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研究了MnCO3掺杂对SnO2-ZnO-Nb2O5压敏材料压敏-介电性能的影响,研究中发现,掺入x(MnCO3)为0.08%的样品显示出最高的非线性系数(α=8.2),最高的势垒高度(φB=1.11eV),最高的击穿电场(E=466.67V/mm)。研究中同时发现,SnO2-ZnO-Nb2O5压敏材料的相对介电常数在573~673K间出现峰值,峰值随MnCO3掺入量的增加而增大,掺入x(MnCO3)为0.3%的样品在593K时,显示出最高的相对介电常数(εr=1.886×104)。 相似文献
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以新型BaCo0.05Co0.1Bi0.85O3材料为基体,掺杂不同摩尔分数x(MnO2),在840℃下烧结4h制备了NTC厚膜电阻。借助XRD、SEM和直流阻温特性测试仪,研究x(MnO2)对电阻相组成、微结构及电性能的影响。结果表明:所得的NTC厚膜热敏电阻主要物相为具有钙钛矿结构的BaCo0.05Co0.1Bi0.85O3,且表面致密。当x(MnO2)超过5%时,有新相BaMnO3开始沿晶界析出,获得小尺寸晶粒;厚膜电阻的室温电阻率ρ25及B25/85值随x(MnO2)增加而升高;当x(MnO2)为10%时,ρ25从初始的13.5?·mm升高为810.0?·mm,B25/85值从600K升高到2049K。 相似文献
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采用传统电子陶瓷工艺合成了MnCO3掺杂的Ba(Mg1/3Ta2/3)O3(BMT)微波介质陶瓷,并研究了MnCO3掺杂量对陶瓷微波介电性能的影响.实验结果发现,添加少量的MnCO3能改善BMT陶瓷的烧结性能,当w(MnCO3)=2%时,陶瓷致密化烧结温度由纯相时的1 650℃以上降至1 350℃,且表观密度提高到7.482 g/cm3以上,烧结体密度可达理论密度的98%,材料的微波性能达到最佳值:介电常数εr=25.09,品质因数与频率之积Q·f=99 000 GHz(8 GHz),谐振频率温度系数τf=0.5×10-6/℃. 相似文献
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通过在Mn-Cu-Ca系负温度系数热敏电阻器(NTCR)配方中掺杂质量分数x%的Bi2O3(x=0,0.5,1,2.4,4.8,7),采用传统固相反应法制备了单层圆片式热敏电阻元件,研究了该元件的微观结构和电性能。实验结果表明:Bi2O3存在于晶界处,Bi2O3的存在增大了元件的晶粒尺寸,同时影响元件的气孔率。Bi2O3的引入降低了元件的室温电阻率,拓宽了元件的使用温区。当Bi2O3的添加量为质量分数4.8%时,元件具有较低的室温电阻率(6?·cm)及较宽的使用温区(室温~240℃)。 相似文献
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(Ba,Co,Nb)掺杂SnO2压敏材料电学非线性的研究 总被引:2,自引:0,他引:2
通过对样品的伏安特性,晶界势垒的测量和分析,研究了BaCO3对新型(Co,Nb)掺杂SnO2压敏材料微观结构和电学性质的影响。晶界势垒高度测量表明,SnO2晶粒尺寸的迅速减小是压敏电压急剧增高的原因。对Ba含量增加引起SnO2晶粒减小的根源进行了解释。掺杂x(BaCO3)=0.4%的SnO2压敏电阻击穿电压为最小(140V/mm);掺杂x(BaCO3)-0.8%的SnO2压敏电阻具有最高非线性系数(α=19.6),最高的势垒电压(ψB=1.28eV)。 相似文献
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BaSnO3陶瓷的制备及其电性能研究 总被引:2,自引:2,他引:0
以BaCO3、SnO2为原料,微量SiO2、Bi2O3、Sb2O3作烧结助剂,Ta2O5作施主,采用传统的固相反应法,制备出相对密度达97%~99%,平均粒径约为8μm的BaSnO3半导体陶瓷。采用Na2CO3或Li2CO3与Mn(NO3)2的组合作受主掺杂可有效增强BaSnO3陶瓷的晶界效应。当x(Mn(NO3)2)为1%时,BaSnO3陶瓷电阻率达3.3×106Ω.cm,晶粒电阻率为4.3Ω.cm,视在介电常数为1.9×104(1 kHz),经电导激活能测试,估算出晶界势垒约为0.5 eV。 相似文献
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Kiju Lee Keun-Soo Kim Katsuaki Suganuma Soichi Kuritani 《Microelectronics Reliability》2011,51(12):2290-2297
The influence of the crystallographic orientation of Sn-3.0 wt%Ag-0.5 wt%Cu flip-chip joints and underfill on electromigration was investigated. The current density applied in our tests was 15 kA/cm2 at 160 °C. Various times to failure of the test samples show a clear dependence of the electromigration behavior on the Sn grain orientations. Different microstructural evolutions were observed in all solder bumps in correlation with the crystallographic orientations of the Sn grains after an electromigration test. The primary failure of the solder joints was caused by dissolution of the Cu electrode at the cathode interface. Rapid dissolution of the Cu electrode occurred when the c-axis of the Sn grains was parallel to the direction of electron flow. On the other hand, slight dissolution of the Cu electrode was observed when the c-axis of the Sn grains was perpendicular to the direction of electron flow. Some grain boundaries interrupt the migration of Cu and the trapped Cu atoms form new grains of intermetallic compounds at the grain boundaries. In addition, underfill inhibits serious deformation of solder bumps during current stressing. 相似文献
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With the reduction of dimensions in interconnect copper lines, metal resistivity is seen to increase. This phenomenon is due to electron scattering on both sidewalls and grain boundaries. To reduce the grain boundary contribution and then resistivity, it becomes important to control microstructure. This paper focuses on the grain growth mechanism in a Damascene architecture. In this architecture, trenches are filled with copper. It is shown that the remaining copper on the top surface - the overburden - plays a key role in the final microstructure in the lines. Electrical results and observations are presented and discussed in terms of overburden grains extension inside the trenches. A method is proposed to quantify this grain extension. 相似文献
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A. Goyal E. D. Specht D. M. Kroeger T. A. Mason D. J. Dingley G. N. Riley 《Journal of Electronic Materials》1995,24(12):1865-1868
The microstructure of high-Jc Bi-2223 powder-in-tube tapes was studied using x-ray and electron diffraction. Although the c-axis is nominally aligned perpendicular
to the tape surface (FWHM∼20‡), x-ray phi scans and pole figures show no evidence of any in-plane texture, either macroscopically
or locally. Electron backscatter diffraction patterns acquired in a scanning electron miscroscope (SEM) were used to measure
individual grain orientations. Grain boundary misorientation between adjacent grains was described by rotation angles and
axes (i.e. the disorientation) and compared with theoretical values of ideal coincidence site lattices (CSLs). Data collected
from over 113 spatially correlated grains resulting in 227 grain boundaries, show that over 40% of the boundaries are small
angle. In addition, 8% of the boundaries were found to be within the Brandon criterion for CSLs (larger than ⌆1 and less than
⌆50). Grain boundary “texture maps” derived from the SEM image and orientation data reveal the presence of percolative paths
between low energy boundaries. 相似文献
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E. Alleno L. Chen C. Chubilleau B. Lenoir O. Rouleau M. F. Trichet B. Villeroy 《Journal of Electronic Materials》2010,39(9):1966-1970
CoSb3 + x% CeO2 nanocomposites (x = 1, 3, 5) were synthesized by ball-milling and spark plasma sintering. Scanning electron microscopy showed that some CeO2 nano-inclusions sit at the boundaries of CoSb3 grains. These inclusions also reduce the sizes of the CoSb3 grains and crystallites by inhibiting their growth during sintering. Hall-effect measurements show that the CeO2 inclusions modify the charge-carrier concentration in CoSb3. The variations of the electrical resistivity for the 1% and 3% CeO2 samples can at least partially be attributed to these modifications of the carrier concentration. Nonetheless, the resistivity
increase in the 5% CeO2 sample can unambiguously be ascribed to the presence of the CeO2 inclusions. Thermal conductivity is systematically reduced (by more than 15% at 300 K) upon CeO2 addition. Phonon diffusion by the increased number of CoSb3 grain boundaries is one of the mechanisms involved in this reduction. 相似文献
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利用电容-电压关系研究了施主Nb掺杂BaTiO_3陶瓷离子缺位对晶界势垒的影响,得出了样品在不同冷却速率下的晶界势垒高度和载流子浓度,其值与施主掺杂含量和样品的冷却速率相关,此结果可由在高、低施主掺杂含量下,晶粒边界处和晶粒体离子缺位的区别来解释。 相似文献