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低温烧结0.5CaTiO3-0.5CaTiSiO5高频介质陶瓷 总被引:2,自引:0,他引:2
对添加2ZnO-B2O3玻璃实现0.5CaTiO3-0.5CaTiSiO5 高频介质材料900℃下低温烧结进行了系统研究。实验结果表明:添加质量分数为5%~10% 2ZnO-B2O3玻璃可使体积密度达到0.5CaTiO3-0.5CaTiSiO5理论密度的97%以上,且介电性能优异,r = 58~76,tg? 3.3?04,= (329~472)?06/℃,? 1012 cm。利用XRD、SEM和介电测量技术分析材料的晶相组成、显微结构和介电特性发现:材料由三种晶相组成,分别是单斜型CaTiSiO5、正交型CaTiO3以及一个新相,新相的生成可能是在液相烧结后期2ZnO-B2O3 玻璃在晶界处结晶而形成,低温烧结0.5CaTiO3-0.5CaTiSiO5 介质材料的介电性能很好地遵循李氏对数混合法则。 相似文献
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从经典的单一弛豫时间Debye方程着手,考虑各个弛豫时间的电偶极子对弛豫过程贡献的物理意义后,近似地获得了以任意激活能分布的电偶极子数与等温衰减电流的基本关系,即电偶极子激活能分布密度与电流I和衰减时间t的乘积成正比.数值计算结果检验该理论时表明:无论以分立或连续分布形式存在的电偶极子,精确的与近似的It-logt关系符合得相当好.该理论解决了长期以来电介质中弛豫时间分布非常难得的问题,应用于介电频谱时得到了Hamon早年提出的广泛应用的经验公式的相似结果. 相似文献
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Optical Transmission Spectra of Anodic Aluminum Oxide Membranes with a Dual Layer-by-Layer Structure 下载免费PDF全文
By adjusting the anodization voltage periodically in the process of electrochemical oxidation of Muminum and subsequent chemical etching, anodic aluminum oxide membranes with a dual periodic layer-by-layer structure are prepared. Optical transmission spectra analyses prove that the dip position is dependent on the thickness of the layer and can be easily adjusted by the anodization voltage according to the Bragg-Snell formula. This result implies that the position and width of the stop band and the pass band in the visible and near infrared wavelength region can be designed and prepared arbitrarily. It is expected that these kinds of anodic aluminum oxide membranes may find applications in the fabrication of various optical devices. 相似文献
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Influence of Light Scattering on Transmission Spectra of Photonic Crystals of Anodized Alumina 下载免费PDF全文
The light scattering is found to have a great influence on the transmission spectra of photonic crystal of anodic alumina. The incident light is diffracted by a regular array of branched channels or pores obeying the Bragg law. The intensity of transmission light decreases with the increasing etching time because of the increasing porosity or enlarging scatterers. The variation of intensity and widths of dips in transmission spectra of the porous alumina membrane versus the incidence angle shows the quite different characteristics from the other photonic crystal such as colloidal photonic crystal. 相似文献
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本文从压电学的基本定义出发,推导出两相系0—3型连通性复合压电材料的压电应变常数表达式,进一步修正了T.Furukawa压电应变常数表达式的缺陷,使理论和实验结果更相吻合。利用SEM、X-ray等先进分析手段,探讨了影响0—3型复合压电材料压电特性的机理,得出了影响压电特性的三个主要因素。 相似文献
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压电变压器的研究进展 总被引:5,自引:0,他引:5
压电变压器是一种很有发展前景的固体电子器件,有高转换效率、高能量密度、结构简单、体积小、无电磁噪声及不可燃烧等特点。介绍了压电变压器的结构、工作原理、制造方法,综述了国内外压电变压器陶瓷材料、结构设计、理论模型和应用研究的进展情况,并对压电变压器未来的发展趋势作了展望。 相似文献
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