222 resultados para ZRO2


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测量了End-Hall离子源在不同条件下的离子束流密度,在不同离子束流密度下进行了心离子辅助沉积ZrO2薄膜的实验,研究了离子束流密度对薄膜折射率、晶相的影响.根据动量传递模型分析了离子束流密度对薄膜折射率的作用;根据热尖峰理论证明了一定条件下离子束流密度不会影响薄膜晶体结构。

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建立了缺陷吸收升温致薄膜激光损伤模型,该模型从热传导方程出发,考虑了缺陷内部的温度分布以及向薄膜的传导过程,通过引入散射系数简化了Mie散射理论得出的吸收截面.对电子束蒸发沉积的ZrO2:Y2O3单层膜进行了激光破坏实验,薄膜样品的损伤是缺陷引起的,通过辉光放电质谱法对薄膜制备材料的纯度分析发现材料中的主要杂质元素为铂,其含量为0.9%.利用缺陷损伤模型对损伤过程进行了模拟,理论模型和实验结果取得了较好的一致性.

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Glancing angle deposition is a novel method to prepare graded index coatings. By using this method and physical vapour deposition, ZrO2 is used to engineer graded index filter on BK7 glass substrate. Controlling the deposition rate and the periodic oscillation of oblique angle of deposited material, a 10-period graded index ZrO2 filter with high reflection near 532 nm and high transmittance at wavelength 1064 nm is fabricated. The causes of difference between the theoretical and experimental results are discussed in detail. The material properties and electron gun nonlinearity are possibly the main origins of the difference, which result in the variations in both thickness control and deposition rate of the Elm material.

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Thin films of ZrO2, HfO2 and TiO2 were deposited on kinds of substrates by electron beam evaporation (EB), ion assisted deposition (IAD) and dual ion beam sputtering (DIBS). Then some of them were annealed at different temperatures. X-ray diffraction (XRD) was applied to determine the crystalline phase and the grain size of these films, and the results revealed that their microstructures strongly depended on the deposition conditions such as substrate, deposition temperature, deposition method and annealing temperature. Theory of crystal growth and migratory diffusion were applied to explain the difference of crystalline structures between these thin films deposited and treated under various conditions. (c) 2007 Elsevier B.V. All rights reserved.

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用电子束蒸发法制备出四种不同Y2O3含量的Y2O3稳定ZrO2(YSZ)薄膜,用X射线衍射和透射光谱测定薄膜的结构和光学性能.结果表明:随着Y2O3含量的增加,ZrO2薄膜从单斜相向高温相(四方相和立方相)转变,获得了结构稳定的YSZ薄膜;YSZ薄膜的晶粒尺寸都比ZrO2薄膜的大,但随着Y2O3加入量的增加,晶粒尺寸有减小的趋势,薄膜表面也趋向光滑平整.所有YSZ薄膜的透射谱线都与ZrO2薄膜相似,在可见光和红外光区都有较高的透过率.Y2O3的加入还可以改变薄膜的折射率,在一定范围内可得到所需的任意折射率

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用电子束蒸发沉积方法在X切LBO(X-LBO)晶体上镀制了两种不同膜系结构的1064和532nm倍频增透膜,其中一种膜系结构为基底/ZrO2/Y2O3/A12O3/SiO2/空气,另一种为基底/0.5Al2O3/ZrO2/Y2O3/A12O3/SiO2/空气,两种膜系结构的主要差别在于有无氧化铝过渡层。测量了薄膜的反射率光谱曲线,发现两种增透膜在1064和532nm处的反射率均小于0.5%,实际镀制结果与理论设计曲线的差异主要是由材料折射率的变化引起的。且对样品在空气环境中进行了温度为473K的退火处理,

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用电子柬蒸发的方法在BK7玻璃上制备了ZrO2单层膜和ZrO2/SiO2高反膜,利用掺Ti:sapphire飞秒激光系统输出的中心波长为800nm,脉宽为50fs的激光脉冲对这两种样品进行了激光损伤阈值测试.实验结果表明,ZrO2单层膜的阂值比ZrO2/SiO2高反膜的高;这与传统的纳秒脉冲激光的损伤情况相反.利用光离化和碰撞离化激发电子到导带,形成电子等离子体基本模型并对此现象进行了解释.同时,用显微镜对样品的损伤形貌进行了观测,对损伤的特点进行了表征.

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Zirconium dioxide (ZrO2) thin films were deposited on BK7 glass substrates by the electron beam evaporation method. A continuous wave CO2 laser was used to anneal the ZrO2 thin films to investigate whether beneficial changes could be produced. After annealing at different laser scanning speeds by CO2 laser, weak absorption of the coatings was measured by the surface thermal lensing (STL) technique, and then laser-induced damage threshold (LIDT) was also determined. It was found that the weak absorption decreased first, while the laser scanning speed is below some value, then increased. The LIDT of the ZrO2 coatings decreased greatly when the laser scanning speeds were below some value. A Nomarski microscope was employed to map the damage morphology, and it was found that the damage behavior was defect-initiated both for annealed and as-deposited samples. The influences of post-deposition CO2 laser annealing on the structural and mechanical properties of the films have also been investigated by X-ray diffraction and ZYGO interferometer. It was found that the microstructure of the ZrO2 films did not change. The residual stress in ZrO2 films showed a tendency from tensile to compressive after CO, laser annealing, and the variation quantity of the residual stress increased with decreasing laser scanning speed. The residual stress may be mitigated to some extent at proper treatment parameters. (c) 2007 Elsevier GmbH. All rights reserved.

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This paper describes the preparation and the characterization Of Y2O3 stabilized ZrO2 thin films produced by electric-beam evaporation method. The optical properties, microstructure, surface morphology and the residual stress of the deposited films were investigated by optical spectroscopy, X-ray diffraction (XRD), scanning probe microscope and optical interferometer. It is shown that the optical transmission spectra of all the YSZ thin films are similar with those of ZrO2 thin film, possessing high transparency in the visible and near-infrared regions. The refractive index of the samples decreases with increasing of Y2O3 content. The crystalline structure of pure ZrO2 films is a mixture of tetragonal phase and monoclinic phase, however, Y2O3 stabilized ZrO2 thin films only exhibit the cubic phase independently of how much the added Y2O3 content is. The surface morphology spectrum indicates that all thin films present a crystalline columnar texture with columnar grains perpendicular to the substrate and with a predominantly open microporosity. The residual stress of films transforms tensile from compressive with the increasing Of Y2O3 molar content, which corresponds to the evolutions of the structure and packing densities. (C) 2008 Elsevier Ltd. All rights reserved.

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采用自制掺摩尔分数12%的Y2O3的ZrO2混合颗粒料为原料,在不同的沉积温度下用电子束蒸发方法沉积氧化钇稳定氧化锆(YSZ)薄膜样品。利用ZYGOMarkⅢ-GPI数字波面干涉仪对氧化钇稳定氧化锆薄膜的残余应力进行了研究,讨论了沉积温度对残余应力的影响。实验结果表明:随沉积温度升高,氧化钇稳定氧化锆薄膜中残余应力状态由张应力变为压应力,且压应力值随着沉积温度升高而增大;用X射线衍射仪表征了不同沉积温度下氧化钇稳定氧化锆薄膜的微观结构,探讨了薄膜微观结构与其应力的对应关系,并对比了纯ZrO2薄膜表现出的应力状态。

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用辉光放电质谱法和二次离子质谱仪测定了两种HfO2材料及它们相应的单层膜中的杂质含量,结果发现,无论是在体材料中还是在用电子束蒸发技术沉积的材料单层薄膜中,ZrO2都是这两种HfO2材料中最主要的杂质。而且,这两种HfO2材料中Zr含量的差别远远大于Ti、Fe含量的差别,这说明Zr含量的差别正是引起两种HfO2膜层光学性能差别的原因。用这两种不同纯度的HfO2材料与同一纯度的SiO2材料组合,沉积形成266nm的紫外反射镜,实验结果表明这两种反射镜的反射率分别在99.85% 和 99.15%左右。这个结果与依据单层膜得出的光学常数所设计的结果符合的很好。

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Influence of ZrO2 in HfO2 on the reflectance of HfO2/SiO2 multilayer at 248 nm was investigated. Two kinds of HfO2 with different ZrO2 content were chosen as high refractive index material and the same kind of SiO2 as low refractive index material to prepare the mirrors by electron-beam evaporation. The impurities in two kinds of HfO2 starting coating materials and in their corresponding single layer thin films were determined through glow discharge mass spectrum (GDMS) technology and secondary ion mass spectrometry (SIMS) equipment, respectively. It showed that between the two kinds of HfO2, either the bulk materials or their corresponding films, the difference of ZrO2 was much larger than that of the other impurities such as Ti and Fe. It is the Zr element that affects the property of thin films. Both in theoretical and in experimental, the mirror prepared with the HfO2 starting material containing more Zr content has a lower reflectance. Because the extinction coefficient of zirconia is relatively high in UV region, it can be treated as one kind of absorbing defects to influence the optical property of the mirrors. (C) 2008 Elsevier B.V. All rights reserved.

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Large-area concave refractive microlens arrays, or concave template structures, and then the non-refractive-index-gradient type of planar refractive microlens arrays in InP and quartz substrates, are fabricated utilizing the method consisting of conventional UV photolithography, thermal shaping of concave photoresist microlenses, etching with an argon ion beam of large diameter, and filling or growing optical medium structures onto the curved surfaces of preshaped concave templates. Several key conditions for fabricating concave and also planar microlenses are discussed in detail. The concave structures obtained are characterized by scanning electron microscope and surface profile measurements. The far-field optical characteristics of quartz/ZrO2 planar refractive microlens arrays have been acquired experimentally. (c) 2008 Society of Photo-Optical Instrumentation Engineers.

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酸催化剂可以用来催化烃类裂解、重整、异构、烯烃水和、烷基化和酯化等重要化学反应,在石油炼制和石油化工领域有极其广泛的应用。与传统液体酸相比,新型固体酸催化剂具有容易与反应物和产物分离、易再生、不腐蚀反应器、环境污染少等优点,因此研究开发环境友好的新型固体酸催化剂成为国际上催化领域研究的热点。本论文研究新型固体酸催化剂的酸强度和延长催化剂使用寿命的方法,具有很高的工业实用价值和理论意义。 研究了固体酸催化剂在正己烷异构化和异丁醇脱水这两个反应的催化活性,结果显示:1)复合超强酸催化剂,2)Hβ及其负载催化剂,3)负载杂多酸,4)ZrO2·Bi2O3、ZrO2·CaO四类催化剂酸强度较高且强度大小为:1>2≈3>4。氢溢流的引入提高了Pt-SO42-/ ZrO2催化剂在反应中的催化活性,一定程度上弥补了酸强度的不足,也使一些原本没活性的催化剂有了一定的活性,如MOO3催化剂。 研究了异丁烷在12wt%V2O5/γ-Al2O3催化剂上脱氢制异丁烯的反应和异丁烯在50wt%HSiW/SiO2、Amberlyst-15和Amberlyst-35树脂催化剂上的迭代反应,均获得了较好的催化活性。 首次将催化剂表面的疏油性应用在酸催化领域,在硅胶负载的钨硅酸中掺杂不同含量聚四氟乙烯制备出具有一定疏油性的催化剂,用异丁烯迭代反应作为探针反应着重研究了催化剂表面的适当疏油性对催化剂的寿命和产物选择性的影响。结果显示催化剂表面的疏油性不仅提高了C8 =的选择性并且有效延长催化剂寿命。这主要是由于催化剂表面具有适当的疏油性,反应的中间产物C8=易于从具有疏油性的表面脱附,减少了C8=继续在催化剂表面进行连续反应生成C12=和C16=的机会,因此提高了C8=的选择性。这可能促进了更高的产物选择性,低的积炭量和较长的催化剂使用寿命。 研究了催化剂表面的疏水疏油性在醋酸与正丁醇的酯化反应中的应用。结果显示,当酯化反应产物为液相时,催化剂表面的疏水疏油性非常有利于产物从催化剂表面脱附,能有效提高正丁醇的转化率。 关键词:酸强度,钨硅酸,聚四氟乙烯,疏油性,寿命

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世界能源短缺和环境污染问题日趋严重,因此需要发展能源转换效率高、对环境污染低并便于应用的绿色能源技术。固态氧化物燃料电池(SOFC,Solid Oxide Fuel Cell)因其效率高、对环境友好等优点被认为是二十一世纪最有前景的能源技术。SOFC的关键是固体电解质的研究。目前广泛使用的固体电解质8YSZ(8mol%Y2O3稳定化的ZrO2)仅在1000oC以上有高的电导率。所以,探索新的、在中温区具有高离子电导率的电解质材料具有重要的意义。另外,也可以采用新的方法改善固体氧化物电解质的导电性,比如掺杂、将材料纳米化等。 在本论文中,通过共沉淀法合成了La2Mo2O9化合物,并与溶胶凝胶法合成的样品进行比较,在同样的烧结条件下,共沉淀法合成的La2Mo2O9化合物具有更高的致密度,而且由于很少引入杂质,电导率得到明显提高,在800oC时达到0.15 S.cm-1。利用同样的方法通过对La2Mo2O9进行微量磷的掺杂,降低了材料在高温时的相转变温度,基本实现了低温电导率的提高。另外,我们还对La2Mo2O9化合物进行了高压烧结研究。实验表明,La2Mo2O9纳米粉末经过700oC高压烧结后得到了致密样品,样品保持了纳米尺度,相对密度达到99%。样品由原先单斜相的La2Mo2O9变为镧钼化合物的混合物,当其在常压下800oC退火后样品又回复到单一的La2Mo2O9相,此时样品粒径大约为50nm,通过这种方法,纳米La2Mo2O9陶瓷被制得。 通过在不同温度高压烧结的方法得到了致密的8YSZ材料。样品的相结构对电导率有很大的影响,在1450oC高压烧结10min得到了立方相与少量四方相的样品,由于具有很高的致密度,得到了相对高的低温电导率。而在1000oC高压烧结10min后的样品,其相结构转变为四方相和单斜相,电导率也相应降低。高压烧结后的样品在1650oC常压退火后,样品又回复到立方相,其电导率又相应提高。 磷灰石结构化合物由于烧结温度很高,也可以通过高压烧结的方法在低温下得到致密烧结体。本论文中,采用高压烧结的方法得到了致密的纳米La9.33Si6O26块体材料,并与常压烧结的样品进行比较,其电导率得到了提高。但是和文献报道值比较,其电导率还是相对较低。这主要是由于样品中含有少量La2SiO5杂相。提高样品的纯度将更有利于电导率的提高。 作为固体电解质的氧化铋基材料极大地吸引了人们的兴趣。本文通过溶胶凝胶法合成了Bi2Ga4O9化合物,首次研究了它的电学性质和化学稳定性。电导率随氧分压的减小而减小,表明化合物中p型电子导电的存在。在500oC时,化合物的离子迁移数小于0.50,化合物是混合导体。