Microwave dielectric properties of (1 − x)Cu3Nb2O8−xZn3Nb2O8 ceramics

2001 ◽  
Vol 16 (5) ◽  
pp. 1465-1470 ◽  
Author(s):  
Dong-Wan Kim ◽  
In-Tae Kim ◽  
Byungwoo Park ◽  
Kug Sun Hong ◽  
Jong-Hee Kim
Keyword(s):  
Solid Solution ◽  
Dielectric Properties ◽  
Microwave Dielectric Properties ◽  
Sintering Behavior ◽  
X Ray Diffraction ◽  
Two Phase ◽  
Sintering Aid ◽  
Microwave Dielectric ◽  
Solid Solution Region ◽  
Solution Region

The sintering behavior and microwave dielectric properties of (1 − x)Cu3Nb2O8−xZn3Nb2O8 have been investigated using dilatometry, x-ray diffraction, and a network analyzer. It was found that (1 − x)Cu3Nb2O8−xZn3Nb2O8 ceramics have a much lower melting temperature than Zn3Nb2O8 ceramics without Cu3Nb2O8 additives. Samples sintered at 900 °C for 2 h exhibited densities >97% of the theoretical density. Cu3Nb2O8 acts as a sintering aid. Two phase regions were identified with increasing Zn3Nb2O8 contents. A Cu3Nb2O8−Zn3Nb2O8 solid solution exists from 0 < x < 0.5 while a mixture of Cu3Nb2O8 and Zn3Nb2O8 exists from 0.5 < x < 1. The microwave dielectric properties correlated to the crystal structure. In Cu3Nb2O8−Zn3Nb2O8 solid solution region, the variation of dielectric properties could be explained by the structure distortion of Cu3Nb2O8 due to electronic anisotropies of Cu2+ cations.

Phase Relations and Microwave Dielectric Properties of ZnNb2O6–TiO2

2000 ◽  
Vol 15 (6) ◽  
pp. 1331-1335 ◽  
Author(s):  
Dong-Wan Kim ◽  
Deok-Yang Kim ◽  
Kug Sun Hong
Keyword(s):  
Solid Solution ◽  
Dielectric Properties ◽  
Quality Factor ◽  
Microwave Dielectric Properties ◽  
Relative Dielectric Constant ◽  
Phase Relations ◽  
Rutile Structure ◽  
Microwave Dielectric ◽  
Solid Solution Region ◽  
Solution Region

The phase relations and microwave dielectric properties of (1−x)ZnNb2O6–xTiO2 were investigated using x-ray powder diffraction and a network analyzer. Four phase regions were studied with increasing TiO2 mol% (x): columbite solid solution, ixiolite (ZnTiNb2O8) solid solution, mixture of ixiolite and rutile solid solutions, and rutile solid solution. It was suggested that the microwave properties depend on crystal structure rather than chemical composition. In the columbite solid solution region, an order–disorder transition was found with an increasing amount of TiO2, and the quality factor decreased sharply. ZnTiNb2O8 (x = 0.5), has a fully disordered structure and possesses a quality factor of 42,500, relative dielectric constant (εr) of 34.3, and temperature coefficient of resonant frequency (τf) of −52 ppm/°C. In the mixture region of ixiolite and rutile structure, τf was modified to around 0 ppm/°C.

Reaction Sintering of β-Si3N4/α'-Sialon Ceramics

1992 ◽  
Vol 287 ◽  
Author(s):  
S. Boskovic ◽  
K.J. Lee ◽  
T.Y. Tien
Keyword(s):  
Solid Solution ◽  
Applied Pressure ◽  
Phase Region ◽  
Reaction Sintering ◽  
Two Phase ◽  
Sintering Aid ◽  
Third Phase ◽  
Solid Solution Region ◽  
Tie Lines ◽  
Solution Region

ABSTRACTCompositions in the α'-SiAlON-√-Si3N4 solid solution region in the system Si,Al,Y/N,O which contained a third phase as a sintering aid were prepared. Mixtures of starting materials were reaction sintered to full densities without applied pressure. Phases were identified and lattice parameters of β' and √ph ases were measured and compared with standards. The results were used to construct β'-SiAION-√-Si3N4 solidsolution tie lines in the two phase region. As expected, the specimens with a higher β'-SiAION content showed higher hardness and lower toughness values.

Effect of H3BO3 Coating on the Microwave Dielectric Properties of BZN Ceramics

2014 ◽  
Vol 906 ◽  
pp. 8-11
Author(s):  
Liu Shuan Yang ◽  
Biao Jin ◽  
Xiao Wang
Keyword(s):  
Dielectric Properties ◽  
Ceramic Composite ◽  
Microwave Dielectric Properties ◽  
Sintering Behavior ◽  
Network Analyzer ◽  
X Ray Diffraction ◽  
Ceramic Specimen ◽  
Coating Technology ◽  
X Ray ◽  
Microwave Dielectric

(Bi1.5Zn0.5)(Zn0.5Nb1.5)O7(BZN) ceramic samples were prepared by solid state reaction. B2O3 was introduced by liquid coating technology with H3BO3 solution in the BZN ceramic specimen to reduce its sintering temperature. The sintering behavior, phase composition and dielectric properties of ceramics were investigated by X-ray diffraction, scanning electron microscopy and vector network analyzer. The (Bi1.5Zn0.5)(Zn0.5Nb1.5)O7 ceramic composite could be sintered well at 900°C for 3h when 0.9M/l H3BO3 was added and showed good dielectric properties of εr=150,Q×f=228,τf=-362ppm/°C.

A new microwave dielectric ceramics based on the solid solution system between Ba(Ni1/3Nb2/3)O3 and Ba(Zn1/3Nb2/3)O3

1997 ◽  
Vol 12 (6) ◽  
pp. 1558-1562 ◽  
Author(s):  
Seo-Yong Cho ◽  
Hyuk-Joon Youn ◽  
Kug-Sun Hong ◽  
In-Tae Kim ◽  
Yoon-Ho Kim
Keyword(s):  
Solid Solution ◽  
Dielectric Properties ◽  
Pechini Method ◽  
Microwave Dielectric Properties ◽  
Processing Parameters ◽  
X Ray Diffraction ◽  
Solution System ◽  
Microwave Dielectric ◽  
Solid Solution System ◽  
Dielectric Ceramics

Microwave dielectric properties of the solid solution between Ba(Ni1/3Nb2/3)O3 and Ba(Zn1/3Nb2/3)O3 were investigated. Samples were prepared by the conventional mixed oxide method as well as the Pechini method. Sintered samples were analyzed using x-ray diffraction and scanning electron microscopy, and their microwave dielectric properties were measured by the post resonator method. The sample prepared by the Pechini method revealed excellent dielectric properties, i.e., permittivity of 35.6, quality factor of 5700 at 10 GHz, and very small temperature coefficient of resonant frequency. Order-disorder behavior of this solid solution system was found to depend on processing parameters. Variation in microwave dielectric properties was discussed in terms of the order-disorder behavior, chemical composition, mixture rule, etc.

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.

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