Effect of V2O5 and ZnO Additives on the Sintering Temperature and Microwave Dielectric Properties of Ca[(Li1/3Nb2/3) 0.8Ti 0.2]O3-δ Ceramics

2011 ◽  
Vol 239-242 ◽  
pp. 77-80 ◽  
Author(s):  
Ji Hong Liao ◽  
Ying Dai ◽  
Ren Zhou Yang ◽  
Wen Chen
Keyword(s):  
Dielectric Properties ◽  
Sintering Temperature ◽  
Microwave Dielectric Properties ◽  
Solid State Reaction Method ◽  
Sintering Behavior ◽  
Conventional Solid State Reaction ◽  
Microwave Dielectric ◽  
Diffraction Peaks ◽  
Dielectric Ceramics ◽  
The Relationship

Low-temperature sintered Ca[(Li1/3Nb2/3)0.8Ti0.2]O3-δ (CLNT) microwave dielectric ceramics with V2O5 and ZnO additives were prepared by the conventional solid state reaction method. The sintering behavior and microwave dielectric properties of CLNT ceramics were investigated. The main diffraction peaks of all the specimens sintered at the temperature under 1150◦C split due to the coexistence of the non-stoichiometric phase and stoichiometric phase, which all possess CaTiO3-type perovskite structures. ZnO and V2O5 combined additives lowered the sintering temperature of CLNT ceramics from 1150◦C to 1090◦C. and the Qf values were improved from 18,210 GHz to 20,740 GHz. The CLNT ceramics with 4 wt% ZnO addition sintered at 1090◦C showed good microwave dielectric properties with εr ~39.7, Qf ~20,740 GHz, τf ~8.6 ppm/◦C. The relationship between dielectric properties and the sintering behavior was also discussed.

Low Temperature Sintering of (Ca0.9375Sr0.0625)0.25(Li0.5Sm0.5)0.75TiO3 Microwave Dielectric Ceramics

2010 ◽  
Vol 663-665 ◽  
pp. 1028-1031
Author(s):  
Yue Ming Li ◽  
Hua Zhang ◽  
Zhu Mei Wang ◽  
Yan Hong ◽  
Zong Yang Shen
Keyword(s):  
Dielectric Properties ◽  
Low Temperature ◽  
Sintering Temperature ◽  
Microwave Dielectric Properties ◽  
Sintering Behavior ◽  
Low Temperature Sintering ◽  
Microwave Dielectric Ceramics ◽  
Microwave Dielectric ◽  
Dielectric Ceramics

The sintering behavior and microwave dielectric properties of the (Ca0.9375Sr0.0625)0.25(Li0.5Sm0.5)0.75TiO3 (CSLST) ceramics doped with different amounts of Li2O-B2O3-SiO2-CaO-Al2O3 (LBSCA) glass were investigated. The sintering temperature of the CSLST ceramics can be effectively reduced over 200oC due to the addition of LBSCA glass. For the 5 wt% LBSCA-doped CSLST ceramics, which are sintered at only 1000 oC for 5 h, show optimum microwave dielectric properties as follows: εr=84.74, Qf=2446 GHz and τf=-12.48 ppm/oC.

Effect of H3BO3 Additive and Forming Pressure on Microwave Dielectric Properties of 0.95MgTiO3-0.05CaTiO3

2014 ◽  
Vol 941-944 ◽  
pp. 521-524
Author(s):  
Jin Bao Huang ◽  
Yi Xiang Cai ◽  
Zhao Xian Xiong ◽  
Hao Xue
Keyword(s):  
Dielectric Properties ◽  
Sintering Temperature ◽  
Microwave Dielectric Properties ◽  
Solid State Reaction Method ◽  
Sintering Process ◽  
Microwave Dielectric ◽  
Method Effect ◽  
Best Value ◽  
Dielectric Ceramics ◽  
Quality Factor Q

0.95MgTiO3-0.05CaTiO3 (95MCT) microwave dielectric ceramics was prepared solid-state reaction method. Effect of H3BO3 additive and forming pressure on sintering process, microstructure and microwave dielectric properties of 95MCT were investigated. The result showed that the additive of H3BO3 can lower the sintering temperature of 95MCT, and improve the densification of 95MCT. MgTi2O5 was found as mesosphere, which can be effectively suppressed through the additive of H3BO3. Excellent microwave dielectric properties of ceramics was obtained when the H3BO3 additive was 0.50wt%. The best value of dielectric constant (εr), quality factor (Q×f) and temperature coefficient of resonant frequency (τf ) of 21.54, 67,286GHz and-4.1ppm/oC was obtained for the ceramics with sintering 1220oC for 2h.

scholarly journals SINTERING BEHAVIOR AND MICROWAVE DIELECTRIC PROPERTIES OF NOVEL LOW TEMPERATURE FIRING Bi3FeMo2O12 CERAMIC

2011 ◽  
Vol 01 (04) ◽  
pp. 379-382 ◽  
Author(s):  
DI ZHOU ◽  
LI-XIA PANG ◽  
JING GUO ◽  
YING WU ◽  
GAO-QUN ZHANG ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Low Temperature ◽  
Sintering Temperature ◽  
Microwave Dielectric Properties ◽  
Solid State Reaction Method ◽  
Sintering Behavior ◽  
Reaction Method ◽  
Temperature Firing ◽  
Microwave Dielectric ◽  
Dielectric Performance

In the present work, a novel low temperature firing Bi 3 FeMo 2 O 12 ceramic was synthesized via the solid-state reaction method. The monoclinic Bi 3 FeMo 2 O 12 phase can be formed at a low temperature 670°C. A relative density above 96% can be obtained when sintering temperature is above 800°C. The Bi 3 FeMo 2 O 12 ceramic sintered at 845°C for 2 h shows high microwave dielectric performance with a permittivity ~27.2, a Qf value of 14,500 GHz and a temperature coefficient of -80 ppm/°C. It might be a candidate for low temperature co-fired ceramics technology.

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.

Preparation and Microwave Dielectric Properties of Ca(Sm0.5Nb0.5)O3 Ceramics

2012 ◽  
Vol 512-515 ◽  
pp. 1198-1202
Author(s):  
Jia Mao Li ◽  
Tai Qiu
Keyword(s):  
Dielectric Properties ◽  
Solid State ◽  
Cooling Rate ◽  
Sintering Temperature ◽  
Microwave Dielectric Properties ◽  
Solid State Reaction Method ◽  
Sintering Process ◽  
Conventional Solid State Reaction ◽  
Reaction Method ◽  
Microwave Dielectric

Microstructures and microwave dielectric properties of Ca(Sm0.5Nb0.5)O3 ceramics, prepared by a conventional solid-state reaction method, were systematically investigated by varying calcining temperature, sintering temperature and cooling rate. The XRD result showed that a single Ca(Sm0.5Nb0.5)O3 phase could be synthesized at a calcining temperature of 1200 °C. Optimized combination of microwave dielectric properties of εr = 22.36, Q×f = 18030 GHz and τf = -31.2 ppm/°C was obtained for furnace-cooled Ca(Sm0.5Nb0.5)O3 ceramics sintered at 1550 °C for 4 h. However, some microcracks were found from the microstructures of the furnace-cooled specimens. Further, the Q×f value could be increased by controlling the cooling rate during the sintering process due to the disappearance of microcracks in the final material. With a cooling rate of 2 °C/min, Ca(Sm0.5Nb0.5)O3ceramics exhibited an enhanced Q×f value of 37130 GHz.

Effect of CuO-Bi2O3 Co-Doping on Microwave Dielectric Properties of Ba4Sm9.33Ti18O54 Ceramics

2011 ◽  
Vol 197-198 ◽  
pp. 548-551
Author(s):  
Zhi Lan Tang ◽  
Chun Ying Shen ◽  
Zhao Xi Li ◽  
Jian Yang ◽  
Tai Qiu
Keyword(s):  
Dielectric Properties ◽  
Microwave Dielectric Properties ◽  
Solid State Reaction Method ◽  
Liquid Phase Sintering ◽  
Sintering Behavior ◽  
Conventional Solid State Reaction ◽  
Co Doping ◽  
Microwave Dielectric ◽  
Bst Ceramics ◽  
Quality Factor Q

Ba4Sm9.33Ti18O54(BST) ceramics were prepared by conventional solid-state reaction method. The effect of CuO-Bi2O3co-doping on the sintering behavior and microwave dielectric properties of BST ceramics has been investigated. The results indicated that when the total addition of CuO-Bi2O3doping agent was 1.0wt%, the sintering temperature of BST ceramics was reduced to 1240°C as a result of liquid-phase sintering effect derived from CuBi2O4. When the total addition of CuO-Bi2O3was fixed at 1.0wt%, the microwave dielelctric properties of BST were improved by adjusting the mass percentage of Bi2O3. With the increase of Bi2O3amount from 20wt% to 80wt%, the dielectric constant (εr) decreased, the quality factor (Q•f) increased and the temperature coefficient of resonant frequency (τf) shifted from negative value to positive value. The excellent microwave dielectric properties of εr=82.51, Q•f=7878GHz and τf=+6.02ppm/ were obtained for the sample with Bi2O3amount of 80wt% when sintered at 1240°C for 3h.

Structural Evolution and Microwave Dielectric Properties of Ba(Co1/3(Nb1-xW5x/6)2/3)O3 Ceramics

2018 ◽  
Vol 281 ◽  
pp. 585-590
Author(s):  
Zhe Fei Wang ◽  
Chen Yao Zhai ◽  
Xu Hong Wang
Keyword(s):  
Dielectric Properties ◽  
Sintering Temperature ◽  
Structural Evolution ◽  
Microwave Dielectric Properties ◽  
Solid State Reaction Method ◽  
Second Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Microwave Dielectric ◽  
Dielectric Ceramics

Ba(Co1/3(Nb1-xW5x/6)2/3)O3 (0<x≤0.05) (BCWN) microwave dielectric ceramics have been prepared by solid-state reaction method. The microstructure and microwave dielectric properties of BCWN ceramics were investigated systematically in this paper. The results show that the sintering temperature decreases with the substitution of W6+. The Ba(Co1/3(Nb1-xW5x/6)2/3)O3 solid solution is formed with the small substitution of W6+ (x≤0.01). With the increase of x, the impurity phase BaWO4 occurrs and the grains become less homogeneous. Combined with the analysis of X-Ray Diffraction, the cation ordering degree on B-site increases in the sample of x=0.01, which leads to the decrease of the dielectric loss. However, the second phase BaWO4 inhibits the formation of the ordered structure with the reduction of sinterability. Due to the formation of BaWO4, the values of εr and τf of all samples decrease subsequently. The optimized microwave dielectric properties of Ba(Co1/3(Nb1-xW5x/6)2/3)O3 ceramics were obtained in the samples of x=0.01: εr=33.8, Q×f =110761 GHz, τf = -17 ppm/°C.

scholarly journals Sintering Behavior and Microwave Dielectric Properties of MgO-2B 2 O 3 - Xwt %H 3 BO 3 - Ywt %BCB Ceramics

2021 ◽  
Author(s):  
Haiquan WANG ◽  
Shixuan LI ◽  
Kangguo WANG ◽  
Huanfu ZHOU ◽  
Xiuli Chen
Keyword(s):  
Dielectric Properties ◽  
Bulk Density ◽  
Single Phase ◽  
Sintering Temperature ◽  
Microstructural Analysis ◽  
Microwave Dielectric Properties ◽  
Solid State Reaction Method ◽  
Sintering Behavior ◽  
X Ray Diffraction ◽  
Microwave Dielectric

Abstract The bulk density, sintering behavior and microwave dielectric properties of MgO-2B2O3 series ceramics synthesized by solid-state reaction method were systematically studied in this paper. X-ray diffraction and microstructural analysis revealed that the as-prepared MgO-2B2O3 ceramics possessed a single-phase structure with rod-like morphology. Through the investigation of the effects of different dosages of H3BO3 and BCB on bulk density, sintering behavior and microwave dielectric properties of MgO-2B2O3 ceramics, the optimum sintering temperature was obtained at an addition of 30wt%H3BO3 and 8wt%BCB and the sintering temperature was reduced to 825 oC. The addition of 40wt %H3BO3 and 4 wt%BCB increased the quality factor Q×f, permittivity εr and temperature coefficient of resonance frequency τf of MgO-2B2O3 to 44,306 GHz, 5.1 and -32 ppm/oC, respectively, meeting the criteria of low-temperature co-fired ceramics.

Structure and Microwave Dielectric Properties of (Ca0.9375Sr0.0625)0.25 (Li0.5Sm0.5)0.75TiO3 Ceramics with B2O3-CuO Sintering Aids

2011 ◽  
Vol 284-286 ◽  
pp. 1442-1446
Author(s):  
Yue Ming Li ◽  
Zong Yang Shen ◽  
Zhu Mei Wang ◽  
Hua Zhang ◽  
Yan Hong ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Dielectric Properties ◽  
Sintering Temperature ◽  
Microwave Dielectric Properties ◽  
Microwave Dielectric Ceramics ◽  
Sintering Aids ◽  
Oxide Mixture ◽  
High Permittivity ◽  
Microwave Dielectric ◽  
Dielectric Ceramics

The B2O3-CuO oxide mixture (abbreviated as BC) was selected to lower the sintering temperature of (Ca0.9375Sr0.0625)0.25(Li0.5Sm0.5)0.75TiO3 (abbreviated as CSLST) microwave dielectric ceramics by solid sate reaction technique. The effects of BC doping amounts on the crystal structure, microstructure and microwave dielectric properties of the ceramics were investigated. For the ceramic sample with the composition of CSLST + 5 wt% BC, its sintering temperature was reduced to 1000 °C as compared to 1200 °C for pure CSLST. In addition to the obtained good microwave dielectric properties as follows: εr = 80.4, Q×f = 1380 GHz, τf = -32.89 ×10-6/°C, this ceramic was a desirable high-permittivity microwave dielectric candidate for low-temperature cofired ceramic (LTCC) applications.

Influences of MnCO3 Doping on Processing Parameters and Dielectric Properties of ZnNb2O6 Microwave Ceramics

2007 ◽  
Vol 280-283 ◽  
pp. 23-26
Author(s):  
J. Luo ◽  
Z.Y. Pang ◽  
Y.S. Lin ◽  
Zhao Xian Xiong
Keyword(s):  
Dielectric Properties ◽  
Ceramic Body ◽  
Microwave Dielectric Properties ◽  
Microwave Frequency ◽  
Solid State Reaction Method ◽  
Processing Parameters ◽  
Microwave Ceramics ◽  
Conventional Solid State Reaction ◽  
Microwave Dielectric ◽  
Ceramic Microstructure

MnCO3 was added into ZnNb2O6 ceramics to obtain excellent microwave dielectric properties. The samples were prepared by conventional solid-state reaction method. The effects of the amount of MnCO3 on sintering temperatures, ceramic densities and contraction were systematically investigated. The crystalline structure of ceramic body was analyzed by XRD. The ceramic microstructure was observed by SEM. The dielectric properties of ZnNb2O6 ceramics were measured by a vector network analyzer at microwave frequency, which showed: er = 22.65, Q×f = 36700 GHz (loaded value) and tf = -40 ppm/°C.

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