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采用固相法制备了CaTiO3掺杂的(Ba0.65Sr0.35)TiO3(BST)陶瓷,研究了CaTiO3掺杂量对BST电容器陶瓷介电性能和微观结构的影响。结果表明:随着CaTiO3掺杂量的增加,BST陶瓷的相对介电常数(εr)先增大然后减小然后增大,介质损耗(tanδ)和交流耐压强度(Eb)先增大然后减小。当CaTiO3掺杂量为摩尔分数10%时,BST陶瓷的综合介电性能较好:εr为4480,tanδ为0.022,Eb为5.8×103V/mm(AC),容温特性符合Y5U特性。 相似文献
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采用固相法制备了添加Bi4Ti3O12(BIT)的(Ba0.71Sr0.29)TiO3(BST)陶瓷,研究了BIT的加入量对所制BST陶瓷的微观结构和介电性能的影响。结果表明:随着BIT添加量的增加,BST陶瓷的晶粒尺寸先减小后增大,相对介电常数(εr)逐渐减小,介质损耗(tanδ)先减小后增大。当添加质量分数26%的BIT于1 120℃烧结,制得的BST陶瓷综合性能较好:εr为1 700,tanδ为0.006,容温特性符合X7R的要求,耐直流电压强度为5.0×103V/mm。 相似文献
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采用射频磁控溅射法在Si和Pt/TiOx/SiO2/Si衬底上沉积了(Ba0.65Sr0.35)TiO3铁电薄膜,研究了BST铁电薄膜微观结构和介电性能。实验结果表明:衬底温度在550℃,工作气压为2.0 Pa的溅射条件下沉积的BST薄膜,经750℃退火处理30 min后,形成了完整的钙钛矿相;与Si衬底相比,在Pt衬底上制备的BST薄膜晶粒更均匀、表面平整无裂纹。在室温、频率为100 kHz条件下薄膜的介电常数ε=353.8,介电损耗tanδ=0.012 8。介电温谱结果表明制备的(Ba0.65Sr0.35)TiO3铁电薄膜居里温度在5.0℃左右。 相似文献
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B2O3掺杂对Ba0.6Sr0.4TiO3/MgO陶瓷介电性能的影响 总被引:1,自引:1,他引:0
采用XRD和SEM对B2O3掺杂Ba0.6Sr0.4TiO3/MgO(简称为BSTM)陶瓷致密化行为和介电性能进行了研究。结果表明:掺杂适量B2O3可明显降低BSTM陶瓷的烧结温度,在1480℃时即可烧结致密化,比未掺杂的BSTM陶瓷烧结温度降低70℃;掺杂量不同,则B2O3在陶瓷体中的存在形式不同,引起其介电性能相应变化;1480℃下烧结,B2O3掺杂量为0.8%(质量分数)时,10kHz下测得试样的εr为138,tanδ为0.0034,εr可调率达12.6%(3MV/m),性能有所提高。 相似文献
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采用固相反应法制备了V2O5掺杂的MgTiO3-CaTiO3(MCT)介质陶瓷。研究了V2O5掺杂量对陶瓷晶相组成、烧结温度和介电性能的影响。结果表明:V2O5掺杂的MCT陶瓷的主晶相为MgTiO3和CaTiO3两相结构,当掺杂量较低时,有第二相CaVO3产生;V2O5掺杂能降低MCT陶瓷的烧结温度并使其介电性能得到改善。当x(V2O5)为1%时,在1250℃烧结2.5h获得最佳性能:εr为20.17,tanδ为2×10–3,αε为4.9×10–5/℃。 相似文献
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采用轧膜成型工艺制备了掺杂有稀土氧化物的钛酸锶钡(BST)陶瓷,研究了不同稀土(Sc,Y,La,Ce,Pr,Nd和Sm)氧化物掺杂对其微观形貌、介电性能和热释电性能的影响。结果表明,Sc掺杂大幅降低了BST陶瓷的εr,严重劣化了BST陶瓷的热释电性能,并引起了长条状晶粒在BST陶瓷中的出现;Y掺杂则显著提高了BST陶瓷的热释电性能,并最终获得了εr为7111、tanδ为0.65×10–2、热释电系数p为5.5×10–7C·cm–2·℃–1、探测率优值Fd为8.49×10–5Pa–1/2的热释电BST陶瓷材料,有望在红外探测领域得到应用。 相似文献
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The article describes a model representation of radar probing data in form of a mixture of background and target samples, which is the sum of two random variables with very different parameters. For model development we research the behavior of the central moments of the distribution mix without assuming the distribution law form. An example it is described the detection of the signal at the output of compression system of chirp ionosonde. 相似文献
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解决IP网QoS问题是目前通信领域的研究热点之一.虽然研究已经取得了一定的进展,但人们对于IP 网QoS本身的含义及相关的问题还有着不同的理解.本文将从IP网QoS的定义入手讨论相关的一些问题以及解决IP网QoS问题所做的各种努力. 相似文献
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《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》1968,56(6):1024-1032
Assuming that visual responses are due to the action of particles on the membrane of the visual cells, the stochastic variability of the response should be a function of the number of particles producing it. Quantitative predictions can be made with the aid of a model proposed in previous articles. It is found that responses produced in visual cells of Limulus by absorption of a single photon have the stochastic properties which would be expected if the response to one photon were brought about by 25 particles. It is concluded from this that the processes leading to visual responses produce multiplication of particles. The effects of temperature and of metabolic poisons suggest that these processes are of chemical nature. 相似文献
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罗晓羽 《信息技术与标准化》2008,(6):37-39
论述了推进电子行业标准制修订项目计划管理信息化的必要性.并提出了具体措施;详细介绍了电子行业标准制修订项目计划管理数据库的设计思路和实现方法.阐述了对后续工作的几点思考. 相似文献
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对影响镍镀层内应力的因素做了介绍和分析,提出了对收缩应力的一种解释,提供了排除这些因素影响的方法,指出重视镀液的管理是减少各种影响内应力因素的主要办法。 相似文献
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By means of exact conformal mapping method we have defined character of dependence of squares amounts of angular part of film
element on angled part dimension. We propose relations, approximating obtained dependence. Calculation results and experimental
researches of large-scale models are represented. 相似文献
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Moshrefzadeh R.S. Radcliffe M.D. Lee T.C. Mohapatra S.K. 《Lightwave Technology, Journal of》1992,10(4):420-425
The temperature dependence of refractive index of polymer films was determined for a number of slab waveguides by a grating coupling method. This dependence was examined as a function of parameters such as molecular weight and glass transition temperature of the polymer. Temperature-induced changes in N TE-N TM , N being the effective index, were studied systematically for different slab waveguide compositions. It is shown that with proper device design and choice of polymeric materials, thermal effects can be reduced 相似文献
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A. M. Emel’yanov 《Semiconductors》2010,44(9):1134-1139
A method for analyzing the luminescence spectra of semiconductors is suggested. The method is based on differentiation of
the spectra. The potentialities of the method are demonstrated for luminescence in the region of the fundamental absorption
edge of Si and SiGe alloy single crystals. The method is superior in accuracy to previously known luminescence methods of
determining the band gap of indirect-gap semiconductors and practically insensitive to different conditions of outputting
radiation from the sample. 相似文献