共查询到19条相似文献,搜索用时 125 毫秒
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含纳米金属阵列阳极氧化铝膜的偏振特性 总被引:3,自引:1,他引:2
利用阳极氧化铝的纳米多孔阵列结构特性,将金属Cu电镀到氧化铝的孔中,得到含有金属纳米阵列的氧化铝膜。实验发现,这种氧化铝膜确实象金属线栅偏振器一样表现出偏振特性,是一种新型微偏振器件。它在波长大于500nm时吸收很小,在波长为1.5μm时有高达67.1%的透射率和25.6dB的消光比。该氧化铝膜的偏振特性与阳极氧化和电镀条件有关。随着电流密度的增大,金属柱增多,光学损失增大,透射率降低,而偏振度增大。但是当电流密度增加到某一数值时,偏振度降低。通过优化制备条件,可得到高效率的氧化铝微偏振器。这种微偏振器制作简单,体积小,在光电通信领域有着非常广泛的应用前景。 相似文献
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采用二步阳极氧化法在草酸溶液中制备了高度有序的多孔阳极氧化铝(Porous Anodic Alumina,PAA)薄膜。以多孔氧化铝薄膜为模板,采用真空电子束蒸发的方法在多孔氧化铝模板上制备出了高度有序的金属银纳米点阵列体系。扫描电镜(SEM)测试结果表明,所制备的金属银纳米点阵列与多孔阳极氧化铝膜的多孔阵列具有完全相同的有序结构,阵列中银纳米颗粒的形状接近球形,其直径大约为70nm,与氧化铝模板的孔径基本一致。研究了高度有序银纳米点阵列的形成过程。 相似文献
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金属线栅偏振器是一种新兴的基于微纳结构的光学偏振器件, 体积小、性能高、易集成.但在紫外和可见光波段, 通过缩小线栅的特征尺寸来提高消光比的方法已经受到纳米制作工艺的限制, 因此需要新的结构来提高其偏振特性.双层金属线栅结构仅在特定波段上提高 器件的偏振特性. 在此基础上, 提出一种间距可调谐的金属线栅偏振器结构, 通过调谐两层金属线栅之间的距离来确保偏振器极高的消光比和很强的透过率. 利用VirtualLab软件的傅里叶模式方法, 计算了可调谐型金属线栅偏振的透过率和消光比. 数值仿真结果表明, 双层可调谐型金属线栅结构在整个紫外、 可见光波段极大地提高了透射光的消光比和透过率.
关键词:
线栅偏振器
可调谐结构
消光比
压电陶瓷 相似文献
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铜钴合金纳米有序阵列的光学特性 总被引:1,自引:0,他引:1
用电化学法制备了高度有序的多孔阳极氧化铝模板, 选用CoSO4和CuSO4的混合溶液为电解液,用交流电化学沉积法在多孔阳极氧化铝的柱形微孔内制备铜钴合金纳米线有序阵列.分别用扫描电镜(SEM),X 射线衍射仪(XRD)对多孔氧化铝模板和纳米线阵列的微观形貌和结构进行分析.结果显示,制备的合金纳米线表面光滑、均匀,纳米线中的晶粒在长过程中有(111) 晶面的择优取向.用UV3101分光光度计测试了铜钴合金多孔铝复合结构的透射光谱及偏振光谱表明,合金纳米复合结构在可见及近红外波段具有良好的透射比和消光比;铜钴合金纳米复合结构的确能够改善单一金属的特性,比如在近红外光区,其消光比(30 dB)优于铜纳米复合结构(17 dB). 相似文献
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以有序的多孔氧化铝为模板,利用交流电在孔洞中沉积金属铜得到纳米Cu粒子/Al2O3组装体系.透射电镜观察显示随着交流电沉积时间的延长,孔洞中纳米Cu粒子数量增加.测量了纳米Cu粒子/Al2O3组装体系的紫外可见光吸收光谱,发现随着孔洞中纳米Cu粒子数量增加,纳米Cu粒子/Al2O3组装体系的吸收带边大幅度红移;根据雷利散射引起的消光增强解释了组装体吸收带边红移的原因.同时发现
关键词:
纳米Cu
模板合成
光吸收 相似文献
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Z.H. Su X.C. Li F.M. Qu H.J. Zhou L. Liu Q. Zhou L. Zhang H. Wang M. Feng Y.F. Wang X.W. Cao 《Solid State Communications》2009,149(41-42):1782-1785
Alumina nanowire array standing on porous anodic alumina (PAA) membrane has been directly and efficiently synthesized in oxalic acid solution by one-step electrochemical anodic oxidation with changing anodic voltages. The morphology of the nanowires on PAA was observed by scanning electron microscopy (SEM). The different patterns on the surface of the sample were synthesized due to the reaction time. The fine structure of the patterns has shown that the pattern is composed of the alumina nanowire array and the morphologies of the patterns can mainly be attributed to the differences in the length of the alumina nanowires. The method of selected area electron diffraction (SAED) for transmission electron microscopy (TEM) has shown that these nanowires are amorphous. An etching model was given to explain the formation mechanism of the amorphous alumina nanowires. 相似文献
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《Journal of Electron Spectroscopy and Related Phenomena》2005,148(3):151-157
To understand spectral features of humic acid (HA) C 1s-near edge X-ray absorption fine structure (NEXAFS) with and without metal ion complexation, a set of model compounds is investigated. Halogenated benzoic acids and anthranilic acid are examined to demonstrate the effect of electron withdrawing groups on the C 1s-NEXAFS spectra of complex organic acids, including HA. The peak positions for aromatic and carboxylic groups in these spectra are in agreement with common assignments. The spectral position of the peak for substituted aromatic carbon shifts with increasing electronegativity of the substituent to higher photon energies. Polyacrylic acid (PAA) and different PAA metal ion complexes are investigated as model substances for metal cation complexation by HA. Tb(III)-, Zr(IV)- and U(VI)–PAA exhibit general spectral signatures previously observed for the PAA/Eu(III)–PAA system. For these different metal cations, similar spectral changes and distinct variations in peak intensities are observed going from the uncomplexed to the metal-loaded macromolecules. These spectral changes are comparable to those for U(VI)- and Th(IV)–HA systems. 相似文献
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The investigation of the electronic structure of polyacenacene (PAA) has been performed on the basis of the tight-binding SCF-MO (self-consistent field-molecular orbital) method. The predicted skeleton for PAA is of an aromatic structure without the band gap. Hence it can be considered that PAA will show the metallic property. In this connection one could regard PAA as a one-dimensional graphite. 相似文献
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In this review paper, we examine some of the recent advances in the parametric acoustic array (PAA) since it was first applied in air in 1983 by Yoneyama. These advances include numerical modelling for nonlinear acoustics, theoretical analysis and experimentation, signal processing techniques, implementation issues, applications of the parametric acoustic array, and some safety concerns in using the PAA in air. We also give a glimpse on some of the new work on the PAA and its new applications. This review paper gives a tutorial overview on some of the foundation work in the PAA, and serves as a prelude to the recent works that are reported by different research groups in this special issue. 相似文献
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Si nanopillar arrays with nanocrystals produced by template-induced growth at room temperature 下载免费PDF全文
Well-aligned and closely-packed silicon nanopillar (SNP) arrays are fabricated by using a simple method with magnetron sputtering of Si on a porous anodic alumina (PAA) template at room temperature. The SNPs are formed by selective growth on the top of the PAA pore walls. The growth mechanism analysis indicates that the structure of the SNPs can be modulated by the pore spacing of the PAA and the sputtering process and is independent of the wall width of the PAA. Moreover, nanocrystals are identified by using transmission electron microscopy in the as-deposited SNP samples, which are related to the heat isolation structure of the SNPs. The Raman focus depth profile reveals a high crystallization ratio on the surface. 相似文献
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The angular resolved energy distribution of true secondary electrons emitted normal to a clean W(100) surface has been measured with a 180° Spherical Deflector Analyzer. While significant discrepancies are found with earlier secondary emission data, good agreement exists with angular resolved photoemission spectra. Comparison to recent band structure calculations (density of states effects) is made. The fine structure of the secondary emission spectrum is fully explained by numerical results obtained by means of a quantitative theory of angular resolved secondary emission. Further, the fine structure corresponds closely to reflection coefficient data. 相似文献
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采用二步阳极氧化法在草酸溶液中制备了多孔阳极氧化铝(PAA)薄膜。借助于扫描电子显微镜(SEM)分析了多孔阳极氧化铝薄膜的微观形貌。结果发现,在其表面孔径为30~40nm的六边形孔洞分布均匀,且垂直于表面平行生长。依据PAA透射光谱的实验数据,采用极值包络线算法计算出了PAA薄膜的复折射率以及光学能隙等光学常数。通过分析吸收系数与入射光子能量之间的关系发现,PAA薄膜具有直接带隙半导体的电子结构特征,而且由理论计算得到的PAA的带隙能与其光致发光谱的峰位能是一致的。 相似文献
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N.L. Dygert A.P. Gies K.E. Schriver R.F. Haglund Jr. 《Applied Physics A: Materials Science & Processing》2007,89(2):481-487
We report the successful deposition of a polyimide precursor using resonant infrared laser ablation (RIR-LA). A solution of
poly(amic acid) (PAA) dissolved in N-methyl-2-pyrrolidinone (NMP), the melt processable precursor to polyimide, was frozen
in liquid nitrogen for use as an ablation target in a high-vacuum chamber. Fourier transform infrared spectroscopy was used
to determine that the local chemical structure remained unaltered. Gel permeation chromatography demonstrated that the transferred
PAA retained its molecular weight, showing that RIR-LA is able to transfer the polymer intact, with no detectable chain fragmentation.
These results are in stark contrast to UV-processing which degrades the polymer. After deposition the PAA may be removed with
a suitable solvent; however, once the material has undergone cyclodehydration it forms an impenetrable three-dimensional network
associated with thermosetting polymers. The transfer of uncured PAA precursor supports the hypothesis that RIR-LA is intrinsically
a low temperature process, because the PAA is transferred without reaching the curing temperature. The RIR-LA also effectively
removes the solvent NMP from the PAA, during both the ablation and deposition phases; this is a necessary step in generating
PI films.
PACS 41.60.Cr; 78.30.Jw; 81.15.Fg 相似文献
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Yansong Wang Yubin Shen Youwei Zhang Bin Yue 《Journal of Macromolecular Science: Physics》2013,52(4):563-571
The preparation of a new type of semi‐interpenetration network system of polyacrylic acid (PAA) hydrogel trapped with polysodium‐p‐styrenesulfonate (PSS) is presented. The structure and response properties of PAA/PSS were investigated by Fourier transform infrared (FTIR) analysis and pH and ionic intensity stimuli‐responsive measurement. The FTIR analysis proved the successful intermingling of PSS into PAA. The swelling behavior of PAA hydrogel in an alkaline environment was improved due to the addition of PSS. As the ionic concentration in solution increased, the swelling rate of PAA decreased after adding PSS. However, the swelling velocity of the pure PAA is quicker than that of the PAA/PSS samples since the PSS will enhance the entanglement of this hydrogel network and slow down the swelling velocity. Multi‐interactions between the PAA hydrogel network and trapped PSS chains, including electrostatic repulsive interaction, entanglement interaction, ionic intensity interaction, and osmotic pressure, were proposed to explain the earlier‐mentioned experimental phenomena. 相似文献