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1.
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
2.
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
3.
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
4.
Yanping Long Yilin Wang Wenjun Wu Dong Wang Yongxiang Li 《Journal of the American Ceramic Society》2009,92(11):2630-2633
The effect of B2 O3 –SiO2 liquid-phase additives on the sintering, microstructure, and microwave dielectric properties of LiNb0.63 Ti0.4625 O3 ceramics was investigated. It was found that the sintering temperature could be lowered easily, and the densification and dielectric properties of LiNb0.63 Ti0.4625 O3 ceramics could be greatly improved by adding a small amount of B2 O3 –SiO2 solution additives. No secondary phase was observed for the ceramics with B2 O3 –SiO2 additives. With the addition of 0.10 wt% B2 O3 –SiO2 , the ceramics sintered at 900°C showed favorable microwave dielectric properties with ɛr =71.7, Q × f =4950 GHz, and τf =−2.1 ppm/°C. The energy dispersive spectra analysis showed an excellent co-firing interfacial behavior between the LiNb0.63 Ti0.4625 O3 ceramic and the Ag electrode. It indicated that LiNb0.63 Ti0.4625 O3 ceramics with B2 O3 –SiO2 solution additives have a number of potential applications on passive integrated devices based on the low-temperature co-fired ceramics technology. 相似文献
5.
Jae Chul Kim Min-Han Kim Jong-Bong Lim Sahn Nahm Jong-Hoo Paik Jong-Hee Kim 《Journal of the American Ceramic Society》2007,90(2):641-644
Re3 Ga5 O12 (Re: Nd, Sm, Eu, Dy, Yb, and Y) garnet ceramics were synthesized and their microwave dielectric properties were investigated for advanced substrate materials in microwave integrated circuits. The Re3 Ga5 O12 ceramics sintered at 1350°–1500°C had a high-quality factor ( Q × f ) ranging from 40 000 to 192 173 GHz and a low-dielectric constant (ɛr ) of between 11.5 and 12.5. They also exhibited a relatively stable temperature coefficient of resonant frequency (τf ) in the range of −33.7 to −12.4 ppm/°C. In particular, the Sm3 Ga5 O12 ceramics sintered at 1450°C exhibited good microwave dielectric properties of ɛr =12.4, Q × f =192 173 GHz, and τf =−19.2 ppm/°C. 相似文献
6.
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
7.
The BiVO4 additive was found effective for low-temperature firing of ZnNb2 O6 polycrystalline ceramics below 950°C in air without a serious degradation in their microwave dielectric properties. Dense BiVO4 -doped ZnNb2 O6 samples of a relative sintered density over 95% could be prepared even at 925°C. An optimally processed specimen exhibited excellent microwave dielectric properties of Q · f = 55000 GHz, ɛr = 26, and τf =−57 ppm/°C. With increasing BiVO4 addition up to 20 mol% relative to ZnNb2 O6 , while the quality factor Q · f was gradually decreased, the relative dielectric constant, ɛr , was linearly increased and the temperature coefficient of resonant frequency, τf , was slightly increased. The variations in Q · f and ɛr are surely attributable to the residual BiVO4 in the ZnNb2 O6 matrix. An unexpected slight increase in τf is probably due to the formation of the Bi(V,Nb)O4 -type solid solution. 相似文献
8.
Rejini Rajamma Mailadil Thomas Sebastian 《Journal of the American Ceramic Society》2007,90(8):2472-2475
The microwave dielectric properties of two A-site-deficient perovskite-type ceramics in the La6 Mg4 A2 W2 O24 [A=Ta and Nb] system were investigated. The compounds were synthesized by the solid-state ceramic route. The structure and microstructure were analyzed using X-ray diffraction and scanning electron microscopy techniques. The dielectric properties were measured in the microwave frequency range [4–6 GHz] by the resonance method. La6 Mg4 Ta2 W2 O24 had Q u × f =13 600 GHz, ɛr =25.2, and τf =−45 ppm/°C and La6 Mg4 Nb2 W2 O24 had Q u × f =16 400 GHz, ɛr =25.8, and τf =−56 ppm/°C. 相似文献
9.
Ching-Fang Tseng Cheng-Liang Huang Cheng-Hsing Hsu 《Journal of the American Ceramic Society》2007,90(5):1619-1622
The microwave dielectric properties and the microstructures of Nd(Co1/2 Ti1/2 )O3 (NCT) ceramics using starting powders of Nd2 O3 , CoO, and TiO2 prepared by the conventional solid-state route have been researched. The dielectric constant values (ɛr ) saturated at 24.8–27. Quality factor ( Q × f ) values of 37 900–140 000 (at 9 GHz) and the measured τf values ranging from −45 to −48 ppm/°C can be obtained when the sintering temperatures are in the range of 1410°–1500°C. The ɛr value of 27, the Q × f value of 140 000 (at 9 GHz) and the τf value of −46 ppm/°C were obtained for NCT ceramics sintered at 1440°C for 4 h. For applications of high selective microwave ceramic resonator, filter, and antenna, NCT is proposed as a suitable material candidate. 相似文献
10.
A Zn2 Te3 O8 ceramic was investigated as a promising dielectric material for low-temperature co-fired ceramics (LTCC) applications. The Zn2 Te3 O8 ceramic was synthesized using the solid-state reaction method by sintering in the temperature range 540°–600°C. The structure and microstructure of the compounds were investigated using X-ray diffraction (XRD) and scanning electron microscopy methods. The dielectric properties of the ceramics were studied in the frequency range 4–6 GHz. The Zn2 Te3 O8 ceramic has a dielectric constant (ɛr ) of 16.2, a quality factor ( Q u × f ) of 66 000 at 4.97 GHz, and a temperature coefficient of resonant frequency (τf ) of −60 ppm/°C, respectively. Addition of 4 wt% TiO2 improved the τf to −8.7 ppm/°C with an ɛr of 19.3 and a Q u × f of 27 000 at 5.14 GHz when sintered at 650°C. The chemical reactivity of the Zn2 Te3 O8 ceramic with Ag and Al metal electrodes was also investigated. 相似文献
11.
Lamrath Abdul Khalam Sherin Thomas Mailadil T. Sebastian 《International Journal of Applied Ceramic Technology》2007,4(4):359-366
The columbites MgNb2 O6 , MgTa2 O6 , and corundum-type Mg4 Nb2 O9 ceramics were prepared by the conventional solid-state ceramic route. The structure and microstructure of the sintered samples were investigated by X-ray diffraction and scanning electron microscopic techniques. The microwave dielectric properties of the samples were measured by the resonance method in the frequency range 4–6 GHz. The dielectric properties have been tailored by forming a solid solution between MgNb2 O6 and MgTa2 O6 and by the substitution of TiO2 for Nb2 O5 in both MgNb2 O6 and Mg4 Nb2 O9 ceramics. The Mg(Nb0.7 Ta1.3 )O6 has ɛr =29, Q u × f =67 800 GHz, and τf =0.8 ppm/°C and the MgO–(0.4)Nb2 O5 –(1.5)TiO2 composition has ɛr =34.5, Q u × f =81 300 GHz, and τf =−2 ppm/°C. 相似文献
12.
A new ultra low loss microwave dielectric ceramic, Mg(Sn0.05 Ti0.95 )O3 (MSnT), was found and investigated. The compounds were prepared by the conventional solid-state route, and sintered at 1360°–1480°C for 2–6 h. The investigations show that the MgTi2 O5 secondary phase was observed. Moreover, the dielectric properties were correlated with the formation second phase. The excellent microwave dielectric properties of Q × f =322 000 (GHz), ɛr =17.4, and τf =−54 ppm/°C were obtained from the new MSnT ceramics sintered at 1390°C for 4 h. 相似文献
13.
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
14.
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
15.
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
16.
Ching-Fang Tseng Cheng-Liang Huang Wen-Ruei Yang Cheng-Hsing Hsu 《Journal of the American Ceramic Society》2006,89(4):1465-1470
The microwave dielectric properties and the microstructures of Nd(Zn1/2 Ti1/2 )O3 (NZT) ceramics prepared by the conventional solid-state route have been studied. The prepared NZT exhibited a mixture of Zn and Ti showing 1:1 order in the B-site. The dielectric constant values (ɛr ) saturated at 29.1–31.6. The quality factor ( Q × f ) values of 56 700–170 000 (at 8.5 GHz) can be obtained when the sintering temperatures are in the range of 1300°–1420°C. The temperature coefficient of resonant frequency τf was not sensitive to the sintering temperature. The ɛ r value of 31.6, the Q × f value of 170 000 (at 8.5 GHz), and the τf value of −42 ppm/°C were obtained for NZT ceramics sintering at 1330°C for 4 h. For applications of high selective microwave ceramic resonators, filters, and antennas, NZT is proposed as a suitable material candidate. 相似文献
17.
Hanxing Liu Hongtao Yu Zhongqing Tian Zhenghua Meng Zhaohui Wu Shixi Ouyang 《Journal of the American Ceramic Society》2005,88(2):453-455
The microwave dielectric properties of the (1− x )CaTiO3 – x Ca(Zn1/3 Nb2/3 )O3 ceramic system have been investigated. The ceramic samples sintered at 1300°–1450°C for 4 h in air exhibit orthorhombic pervoskite and form a complete solid solution for different x value. When the x value increased from 0.2 to 0.8, the permittivity ɛr decreased from 115 to 42, the unloaded quality factor Q × f increased from 5030 to 13 030 GHz, and the temperature coefficient τf decreased from 336 to −28 ppm/°C. When x =0.7, the best combination of dielectric properties, a near zero temperature coefficient of resonant frequency of τf ∼−6 ppm/°C, Q × f ∼10 860 GHz and ɛr ∼51 is obtained. 相似文献
18.
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
19.
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
20.
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