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1.
Jian-Xi Tong Qi-Long Zhang Hui Yang Jia-Li Zou 《Journal of the American Ceramic Society》2007,90(3):845-849
The effects of LiF and ZnO–B2 O3 –SiO2 (ZBS) glass combined additives on phase composition, microstructures, and microwave dielectric properties of Ca[(Li1/3 Nb2/3 )0.84 Ti0.16 ]O3−δ (CLNT) ceramics were investigated. The LiF and ZBS glass combined additives lowered the sintering temperature of CLNT ceramics effectively from 1150° to 880°C. The main diffraction peaks of all the specimens split due to the coexistence of the non-stoichiometric phase (A) and stoichiometric phase (B), which all possess CaTiO3 -type perovskite structures. The transformation from A into B became accelerated with the increase of LiF or ZBS content. ZBS glass restrained the volatilization of lithium salt, which greatly affected the microstructures and microwave dielectric properties. CLNT ceramics with 2 wt% LiF and 3 wt% ZBS sintered at 900°C for 2 h show excellent dielectric properties: ɛr =34.3, Q × f =17 400 GHz, and τf =−4.6 ppm/°C. It is compatible with Ag electrodes, which makes it a promising ceramic for low-temperature cofired ceramics technology application. 相似文献
2.
A type of new low sintering temperature ceramic, Li2 TiO3 ceramic, has been found. Although it is difficult for the Li2 TiO3 compound to be sintered compactly at temperatures above 1000°C for the volatilization of Li2 O, dense Li2 TiO3 ceramics were obtained by conventional solid-state reaction method at the sintering temperature of 900°C with the addition of ZnO–B2 O3 frit. The sintering behavior and microwave dielectric properties of Li2 TiO3 ceramics with less ZnO–B2 O3 frit (≤3.0 wt%) doping were investigated. The addition of ZnO–B2 O3 frit can lower the sintering temperature of the Li2 TiO3 ceramics, but it does not apparently degrade the microwave dielectric properties of the Li2 TiO3 ceramics. Typically, the good microwave dielectric properties of ɛr =23.06, Q × f =32 275 GHz, τf = 35.79 ppm/°C were obtained for 2.5 wt% ZnO–B2 O3 frit-doped Li2 TiO3 ceramics sintered at 900°C for 2 h. The porosity was 0.08%. The Li2 TiO3 ceramic system may be a promising candidate for low-temperature cofired ceramics applications. 相似文献
3.
The effect of the addition of V2 O5 on the structure, sintering and dielectric properties of M -phase (Li1+ x − y Nb1− x −3 y Ti x +4 y )O3 ceramics has been investigated. Homogeneous substitution of V5+ for Nb5+ was obtained in LiNb0.6(1− x ) V0.6 x Ti0.5 O3 for x ≤ 0.02. The addition of V2 O5 led to a large reduction in the sintering temperature and samples with x = 0.02 could be fully densified at 900°C. The substitution of vanadia had a relatively minor adverse effect on the microwave dielectric properties of the M -phase system and the x = 0.02 ceramics had [alt epsilon]r = 66, Q × f = 3800 at 5.6 GHz, and τf = 11 ppm/°C. Preliminary investigations suggest that silver metallization does not diffuse into the V2 O5 -doped M -phase ceramics at 900°C, making these materials potential candidates for low-temperature cofired ceramic (LTCC) applications. 相似文献
4.
Hyo Tae Kim Myoung-Hwa Nam Jong-Hee Kim Sahn Nahm 《International Journal of Applied Ceramic Technology》2009,6(5):587-592
Dolomite-type borate ceramics consisting of CaZrB2 O6 were synthesized via a conventional solid-state reaction route; low-temperature sintering was explored using Bi2 O3 –CuO additives of 1–7 wt% for low-temperature co-fired ceramics applications. For several sintering temperatures, the microwave dielectric properties and chemical resistance of the ceramics were investigated. The CaZrB2 O6 ceramics with 3 wt% Bi2 O3 –CuO addition could be sintered below 925°C, and the microwave dielectric properties of the low-temperature samples were ɛr =10.55, Q × f =87,350 GHz, and τf =+2 ppm/°C. The chemical resistance test result showed that both CaZrB2 O6 - and Bi2 O3 –CuO-added CaZrB2 O6 ceramics were durable in basic solution but were degraded in acid solution. 相似文献
5.
Synthesis of BaCu(B2 O5 ) Ceramics and their Effect on the Sintering Temperature and Microwave Dielectric Properties of Ba(Zn1/3 Nb2/3 )O3 Ceramics 总被引:1,自引:0,他引:1
Min-Han Kim Jong-Bong Lim Jae-Chul Kim Sahn Nahm Jong-Hoo Paik Jong-Hee Kim Kyeong-Soon Park 《Journal of the American Ceramic Society》2006,89(10):3124-3128
BaCu(B2 O5 ) ceramics were synthesized and their microwave dielectric properties were investigated. BaCu(B2 O5 ) phase was formed at 700°C and melted above 850°C. The BaCu(B2 O5 ) ceramic sintered at 810°C had a dielectric constant (ɛr ) of 7.4, a quality factor ( Q × f ) of 50 000 GHz and a temperature coefficient of resonance frequency (τf ) of −32 ppm/°C. As the BaCu(B2 O5 ) ceramic had a low melting temperature and good microwave dielectric properties, it can be used as a low-temperature sintering aid for microwave dielectric materials for low temperature co-fired ceramic application. When BaCu(B2 O5 ) was added to the Ba(Zn1/3 Nb2/3 )O3 (BZN) ceramic, BZN ceramics were well sintered even at 850°C. BaCu(B2 O5 ) existed as a liquid phase during the sintering and assisted the densification of the BZN ceramic. Good microwave dielectric properties of Q × f =16 000 GHz, ɛr =35, and τf =22.1 ppm/°C were obtained for the BZN+6.0 mol% BaCu(B2 O5 ) ceramic sintered at 875°C for 2 h. 相似文献
6.
Jin-Seong Kim Ngoc-Huan Nguyen Jong-Bong Lim Dong-Soo Paik Sahn Nahm Jong-Hoo Paik Jong-Hee Kim Hwack-Joo Lee 《Journal of the American Ceramic Society》2008,91(2):671-674
B2 O3 was added to nominal composition Zn1.8 SiO3.8 (ZS) ceramics to decrease their sintering temperature for application to low-temperature cofired ceramic (LTCC) devices. B2 O3 reacted with SiO2 to form a liquid phase containing SiO2 and B2 O3 . The composition and melting temperature of the liquid phase depended on the sintering temperature and the B2 O3 content. The specimen containing 20.0 mol% of B2 O3 sintered at 900°C exhibited high microwave dielectric properties of Q × f =53 000 GHz, ɛ r =5.7, and τf =−16 ppm/°C, confirming the promising potential of the B2 O3 -added ZS ceramics as candidate materials for the LTCC devices. 相似文献
7.
Takahiro Takada Sea Fue Wang Shoko Yoshikawa Sei-Joo Jang Robert E. Newnham 《Journal of the American Ceramic Society》1994,77(7):1909-1916
The effect of glass addition on the properties of BaO–TiO2 -WO3 microwave dielectric material N-35, which has Q = 5900 and K = 35 at 7.2 GHz for samples sintered at 1360°C, was investigated. Several glasses including B2 O3 , SiO2 , 5ZnO–2B2 O3 , and nine other commercial glasses were selected for this study. Among these glasses, one with a 5 wt% addition of B2 O3 to N-35, when sintered at 1200°C, had the best dielectric properties: Q = 8300 and K = 34 at 8.5 GHz. Both Q and K increased with firing temperature as well as with density. The Q of N-35, when sintered with a ZnO–B2 O3 glass system, showed a sudden drop in the sintering temperature to about 1000°C. The results of XRD, thermal analysis, and scanning electron microscopy indicated that the chemical reaction between the dielectric ceramics and glass had a greater effect on Q than on the density. The effects of the glass content and the mixing process on the densification and microwave dielectric properties are also presented. Ball milling improved the densification and dielectric properties of the N-35 sintered with ZnO–B2 O3 . 相似文献
8.
Qun Zeng Wei Li Jian-lin Shi Xian-lin Dong Jing-kun Guo 《Journal of the American Ceramic Society》2007,90(7):2262-2265
The effects of the addition of V2 O5 on the sintering behavior, microstructure, and microwave dielectric properties of 5Li2 O–1Nb2 O5 –5TiO2 (LNT) ceramics have been investigated. With low-level doping of V2 O5 (≤3 wt%), the microstructure of the LNT ceramic changed from a special two-level intergrowth structure into a two-phase composite structure with separate grains. And the sintering temperature of the LNT ceramics could be lowered to around 900°C by adding a small amount of V2 O5 without much degradation in microwave dielectric properties. Typically, better microwave dielectric properties of ɛr =41.7, Q × f =7820 GHz, and τ f =45 ppm/°C could be obtained for the 1 wt% V2 O5 -doped ceramics sintered at 900°C. 相似文献
9.
Sea-Fue Wang Chiang-Chuang Chung Chai-Hui Wang Jinn P. Chu 《Journal of the American Ceramic Society》2002,85(6):1619-1621
Preparation of dense and phase-pure Ba2 Ti9 O20 is generally difficult using solid-state reaction, since there are several thermodynamically stable compounds in the vicinity of the desired composition and a curvature of Ba2 Ti9 O20 equilibrium phase boundary in the BaO–TiO2 system at high temperatures. In this study, the effects of B2 O3 on the densification, microstructural evolution, and phase stability of Ba2 Ti9 O20 were investigated. It was found that the densification of Ba2 Ti9 O20 sintered with B2 O3 was promoted by the transient liquid phase formed at 840°C. At sintering temperatures higher than 1100°C, the solid-state sintering became dominant because of the evaporation of B2 O3 . With the addition of 5 wt% B2 O3 , the ceramic yielded a pure Ba2 Ti9 O20 phase at sintering temperatures as low as 900°C, without any solid solution additive such as SnO2 or ZrO2 . The facilities of B2 O3 addition to the stability of Ba2 Ti9 O20 are apparently due to the eutectic liquid phase which accelerates the migration of reactant species. 相似文献
10.
Qun Zeng Wei Li Jian-lin Shi Jing-kun Guo 《Journal of the American Ceramic Society》2006,89(10):3305-3307
The effects of V2 O5 addition on the sintering behavior, microstructure, and the microwave dielectric properties of 5Li2 O–0.583Nb2 O5 –3.248TiO2 (LNT) ceramics have been investigated. With addition of low-level doping of V2 O5 (≤2 wt%), the sintering temperature of the LNT ceramics could be lowered down to around 920°C due to the liquid phase effect. A secondary phase was observed at the level of 2 wt% V2 O5 addition. The addition of V2 O5 does not induce much degradation in the microwave dielectric properties but lowers the τf value to near zero. Typically, the excellent microwave dielectric properties of ɛr =21.5, Q × f =32 938 GHz, and τf =6.1 ppm/°C could be obtained for the 1 wt% V2 O5 -doped sample sintered at 920°C, which is promising for application of the multilayer microwave devices using Ag as an internal electrode. 相似文献
11.
Jin-Seong Kim Ngoc-Huan Nguyen Myung-Eun Song Jong-Bong Lim Dong-Soo Paik Sahn Nahm Jong-Hoo Paik Byung-Hyun Choi Soon-Jae Yu 《International Journal of Applied Ceramic Technology》2009,6(5):581-586
Bi2 O3 was added to a nominal composition of Zn1.8 SiO3.8 (ZS) ceramics to decrease their sintering temperature. When the Bi2 O3 content was <8.0 mol%, a porous microstructure with Bi4 (SiO4 )3 and SiO2 second phases was developed in the specimen sintered at 885°C. However, when the Bi2 O3 content exceeded 8.0 mol%, a liquid phase, which formed during sintering at temperatures below 900°C, assisted the densification of the ZS ceramics. Good microwave dielectric properties of Q × f =12,600 GHz, ɛr =7.6, and τf =−22 ppm/°C were obtained from the specimen with 8.0 mol% Bi2 O3 sintered at 885°C for 2 h. 相似文献
12.
Sung Min Rhim Seokmin Hong Heungjin Bak Ok Kyung Kim 《Journal of the American Ceramic Society》2000,83(5):1145-1148
The effects of B2 O3 addition on the sintering behavior and the dielectric and ferroelectric properties of Ba0.7 Sr0.3 TiO3 (BST) ceramics were investigated. The dielectric and ferroelectric properties of a BST sample with 0.5 wt% B2 O3 sintered at <1150°C were as good as those of undoped BST sintered at 1350°C, and the dielectric loss was better. When >1.0 wt% B2 O3 was added to BST, the overdoped B2 O3 did not form a liquid phase or volatilize; it remained in the samples and formed a secondary phase that lowered the sintering behavior and the dielectric and ferroelectric properties of the BST. 相似文献
13.
Masahide Okamoto Hironori Kodama Kazuo Shinozaki 《Journal of the American Ceramic Society》2008,91(4):1110-1114
The sintering of a composite of MgO–B2 O3 –Al2 O3 glass and Al2 O3 filler is terminated due to the crystallization of Al4 B2 O9 in the glass. The densification of a composite of MgO–B2 O3 –Al2 O3 glass and Al2 O3 filler using pressureless sintering was accomplished by lowering the sintering temperature of the composite. The sintering temperature was lowered by the addition of small amounts of alkali metal oxides to the MgO–B2 O3 –Al2 O3 glass system. The resultant composite has a four-point bending strength of 280 MPa, a coefficient of thermal expansion (RT—200°C) of 4.4 × 10−6 K−1 , a dielectric constant of 6.0 at 1 MHz, porosity of approximately 1%, and moisture resistance. 相似文献
14.
Dong-Wan Kim Jeong-Ryeol Kim Sung-Hun Yoon Kug Sun Hong Chang Kyung Kim 《Journal of the American Ceramic Society》2002,85(11):2759-2762
The effect of B2 O3 on the sintering temperature and microwave dielectric properties of Ba5 Nb4 O15 has been investigated using X-ray powder diffraction, scanning electron microscopy, and a network analyzer. Interactions between Ba5 Nb4 O15 and B2 O3 led to formation of second phases, BaNb2 O6 and BaB2 O4 . The addition of B2 O3 to Ba5 Nb4 O15 resulted in lowering the sintering temperature from 1400° to 925°C. Low-fired Ba5 Nb4 O15 could be interpreted by measuring changes in the quality factor ( Q × f ), the relative dielectric constant (ɛr ), and the temperature coefficient of resonant frequency (τf ) as a function of B2 O3 additions. More importantly, the formation of BaNb2 O6 provided temperature compensation. The microwave dielectric properties of low-fired Ba5 Nb4 O15 had good dielectric properties: Q × f = 18700 GHz, ɛr = 39, and τf = 0 ppm/°C. 相似文献
15.
Yaping Zhang Yunxia Yang Yuwen Ou Wei Hua Jiahua Zheng Guorong Chen 《Journal of the American Ceramic Society》2009,92(8):1881-1883
Glasses with compositions 50Bi2 O3 – x Sb2 O3 –10B2 O3 –(40– x ) SiO2 ( x =0, 1, 3, 5, 8, 10) have been prepared by conventional melt quench technique. Substitution of Sb2 O3 for SiO2 exerted an obvious effect on properties of glasses, especially, increased glass transition temperature ( T g ) and crystalline temperature ( T c ) greatly. Results of infrared transmission spectra attributed the effect to the formation of new bridging bonds of Sb–O–B and Sb–O–Si in glass network. 相似文献
16.
Beata Zalinska Mehdi Mirsaneh Ian M. Reaney 《Journal of the American Ceramic Society》2009,92(9):1981-1985
The effect of a bespoke glass sintering aid, 0.3Bi2 O3 –0.3Nb2 O5 –0.3B2 O3 –0.1SiO2 (BN1), developed from the base ceramic composition, BiNbO4 (BN), on the sinterability, microstructure, and microwave (MW) dielectric properties of BN ceramics has been investigated. Densities >97% theoretical could be achieved at 1020°C for samples with up to 15% BN1 additions. The resulting microstructure was composed of BN laths surrounded by a residual glass phase that contained small fibrous crystals. Some evidence of dissolution of BN crystals was observed. Optimum properties were exhibited for samples with 15 wt% of glass addition sintered for 4 h at 1020°C with a relative permittivity ɛr =38, a MW quality factor Q × f 0 =17 353 at 5.6 GHz, and a temperature coefficient of resonant frequency τf =−10 ppm/°C. The high Q × f 0 , ɛr , and low τf , coupled with a relatively low sintering temperature, suggest that the use of bespoke glass sintering aids of this type may have great potential for the fabrication of MW ceramics. 相似文献
17.
Mukkuttiparambil Ayyappan Sanoj Chalappurath Pattelath Reshmi Manoj Raama Varma 《Journal of the American Ceramic Society》2009,92(11):2648-2653
ZnNb2 O6 (ZN) is a columbite-structured niobate compound showing excellent dielectric properties and comparatively low sintering temperatures (∼1200°C). Hence it is a good candidate for possible low-temperature cofired ceramics (LTCC) applications. In the present investigation, ZnNb2 O6 was synthesized in the form of micrometer-sized powder using a conventional solid-state ceramic synthesis route as well as in the form of nanosized powder by a polymer complex method. The finite size effect of ZN particles on sinterability and microwave dielectric properties of sintered pellets was evaluated. The phase formation was confirmed from the X-ray diffraction (XRD) analysis. The particle size distribution of the nanoparticles was found to be of the order of 18–20 nm by using high-resolution transmission electron microscopy analysis and 30 nm by analyzing the XRD patterns using Debye Scherrer's formula, after correcting for the instrument broadening effects. A ZN–60ZnO–30B2 O3 –10SiO2 (ZBS) composite was made by adding predetermined amounts of glasses. The microstructures of the sintered pellets of ZN and ZN–ZBS composites were examined using scanning electron microscopy and analyzed using image analysis. The nano-ZN–ZBS composites were sintered to 93% of the reported density at 925°C/2 h, with microwave dielectric properties of ɛr =22.5, Q × f ∼12 800 GHz, and τf =−69.6 ppm/°C, emerging as a potential material for possible LTCC applications. 相似文献
18.
The electrical properties of Sr0.5 Ba0.3 TiO3 in the presence of Nb2 O5 as a donor, 3Li2 O · 2SiO2 as a sintering agent, and Bi2 O3 as a dopant have been studied. When the compositions of the ceramics were 1 mol Sr0.7 Ba0.3 TiO3 + 0.5 mol% Nb2 O5 + 2 mol% 3Li2 O · 2SiO2 + 0.2 mol% Bi2 O3 , the ceramics were sintered at 1100°C and exhibited the following characteristics: apparent dielectric constant ɛ, 25000; loss factor tan δ, 2%; insulating resistivity ρj , 1010 Ω· cm; variation of dielectric constant with temperature Δɛ/ɛ (−25° to +85°C), +10%, −14%. ɛ and tan δ show only small changes with frequency. The study shows this ceramic can be used in multilayer technology. 相似文献
19.
Cristina Siligardi Luca Lusvarghi Monia Montorsi Cecilia Vernia 《Journal of the American Ceramic Society》2008,91(3):990-995
In this work several complementary techniques have been employed to carefully characterize the sintering and crystallization behavior of CaO–Al2 O3 –ZrO2 –SiO2 glass powder compacts after different heat treatments. The research started from a new base glass 33.69 CaO–1.00 Al2 O3 –7.68 ZrO2 –55.43SiO2 (mol%) to which 5 and 10 mol% Al2 O3 were added. The glasses with higher amounts of alumina sintered at higher temperatures (953°C [lower amount] vs. 987°C [higher amount]). A combination of the linear shrinkage and viscosity data allowed to easily find the viscosity values corresponding to the beginning and the end of the sintering process. Anorthite and wollastonite crystals formed in the sintered samples, especially at lower temperatures. At higher temperatures, a new crystalline phase containing ZrO2 (2CaO·4SiO2 ·ZrO2 ) appeared in all studied specimens. 相似文献
20.
Yang Gong-An Pu Yong-Ping Wang Jin-Fei Chen Xiao-Long Zhuang Yong-Yong 《Journal of the American Ceramic Society》2009,92(8):1891-1894
The influence of La2 O3 doped on the microstructure and dielectric properties, including the phase structure, temperature dependence of permittivity, and the hysteresis loop of BaTiO3 –Nb2 O5 –Fe2 O3 (BTNF) materials has been investigated in X-ray diffraction, SEM, and LCR analyzer, respectively. Experiments revealed that incorporation of proper content of La2 O3 basically soluted in the lattice of BaTiO3 and can control the grain-growth, reduce the dielectric loss of the BTNF materials. The development of microstructure promoted by the additives can result in the improvement of the dielectric constant. When the doping concentration of La2 O3 was 3.846 wt%, the relative dielectric constant of the sample sintered at 1280°C only for 2 h could reach 4308, and improve the dielectric-temperature characteristics markedly. As a result, a novel Y5P can be achieved in the BTNF ceramics, which is very promising for practical use in Y5P multilayer ceramic capacitors. 相似文献