共查询到18条相似文献,搜索用时 171 毫秒
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利用扫描探针显微镜(SPM)的导电探针在PMMA薄膜表面μm/nm尺度下通过摩擦方式产生了电荷,并用静电力显微镜(EFM)对生成的电荷进行了观察。讨论了生成电荷的极性、数量、区域大小与摩擦过程中探针加工速度、所加电压大小及正负之间的关系:产生电荷的极性与摩擦过程中针尖所加电压的正负保持一致,且所加电压越大,产生电荷的区域和面积越大。但相同情况下,PMMA表面出现的正电荷区域和数量要多于负电荷;针尖带电摩擦时,摩擦速度越快,产生电荷的数量和区域也随之减小。为探索PMMA表面电荷生成规律及生成机理提供了一种新的途径。 相似文献
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在电场力显微镜(EFM)下利用不同金属镀层微探针,在微纳米尺度下对聚酰亚胺薄膜的表面电荷生成特性进行研究。采用电场力显微镜导电探针在聚酰亚胺薄膜表面注入电荷,并对微纳米区域产生的电荷进行表征,结果表明不同金属镀层的微探针对聚酰亚胺薄膜上电荷注入效果不同。铂铱合金镀层具有比钴铬合金镀层更高的功函数fm,因此前者在金属-电介质接触中产生更大肖特基势垒,进而降低了电荷的注入程度。该研究为微纳米尺度下探索聚合物绝缘材料表面电荷生成、发展机理提供了一个新的研究方法和途径。 相似文献
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聚酰亚胺液晶垂直取向膜的表面取向分析 总被引:3,自引:3,他引:0
采用均苯四甲酸二酐(PMDA)、4,4′-二胺基二苯甲烷(MDA)以及侧基含联苯和己基的二胺(TBCA)三元共聚制备了聚酰亚胺垂直取向剂,摩擦前后得到相同的垂直取向效果,探讨了侧链二胺TBCA的含量对聚酰亚胺取向膜垂直取向性能的影响,采用衰减全反射红外光谱(ATR-FTIR)对摩擦前后聚酰亚胺膜表面侧链的相对含量进行了对比,并运用原子力显微镜(AFM)考察了表面细微沟纹对液晶分子取向的影响。结果表明,在取向膜未经摩擦没有产生表面沟纹的情况下液晶分子也能取向,并且这类取向膜表面侧链的含量与摩擦后的含量相当。 相似文献
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扫描探针显微镜(SPM)作为一种广泛应用的表面表征工具,不仅可以表征三维形貌,还能定量地研究表面的粗糙度、孔径大小和分布及颗粒尺寸,在许多学科均可发挥作用.以纳米材料为主要研究对象,综述了国外最新的几种扫描探针显微表征技术,包括扫描隧道显微镜(STM)、原子力显微镜(AFM)和近场扫描光学显微镜(SNOM)等方法,展示了这几种技术在纳米材料的结构和性能方面的应用. 相似文献
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应用SPM技术开展纳米切削加工 总被引:3,自引:1,他引:2
纳米科技发展和应用的一个重要问题是:解决纳米尺度上的操作,加工和控制,本文针对目前传统机械加工方法在纳米量级加工能力上存在的不足,以及利用SPM探针针尖进行纳米加工在工程应用中所面临的技术问题,提出应用SPM原理和技术,直接使用金刚石丸具进行材料的纳米量级去除加工方法。文中应用该方法对石墨以及金属材料进行了微去除加工实验,研究和考察了纳米切削加工时,切削形成和良好加工表面的形成,结果显示,这是一种好的纳米加工方法,既可作为材料加工过程的研究手段,又具有良好的实际应用前景。 相似文献
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综述了扫描探针显微镜(SPM)系统中显微镜主体部分的各种结构方式,分析其优缺点,对新型SPM的设计提供了参考。 相似文献
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为了解决传统扫描探针显微镜(SPM)控制器中参数难以设定的难题,提出了一种SPM的PI参数自整定控制器的设计,并给出了控制器的硬件结构和软件设计.该控制器基于DSP,通过引入扫描式参数优化算法来实现.结果表明,该控制器能自动完成PI参数的测算,并给出最优的PI参数,提高了SPM扫描图像的质量. 相似文献
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M. Hamasaki 《Solid-state electronics》1983,26(4):299-303
The effects of electron-beam evaporation of Al on fast surface states, oxide charges and generation lifetime in MOS capacitors were studied. Fast surface states were increased when the thickness of the oxide was reduced to less than 400 Å. Negative charges were induced near the A1/SiO2 interface. Both negative charges and fast surface states were reduced by using higher deposition temperatures, even though deposition temperatures were lower than post-metallization-annealing temperatures.Generation centers were also induced by electron beam evaporation. However, such generation centers were removed completely by the cleaning of furnace tubes with HCl. 相似文献
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By using time-resolved electric field induced optical second harmonic generation (TR-EFISHG) measurement, we studied the rectifying property of organic double-layer diodes with a structure of indium-tin-oxide/polyimide/6,13-Bis(triisopropylsilylethynyl)-pentacene/gold (ITO/PI/TIPS-pentacene/Au). Upon application of a step voltage to the diodes, the TR-EFISHG probed the electric field changes induced in the TIPS-pentacene layer by hole injection from the ITO electrode, followed by the hole accumulation at the PI/TIPS-pentacene interface. Consequently, the electric field distributions in the diodes before and after the carrier injection were traced with accumulated charges at the PI/TIPS-pentacene interface, depending on the DC biasing applied to the diodes. Analyzing the carrier behavior in ITO/PI/TIPS-pentacene/Au on the basis of a Maxwell–Wagner model, we discussed the rectifying property of the diodes in terms of DC biasing effect, i.e., threshold-voltage shift, and concluded that space charge limited current process that flows across the PI layer governs the rectification of the diodes. Using the TR-EFISHG measurement is an effective way to study the rectifying property of organic double-layer diodes. 相似文献
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A finite-difference implementation of the beam propagation method (BPM) is used to solve the paraxial, scalar wave equation with a nonlinear source term. A transparent boundary condition capable of handling asymmetric modes is incorporated in the finite-difference algorithm. This nonlinear BPM is used to model the generation and propagation of second harmonic light in an optical fiber which has been prepared for second harmonic generation (SHG) by the formation of a χ(2) grating. This method can be used to predict the guided mode in which the generated second harmonic light propagates based on the modes of the writing (fundamental and second harmonic) and reading (fundamental only) light. The effects of self-phase modulation (SPM) and cross-phase modulation (XPM) are included in the model 相似文献