.8)8+2xTi18O54(x=2/3) Ceramics by Solid State Reaction

2007 ◽  
Vol 336-338 ◽  
pp. 258-261
Author(s):  
Yong Zheng ◽  
Wen Lei ◽  
Hai Jian Bu ◽  
Xing Zhong Zhao
Keyword(s):  
Dielectric Constant ◽  
Grain Size ◽  
Dielectric Properties ◽  
Solid State ◽  
Resonant Frequency ◽  
Sintering Temperature ◽  
Microwave Dielectric Properties ◽  
Sintered Ceramic ◽  
Temperature Coefficients ◽  
Microwave Dielectric

Effects of calcining and sintering temperatures on the microstructure and the microwave dielectric properties of Ba6-3x(Sm0.2Nd0.8)8+2xTi18O54(x=2/3) ceramics were studied. When the calcining temperature was lower (1373K), the dielectric constant ε and the Qf factor initially increased with increasing sintering temperature, but decreased when sintering temperature was higher than 1603K. As a whole, the temperature coefficients of the resonant frequency τf tended to increase with increasing sintering temperature. The microstructure of the sintered ceramic consisted mainly of columnar and block-shape grains. The grain size increased with increasing sintering temperature. When the calcining temperature was higher (1473K), εr and τf were nearly independent of sintering temperature. The excellent microwave dielectric properties were achieved in the Ba6-3x(Sm0.2Nd0.8)8+2xTi18O54 (x=2/3) ceramic calcined at 1373K and sintered at 1603K for 3 h: ε = 80.8, Qf = 8114 (GHz) and τf = 5.6.

Effects of Nd2O3 on the microwave dielectric properties of BiNbO4 ceramics

1998 ◽  
Vol 13 (10) ◽  
pp. 2945-2949 ◽  
Author(s):  
Whan Choi ◽  
Kyung-Yong Kim ◽  
Myung-Rip Moon ◽  
Kyoo-Sik Bae
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Resonance Frequency ◽  
Sintering Temperature ◽  
Microwave Dielectric Properties ◽  
Positive Direction ◽  
Microwave Dielectric ◽  
Triclinic Phase ◽  
Nd Substitution ◽  
Peak Value

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.

Structures and microwave dielectric properties of Ba6−3x(Nd,Biy)8+2xTi18O54 (x = 2/3) solid solution

2001 ◽  
Vol 16 (6) ◽  
pp. 1734-1738 ◽  
Author(s):  
Yong Jun Wu ◽  
Xiang Ming Chen
Keyword(s):  
Solid Solution ◽  
Dielectric Properties ◽  
Resonant Frequency ◽  
Temperature Coefficient ◽  
Solid Solubility ◽  
Microwave Dielectric Properties ◽  
Solubility Limit ◽  
Solid Solubility Limit ◽  
Continuous Increase ◽  
Microwave Dielectric

The effects of Bi substitution for Nd in Ba6−3xNd8+2xTi18O54 (x = 2/3) solid solution upon the microstructures and microwave dielectric properties were investigated. The solid solubility limit of Bi in Ba6−3xNd8+2xTi18O54 (x = 2/3) solid solution was about 15 mol%, the same as that for x = 0.5, and densification of the present solid solutions could be performed well at lower temperatures. However, the variation tendency of microwave dielectric properties with composition in the present ceramics quite differed from that for x = 0.5: (1) The temperature coefficient of resonant frequency in the present ceramics showed a continuous variation from positive to negative and did not indicate extreme value at the solid solubility limit. (2) Near-zero temperature coefficient of resonant frequency combined with high-ε and high-Qf values could be obtained in the present ceramics, while that for x = 0.5 had a lower limit of +15 ppm/°C. (3) The dielectric constant also showed a continuous increase for the present compositions, while that in x = 0.5 had an extreme at solid solubility limit. Ceramics with composition of Ba6−3x(Nd0.85,Bi0.15)8+2xTi18O54 (x = 2/3) showed excellent dielectric properties of ε = 99.1, Qf = 5290 GHz, and τf = −5.5 ppm/°C.

Dielectric properties of La-substituted Pb0.5Ca0.5[(Mg1/3Nb2/3)0.5Ti0.5]O3 ceramics

2001 ◽  
Vol 16 (7) ◽  
pp. 2053-2056
Author(s):  
X. J. Lu ◽  
X. M. Chen
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Resonant Frequency ◽  
Temperature Coefficient ◽  
Microwave Dielectric Properties ◽  
Present Approach ◽  
Calculated Temperature ◽  
Microwave Dielectric ◽  
La Substitution ◽  
Dielectric Ceramics

Modification of Pb0.5Ca0.5[(Mg1/3Nb2/3)0.5Ti0.5]O3 dielectric ceramics was performed by up to 20 mol% La substitution for Pb and Ca. The temperature coefficient of dielectric constant was significantly reduced by the present approach, while an increased Qf factor was achieved. Good microwave dielectric properties were obtained in a composition Pb0.425Ca0.425La0.1[(Mg1/3Nb2/3)0.5Ti0.5]O3: ε = 125; Qf = 3150 GHz; calculated temperature coefficient of resonant frequency δf = +253 ppm/°C.

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.

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