共查询到20条相似文献,搜索用时 15 毫秒
1.
微波介质陶瓷的研究现状及展望 总被引:2,自引:0,他引:2
微波介质陶瓷是现代通讯技术中的关键基础材料,它的应用日益受到人们的重视。本文综述了四类微波介质陶瓷的研究现状,并对其未来的发展进行了展望。 相似文献
2.
微波介质陶瓷的研究进展 总被引:1,自引:0,他引:1
综述了微波介质陶瓷材料的特性和发展现状,给出了多数目前已经研究的微波陶瓷体系及其性能,阐述了其制备方法,提出了改善其性能的途径和微波介质陶瓷的预期进展. 相似文献
3.
Structure,Microwave Dielectric Properties,and Novel Low‐Temperature Sintering of xSrTiO3–(1−x)LaAlO3 Ceramics with LTCC Application
下载免费PDF全文
![点击此处可从《Journal of the American Ceramic Society》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Shenhui Lei Huiqing Fan Weina Chen Zhiyong Liu Mengmeng Li 《Journal of the American Ceramic Society》2017,100(1):235-246
xSrTiO3–(1?x)LaAlO3 ceramics with ZnO–B2O3 sintering aid were prepared by solid‐state reaction method leading to a significant decrease in sintering temperature from 1550°C to 1050°C. The structure, microwave dielectric properties, and low‐temperature sintering behavior were systematically investigated. The results revealed the relationships among ionic size, ionic polarizability and cell volume. With increasing additive, chemical ordering of B‐site cations was indicated with selected area electron diffraction (SAED) patterns, HRTEM images and Raman spectrum, which contributed to the greatly enhanced microwave dielectric properties. Particularly, the 0.7Sr0.85 Mg0.15TiO3–0.3LaAlO3 ceramics modified with 10 wt % ZnO‐B2O3 can further decrease the sintering temperature down to 950°C without deteriorating its performance. Thermal tests implied ceramics featured good chemical compatibility with Cu/Ag electrode. Thus, they can be cofired with internal Cu/Ag electrodes in special patterns to fulfill different electrical functions for LTCC (low‐temperature cofired ceramic) application. 相似文献
4.
采用固相反应法制备了0.7CaTiO3-0.3Sm1-xAlO3(CTSA,0≤x≤0.1)微波介质陶瓷,研究了Sm缺位对CTSA陶瓷的晶体结构、微观形貌以及微波介电性能的影响。结果表明,制备的CTSA陶瓷均为正交钙钛矿结构。少量的Sm缺位能够降低CTSA陶瓷的烧结温度,晶粒尺寸增加,同时气孔率增大,陶瓷的Q×f值也有显著提升。当x=0.025、烧结温度为1450℃时,CTSA陶瓷具有最佳微波介电性能:εr=45.2,Q×f=47280GHz和τf=+4.8 ppm/℃。 相似文献
5.
6.
Effect of Ordering on the Microwave Dielectric Properties of Spinel‐Structured (Zn1−x(Li2/3Ti1/3)x)2TiO4 Ceramics
下载免费PDF全文
![点击此处可从《Journal of the American Ceramic Society》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Spinel‐structured (Zn1?x(Li2/3Ti1/3)x)2TiO4 (x = 0–1) microwave dielectric ceramics were manufactured via a conventional mixed‐oxide method. The X‐ray diffraction and Raman spectra revealed that a disordered face‐centered cubic phase was found in the composition range of x < 0.5, and an ordered primitive cubic spinel solid solution was achieved as x was beyond 0.5. Such a disorder–order transition near x = 0.5 was accompanied by the variation of composition‐induced cation occupancy. The Q × f value first kept increasing up to ~160 000 (GHz) in disordered ceramics, and then sharply decreased as an ordered structure appeared at x ≥ 0.5. An obvious decrease in τf value was also accompanied by the appearance of an ordered structure. The minimum τf value (~ ?20 ppm/°C) was obtained in the x = 0.75 sample with the highest structural order degree. These results demonstrated that microwave dielectric properties of current spinel ceramics could be successfully modified by adjusting their structural order degree, which could be appropriately adopted for the design of spinel‐structured materials with favorable properties. 相似文献
7.
Structure and microwave dielectric properties of the Li2/3(1−x)Sn1/3(1−x)MgxO systems (x = 0‐4/7)
下载免费PDF全文
![点击此处可从《Journal of the American Ceramic Society》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Zixuan Fang Bin Tang Ying Yuan Xing Zhang Shuren Zhang 《Journal of the American Ceramic Society》2018,101(1):252-264
In this paper, the Li2/3(1?x)Sn1/3(1?x)MgxO (LSMxO) ceramic systems were prepared by solid‐state reaction using novel atmosphere‐controlled sintering (x = 0‐4/7). Pure Li2SnO3 was observed for x = 0, the Li2Mg3SnO6 and Li2SnO3 coexisted for x = 1/7, and the coexistence of three kinds of phases was detected for x = 1/5 and 1/4, including Li4MgSn2O7 impurity phase. Pure Li2Mg3SnO6‐like phase with cubic rock salt structure in Fm‐3m space group was obtained in the range of 1/3‐4/7. All samples showed well‐dense and smooth microstructures. The microwave dielectric properties highly depended on the phase composition, bond valence, FWHM of Raman spectrum, Raman shift, average grain sizes, and octahedral distortion. The LSMxO ceramics sintered at 1250°C for 5 hours possessed excellent comprehensive properties of εr = 15.43, Q×f = 80 902 GHz and τf = +5.61 ppm/°C for x = 1/7. Typically, the LSMxO ceramics sintered at 1350°C for 5 hours showed a maximum Q × f of 168 330 GHz for x = 1/2. 相似文献
8.
9.
Structure and electrical properties of perovskite layer (1−x)Sr2Nb2O7‐x(Na0.5Bi0.5)TiO3 high‐temperature piezoceramics
下载免费PDF全文
![点击此处可从《Journal of the American Ceramic Society》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Tao Chen Ruihong Liang Yuchen Li Zhiyong Zhou Xianlin Dong 《Journal of the American Ceramic Society》2017,100(3):1065-1072
The structure and electrical properties of perovskite layer structured (PLS) (1?x)Sr2Nb2O7‐x(Na0.5Bi0.5)TiO3 (SNO‐NBT) prepared by solid‐state reaction method are investigated. The addition of NBT is beneficial to speed up mass transfer and particle rearrangement during sintering, leading to better sinterability and higher bulk density up to 96.8%. The solid solution limit x in the SNO‐NBT system is below 0.03, over which Ti4+ is preferable to aggregate and results in the generation of secondary phase. After the modification by NBT, all SNO‐NBT ceramics have a Curie temperature Tc up to over 1300°C and piezoelectric constant d33 about 1.0 pC/N. The breakthrough of piezoelectricity can mainly be attributed to rotation and distortion of oxygen octahedron as well as higher poling electric field resulting from the improved bulk density. This study not only demonstrates how to improve piezoelectricity by NBT addition, but also opens up a new direction to design PLS piezoceramics by introducing appropriate second phase. 相似文献
10.
New Lead‐free (1−x)BaTiO3–xBi(Mg1/2Zr1/2)O3 Solid Solution with Morphotropic Phase Boundary and Diffuse Phase Transition
下载免费PDF全文
![点击此处可从《Journal of the American Ceramic Society》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Shashwat Anand Rishikesh Pandey Uma Shankar Akhilesh Kumar Singh 《Journal of the American Ceramic Society》2016,99(11):3651-3658
A new lead‐free perovskite solid solution (1?x)BaTiO3–xBi(Mg1/2Zr1/2)O3 with morphotropic phase boundary (MPB) has been developed, and its structural and dielectric properties have been investigated. Rietveld structural analysis of the X‐ray diffraction data suggest a composition‐dependent tetragonal (P4mm) to cubic () phase transition with an intermediate, phase coexistence region, demarcating the MPB. The compositions with x ≤ 0.05 are tetragonal in the P4mm space group and the compositions with x ≥ 0.25 are cubic in the space group. Coexistence of monoclinic phase (space group Cm) with tetragonal/cubic phase (space group P4mm/) is observed in the MPB region for the compositions with 0.10 ≤ x ≤ 0.22. The temperature dependence of permittivity exhibits a nonrelaxor type diffuse phase transition for all the compositions across the MPB. 相似文献
11.
本文以Li2CO3,ZnO,CaCO3,TiO2为原料,采用固相反应法制备了Li2Zn3(1-x)Ca3xTi4O12(x=0,0.05,0.1,0.15)陶瓷,并研究了CaTiO3固溶量对其显微结构和微波介电性能的影响.结果表明:Li2Zn3Ti4O12晶相中固溶CaTiO3相,晶胞参数会增大;少量CaTiO3相固溶于Li2Zn3Ti4O12陶瓷后,提高了Li2Zn3Ti4012陶瓷的烧结温度及其介电常数,但降低了其品质因素,可增大其温频系数.在1100℃/2 h烧结条件下,Li2Zn2.7Ca0.3Ti4O12陶瓷微波介电性能达到:εr=24,Q×f=50000 GHz,Tf=-25×10-6/℃. 相似文献
12.
13.
Structural and Electrical Characteristics of (1−x)Pb(Lu1/2Nb1/2)O3–xPbTiO3 Ceramics with Low PbTiO3
下载免费PDF全文
![点击此处可从《Journal of the American Ceramic Society》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Xiaoming Yang Chao He Ying Liu Xiuzhi Li Zujian Wang Shujuan Han Shilie Pan Xifa Long 《Journal of the American Ceramic Society》2016,99(10):3325-3329
A solid solution of (1?x)Pb(Lu1/2Nb1/2)O3–xPbTiO3 with composition of 0.01 ≤ x ≤ 0.08 have been prepared successfully. XRD analysis indicates the crystal structure adopts an orthorhombic (O) phase in 0.01 ≤ x ≤ 0.06 interval and becomes the coexistence of O and rhombohedral (R) phase at x = 0.07, then turns into R phase mostly at x = 0.08. In addition, two sets of superlattice reflections due to B‐site ordering and antiparallel cation displacement are distinguished by XRD and the superstructures which arise from antiparallel cation displacement disappear gradually with the increasing x. The grain size increases gradually with the increasing x, and then becomes the bimodal microstructure at x ≥ 0.06 due to the coexistence of O and R phase. The dielectric spectra exhibit Curie temperature decreases from 248°C to 147°C with increasing x from 0.01 to 0.08. As 0.01 ≤ x ≤ 0.04, the samples display typical double hysteresis loops, suggesting antiferroelectric nature, then turn into ferroelectric gradually at x = 0.05. Finally, it exhibit typical ferroelectric hysteresis loops in 0.06 ≤ x ≤ 0.08 interval. 相似文献
14.
15.
采用氧化物固相反应法制备了不同摩尔配比的(Ca0.45Sr0.55)(Zr1--xTix)O3介质陶瓷材料,研究了Ti取代Zr对(Ca0.45Sr0.55)(Zr1--xTix)O3晶相结构和介电性能的影响。结果表明:(Ca0.45Sr0.55)ZrO3和(Ca0.45Sr0.55)TiO3在Ti的取代量x≤0.12的范围内完全固溶,无另相存在,Ti取代量对晶粒尺寸的影响不大;随着Ti取代量x的增大,(Ca0.45Sr0.55)(Zr1--xTix)O3陶瓷的相对介电常数(εr)线性地增大,介电常数温度系数(τε)线性地减小,通过调整x的值,可以得到接近于0的τε值;(Ca0.45Sr0.55)(Zr0.96Ti0.04)O3在1 300℃烧结2h,1MHz下εr=35.5、tgδ1×10--4、τε=3.1×10--6/℃,具有优良的温度、频率和电场稳定性,适合于小尺寸、温度热稳定型(NP0)多层片式陶瓷电容器的制备。 相似文献
16.
Sr(Ga0.5Nb0.5)1−xTixO3 Low‐Loss Microwave Dielectric Ceramics with Medium Dielectric Constant
下载免费PDF全文
![点击此处可从《Journal of the American Ceramic Society》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Pian Pian Ma Xiao Qiang Liu Fa Qiang Zhang Juan Juan Xing Xiang Ming Chen 《Journal of the American Ceramic Society》2015,98(8):2534-2540
The microwave dielectric properties of Sr(Ga0.5Nb0.5)1?xTixO3 (x = 0, 0.1, 0.2 and 0.3) ceramics have been investigated together with their microstructures. Single‐phase solid solutions are achieved in this series of ceramics. The ordering features are comprehensively analyzed by transmission electron microscopy and Raman spectroscopy. Local 1:1 ordering in B‐site leads to a double‐cubic structure with space group , while Ti substitution disrupts this 1:1 ordering between Ga and Nb, and the metastable ordering between Ti and (Ga + Nb) is speculated to form due to their large size difference. The dielectric constant and temperature coefficient of resonant frequency increase nonlinearly as x increases, while the Qf value decreases gradually. The variation trend of Qf value is mainly attributed to the intrinsic loss because of the increasing vibrational anharmonicity by Ti substitution. The ordering transition from short coherence, long‐range ordering to short‐range ordering with increasing Ti content has an agreeable and weak effect on the Qf value. The best combination of microwave dielectric properties is achieved for the composition of x = 0.3: εr = 46.6, Qf = 42 200 GHz and τf = 5.0 ppm/°C. 相似文献
17.
(1-y)Ca1-xLa2x/3TiO3-yCa(Mg1/3Nb2/3)O3复合微波介质陶瓷的研究 总被引:3,自引:0,他引:3
采用固相合成法制备了 ( 1-y)Ca1 -xLa2x/ 3 TiO3 -yCa(Mg1 / 3 Nb2 / 3 )O3 系列微波介质陶瓷材料 ,研究了复合系统的微波介电性能、烧结性能和微观结构。研究结果表明 :在y =0 .4~ 0 .6范围内 ,体系形成了单一的钙钛矿结构 ;当复合体系组成 0 .5Ca0 .6La0 .2 67TiO3 -0 .5Ca(Mg1 / 3 Nb2 / 3 )O3 时 ,在 14 0 0℃下烧结保温 4小时所得到材料的微波介电性能最佳 ;εf=5 5 ,Q×f =45 0 0 0GHz( 7.6GHz下 ) ,τf=0 .0 4ppm/℃。 相似文献
18.
采用固相合成法制备了(Mg_(4-x)Li_(2x))(Nb_(1.92)V_(0.08))O_9系列微波介质陶瓷。通过XRD、SEM以及HP网络分析仪等测试手段对其烧结特性、晶体结构和微波介电性能进行了系统研究。结果表明:x<0.3时形成了(Mg_(4-x)Li_(2x))(Nb_(1.92)V_(0.08))O_9固溶体;x≥0.3时,除主相(Mg_(4-x)Li_(2x))(Nb_(1.92)V_(0.08))O_9外,还有少量第二相Li3Mg2NbO6生成。微波介电常数ε随x的增大持续升高,品质因数Q则先增大后减小。x=0.2,950℃,5h烧结样品的微波介电性能达到最佳:ε=12.7,Q.f=14078GHz(f0=8GHz)。 相似文献
19.
BaCu(B_2O_5)助烧对CaO-BaO-Li_2O-Sm_2O_3-TiO_2微波介质陶瓷低温烧结和介电性能的影响 总被引:1,自引:0,他引:1
研究了BaCu(B_2O_5)(简写为BCB)掺入对14CaO-4BaO-8Li_2O-12Sm_2O_3-63TiO_2(简写为CBLST)微波介质陶瓷介电性能的影响.用XRD和SEM研究其相组成及微观形貌.结果表明:BaCu(B_2O_5)掺入能显著降低CBLST陶瓷的烧结温度,由1325 ℃降至1100 ℃.1100 ℃烧结2 h后,仍包含正交钙钛矿相和棒状的BST相.掺入6wt% BaCu(B_2O_5)的CBLST陶瓷取得了较好的介电性能:Kr=87.76,tanδ=0.018,TCF=-4.27 ppm/℃(1 MHz). 相似文献