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液相法是制备性能良好的钛酸锶钡粉体的有效方法.介绍了国内外近年来液相法合成钛酸锶钡的研究现状及其进展,重点介绍了几种基本的液相合成法:化学沉淀法、溶胶-凝胶法、水热合成法、喷雾热解法和燃烧合成法,比较了其优缺点,对基本液相法的新进展进行了简要介绍,并对进一步的研究方向和发展趋势提出了见解. 相似文献
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钛酸锶钡是一种具有钙钛矿结构的铁电材料,在外加直流偏置电场作用下,钛酸锶钡(BSTO)的介电常数随着电场强度增加而降低,是目前相控阵天线移相器材料的研究热点.本工作以双层流延法制备了具有STO-BTO-STO-BTO-STO-…的多层叠合钛酸锶钡陶瓷,并通过控制多层陶瓷材料的烧结温度、烧结时间,以获得烧结后钛酸锶、钛酸钡双层扩散成分梯度分布的陶瓷材料,从而达到调节介电性能的目的.双层流延法制备的钛酸锶钡叠层材料通过介电性能测试发现,BTO-STO复合结构大大降低了材料的介电常数,样品介电常数均可降至300以下,最低可达210,介电损耗tanδ可降至0.02以下.BTO-STO多层陶瓷的介电可调性也有较大幅度的降低,该现象可由介质混合法则解释.通过SEM的分析结果可以看到清晰BTO-STO周期层状结构,经烧结后流延层间结合紧密.随着烧结温度的提高,烧结时间的增加,试样晶粒明显长大,而层间界线也更为模糊. 相似文献
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《Composites》1989,20(4):383-388
Hybrid composites of glass and jute fabric modified by treatment with γ-aminopropyl trimethoxy silane (silane), isopropyl triisostearoyl titanate (titanate) and tolylene diisocyanate (tdi) were fabricated using unsaturated polyester resin (usp). An improvement in mechanical properties of laminates was observed when jute fabric was modified by titanate treatment. Better retention of mechanical properties in humid environments was observed in these laminates. 相似文献
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椰壳纤维/IPC复合材料的应力-应变曲线拟合及界面改进 总被引:1,自引:0,他引:1
采用扫描电子显微镜、万能材料试验机对椰壳纤维/抗冲共聚聚丙烯(IPC)界面改进复合材料的断面形貌、力学性能进行了研究。利用高斯函数模型拟合椰壳纤维/IPC复合材料的应力-应变曲线,得到其数学表达式,计算曲线下的面积,得到各料的韧性模量。结果表明,马来酸酐接枝聚丙烯(MAH-g-PP)作为相容剂改性的复合材料各项力学性能... 相似文献
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采用填料对含二氮杂萘结构的聚醚砜酮(PPESK)进行填充改性,能够快捷有效的提高其性能,为此采溶液共沉析的方法制备了含二氮杂萘结构的聚芳醚砜酮/钛酸钾晶须(PPESK/Whisker)复合材料.使用不同比例的钛酸酯偶联剂进行晶须表面处理,研究了晶须表面处理和晶须含量对PPESK复合材料机械性能的影响;考察了复合材料的热性能,并用扫描电镜观察了复合材料的形貌.结果表明,钛酸钾晶须作为填充材料,使得复合材料机械性能得到明显改善;对晶须进行适当的表面处理后,晶须与PPESK基体的相容得到改善. 相似文献
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The photoelectronic properties of layered titanate nanostructures can be adjusted by changing the nature and bonding state of ions in the interlayer region. We studied the optical properties of titanate nanowires and nanotubes obtained after soft-chemical treatment of TiO2 anatase powders. A photoluminescence emission process originating from exciton states trapped in [TiO6] units was observed in anatase TiO2 and, with significantly enhanced intensity, in nanowires made of titanate nanosheets. On the basis of a correlation between emission intensity and the concentration of intercalated alkali ions, we conclude that protonation of the [TiO6] octahedra that constitute the titanate sheet structure suppresses radiative deactivation of trapped excitons and can be reversed by ion exchange. 相似文献
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对比研究了典型铅系钙钛矿型弛豫铁电陶瓷独石电容器及钛酸钡基独石电容器的介电特性随温度、电场等条件下的变化规律。结果表明,尽管在弱电场下弛豫体陶瓷与钛酸钡陶瓷的介电行为存在较大的差别,但在强电场下这种差别会减小。从应用的角度看,两种电容器的介电性能在强电场下的相似性是弛豫体电容器取代传统钛酸钡电容器进入大规模应用的重要保证。同时,弛豫铁电陶瓷具有较高的介电常数,这一优势可为电容器设计中提高元件综合性 相似文献
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E. K. Hollmann V. I. Gol’drin V. E. Loginov A. M. Prudan A. V. Zemtsov 《Technical Physics Letters》1999,25(7):549-550
Results are presented of experiments to deposit barium strontium titanate films on an r-cut sapphire substrate with a strontium titanate sublayer. It is shown that the use of a strontium titanate sublayer can
ensure that the dielectric properties of barium strontium titanate films have a weak temperature dependence over a wide temperature
range. Moreover, the parameters of the films are consistent with those required to fabricate microwave microelectronics devices.
Pis’ma Zh. Tekh. Fiz. 25, 1–5 (July 26, 1999) 相似文献
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Homogeneous Ba–Ti–B–Si, Ba–Ti–Al–Si and Ba–Ti–B gels have been successfully prepared by the sol–gel process. A novel method
is presented for fabricating barium titanate glass-ceramics by sintering the gel powders with small barium titanate crystallites.
The structural development, grain size, crystallization process and dielectric properties were systematically studied by differential
thermal analysis, thermogravimetric analysis, X-ray diffraction techniques, scanning electron microscopy and dielectric measurements.
The glass-ceramic samples were sintered at lower temperatures compared to the barium titanate ceramic sintering, and showed
improved dielectric properties. It was found that the small size effect of the barium titanate grains on the dielectric constant
in the glass-ceramics was quite evident. Ferroelectric hysteresis loop analyses were also performed to manifest the ferroelectric
nature of the barium titanate grains in situ grown from the gels.
This revised version was published online in November 2006 with corrections to the Cover Date. 相似文献
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具有高介电常数(k)的钛酸钡/聚合物复合材料,兼有钛酸钡陶瓷和聚合物的各自优势,是一种有广泛应用前景的电子材料,因而备受关注。综合给出了近5年来高性能钛酸钡/聚合物复合材料的研究进展,分析指出了原材料选择、制备工艺及其对复合材料介电性能的影响,概括介绍了这类复合材料的主要应用,预测展望了其未来的发展趋势。 相似文献