磁控溅射参数对Al薄膜微观结构及红外特性的影响研究

利用磁控溅射法在Si(100)基片上制备了Al薄膜,采用X射线衍射、扫描电镜、扫描探针显微镜和红外光谱仪研究了基片温度、溅射功率和溅射时间对Al薄膜表面、断面形貌和红外反射率的影响。结果表明:随着基片温度的升高,Al颗粒的尺寸变大,由均匀细颗粒变为不规则形状,并逐渐熔为一个整体,断面形貌变得凹凸不平,表面粗糙度增大,红外反射率呈下降的趋势;随着溅射功率的增大,Al薄膜致密平整,表面粗糙度增大,红外反射率先增大后不变;随着溅射时间的延长,Al薄膜表面粗糙度增大,红外反射率先增大后不变。     

AFM扫描过程的模拟及针尖形状反求

纳米栅格和台阶等结构的线宽准确测量,是国内外计量领域的研究热点与难点。采用原子力显微镜(AFM)能获得上述结构的三维形貌信息,但其扫描图像却是探针针尖的形貌和被测样品表面的形貌共同作用的结果,这种作用往往导致线宽边缘测量失真。为了更加精确地获得样品的表面形貌特征,首先需要重建探针针尖形貌,进而从得到的扫描图像中尽可能地消除由探针形貌带来的失真影响。基于数学形态学的盲重建理论,利用Matlab对不同形状参数的探针针尖扫描台阶样品表面进行了仿真,评价了探针形状对扫描结果的影响,初步实现了基于真实粗糙测量表面的探针针尖形状重建。     

扫描Kelvin探针力显微镜:工作原理及在材料腐蚀研究中的应用

扫描Kelvin探针力显微镜(SKPFM)是在原子力显微镜(AFM)的基础上应用扫描Kelvin探针(SKP)技术开发的检测表征手段,它能够在获取材料表面纳米级分辨率形貌的同时,原位得到样品表面高分辨率的接触电势差分布图,为揭示腐蚀反应机理提供了崭新的思路,近年来发展迅速。本文介绍了SKPFM两种工作模式的基本原理,总结了SKPFM在应用中的问题,并讨论了SKPFM和传统扫描Kelvin探针技术(SKP)的优缺点,重点综述了SKPFM在腐蚀科学研究中的应用,最后展望了SKPFM的发展方向与应用前景。     

表面粗糙度及表面形状的测量与描述

用足够的放大倍数研究零件表面时，发现所有的固体表面都是不平的。在最小的情况下，可认为表面粗糙度是以单个的原子或分子的尺寸呈现的。例如，当我们仔细将云母样品分层时，表面就可能是以分子组成光滑表面的。而实际工程中用的准确度最高的抛光表面所呈现的粗糙度尺寸也远远大于原子的尺寸。研究表面粗糙度及表面形状，最理想的测量方法应是扫描显微镜或原子力显微镜法，它们能解决单个原子的问题。但对大多数工程实际来讲，更适合的方法是研究表面形貌。一、表面粗糙度及表面形状的测量1．接触测量法表面光度仪，其基本原理如图1所示。…     

一种宽范围扫描隧道显微镜

给出了针有表面纳米形貌检测需要而研制的一种实用型宽范围扫描隧道显微镜，扫描范围为４０×４０×１０μｍ＾３，配有一个放大倍数可调的光学显微镜帮助选择视场，可测量较大尺寸试件，实验表明，该ＳＴＭ所测图像清晰，使用方便，结构简单，适于产品化。     

用于扫描探针电子能谱仪的扫描隧道显微镜

扫描探针电子能谱学是正在发展中的一种结合了扫描隧道显微技术的电子能谱学技术,可以原位地获得固体表面的形貌和能谱信息。本文针对新研制的扫描探针电子能谱仪专门设计制作了一台采用横向隧道结结构、小巧紧凑、稳定对称的扫描隧道显微镜,可以工作在隧道区测量样品表面形貌,也可以在近场发射区测量表面背散射电子能谱。在高定向热解石墨和石墨基底上蒸镀的银膜样品的得到的原子分辨、纳米结构图像和原位电子能量损失谱表明这两种功能已完全实现。     

使用SPM的纳米级加工技术新进展

扫描探针显微镜(SPM)现在不仅用于表面微观形貌的检测，同时也用于纳米超精密加工和原子操纵，该文介绍了用STM和AFM进行纳米级加工的各种最新方法：针尖直接雕刻，针尖光刻加工，局部阳极氧化，原子沉积形成纳米点，原子去除形成沟槽微结构，多针尖加工，原子自组装形成三维结构等．使用SPM的纳米级加工对发展微型机械、纳米电子学和微机电系统具有重要意义．     

锐钛矿二氧化钛纳米线的水热制备及其表征

利用水热法制备了锐钛矿TiO2纳米线，用X射线衍射仪（XRD）、扫描电子显微镜（SEM）和原子力显微镜（AFM）对TiO2纳米线的形貌、成份进行了分析表征。在进行AFM观测时，采用一种简单易行的方法将TiO2纳米线固定在ITO玻璃衬底表面，解决了AFM扫描过程中样品不能稳定吸附在衬底上的问题。经过适当改进，该方法同样适用于其他粉末状纳米材料的原子力显微镜和扫描隧道显微镜（STM）研究。     

PDDA／Au NPs复合分子沉积膜的制备、表征和摩擦学行为

采用小分子柠檬酸钠对金纳米粒子进行包覆改性,紫外光谱分析经改性的金纳米粒子表面共振吸收峰为526iun,激光纳米粒度仪分析表明其平均粒径为8．4nm．改性后的金纳米粒子通过分子沉积技术,与聚二烯丙基二甲基胺盐酸盐（PDDA）组装,制得单层和多层PDDA／Au NPs复合纳米粒子分子沉积（MD）膜（简称PDDA／Au NPs复合MD膜）．采用原子力显微镜（AFM）研究了PDDA／Au NPs复合MD膜的表面形貌以及摩擦、磨损行为．研究结果表明：该复合膜能降低基底的摩擦力,其中以3层膜降低摩擦力的效果最显著．在氮化硅探针扫描行程达到30次后,膜表面才开始出现磨损痕迹．随着扫描次数的增多,膜表面在探针剪切力的作用下逐渐由致密变得疏松,形成颗粒堆积,使表面粗糙度增大,摩擦力、磨损深度也随之增加．通过实验还发现这种复合膜存在两种非正常磨损现象,即磨损负增长和膜的脱落现象.     

SrTiO3斜切基片上外延生长YBa2Cu3O7—δ薄膜的扫描探针显微镜研究

采用激光脉冲沉积法在钛酸锶SrTiO3（001）斜切基片上外延生长YBa2Cu3O7-δ薄膜，在大气环境下采用扫描探针显微镜对YBa2Cu3O7-δ薄膜的表面纳米形貌进行直接观察。发现YBa2Cu3O7-δ薄膜具有相对光滑的表面形貌，薄膜表面由沿SrTiO3台阶趋向外延生长的纳米台阶组成，薄膜生长模式主要以台阶媒体生长为主。     

SPM characterization of pulsed laser deposited nanocrystalline CrN hard coatings

Nanocrystalline CrN coatings, widely required for surface engineering application covering wear and corrosion resistance, need to be investigated for atomic scale morphology, surface roughness, local stiffness, phase uniformity, and homogeneity. Evolution of these properties as a function of thickness need to be studied. In this paper, we have attempted to address these issues through use of a multimode scanning probe microscope (SPM) equipped to carry out Atomic Force Microscopy (AFM) and Atomic Force Acoustic microscopy (AFAM) of Chromium nitride films (100-500 nm thick) on Si prepared under high vacuum by pulsed Laser Ablation using Nd-YAG Q-switched laser. Prior to SPM analysis, the coatings were annealed in N2 atmosphere at 700 degrees C for 30 minutes for improving crystallanity and coating substrate adhesion. The GIXRD patterns of these annealed specimens showed formation of nanocrystalline CrN. Also signature of amorphous phases was seen. The grain size was estimated to be less than 30 nm. Contact mode AFM imaging revealed a roughness value less than 50 nm. Local stiffness values were calculated from AFM force-distance curves. Imaging of frictional force and surface flaws are being investigated by Frictional Force Microscopy (FFM), resonance spectroscopy, and AFAM, respectively. The contrast in AFAM images is seen due to variation in surface elasticity in reference and CrN samples. Stiffness constant and elastic modulus were calculated for both the samples and compared.     

Effect of slurry composition on the chemical mechanical polishing of thin diamond films

Nanocrystalline diamond (NCD) thin films grown by chemical vapour deposition have an intrinsic surface roughness, which hinders the development and performance of the films’ various applications. Traditional methods of diamond polishing are not effective on NCD thin films. Films either shatter due to the combination of wafer bow and high mechanical pressures or produce uneven surfaces, which has led to the adaptation of the chemical mechanical polishing (CMP) technique for NCD films. This process is poorly understood and in need of optimisation. To compare the effect of slurry composition and pH upon polishing rates, a series of NCD thin films have been polished for three hours using a Logitech Ltd. Tribo CMP System in conjunction with a polyester/polyurethane polishing cloth and six different slurries. The reduction in surface roughness was measured hourly using an atomic force microscope. The final surface chemistry was examined using X-ray photoelectron spectroscopy and a scanning electron microscope. It was found that of all the various properties of the slurries, including pH and composition, the particle size was the determining factor for the polishing rate. The smaller particles polishing at a greater rate than the larger ones.     

Topographic measurements of supersmooth dielectric films made with a mechanical profiler and a scanning force microscope

The roughnesses of five supersmooth dielectric films of Si(3)N(4), TiO(2), HfO(2), Ta(2)O(5), and Al(2)O(3) prepared by an ion-beam-sputtering technique were measured with a commercial Talystep mechanical profiler and a sensitive Leica WYKO SPM30 scanning force microscope (SFM) to determine how much roughness the films added to the ～1-?-rms roughness fused-silica substrates on which they were deposited. In all cases the increase in roughness for the three-quarter-wave optical thickness films was a small fraction of an angstrom. SFM measurements showed that the topography of the Ta(2)O(5) and Al(2)O(3) films was less random than that of the other film materials and the substrates.     

不锈钢表面粗糙度对超高分子量聚乙烯摩擦磨损性能的影响

以超高分子量聚乙烯软骨材料为销样,316不锈钢硬骨材料为盘样,在自制的销－盘式磨损试验机上考察了不锈钢盘样表面粗糙度对超高分子量聚乙烯摩擦磨损性能的影响,并利用光学显微镜观察了摩擦副表面的形貌,结果表明,在干摩擦条件下,表面粗糙度对超高分子量聚乙烯的摩擦磨损有较大影响,存在着适合的表面粗糙度范围,使超高分子量聚乙烯摩擦系数,磨损率最小。     

Characterization of anodic SiO2 films on P-type 4H-SiC

The physical and electronic properties of 100-120-nm thick anodic silicon dioxide film grown on p-type 4H-SiC wafer and annealed at different temperatures (500, 600, 700, and 800 °C) have been investigated and reported. Chemical bonding of the films has been analyzed by Fourier transform infra red spectroscopy. Smooth and defect-free film surface has been revealed under field emission scanning electron microscope. Atomic force microscope has been used to study topography and surface roughness of the films. Electronic properties of the film have been investigated by high frequency capacitance-voltage and current-voltage measurements. As the annealing temperature increased, refractive index, dielectric constant, film density, SiC surface roughness, effective oxide charge, and leakage current density have been reduced until 700 °C. An increment of these parameters has been observed after this temperature. However, a reversed trend has been demonstrated in porosity of the film and barrier height between conduction band edge of SiO₂ and SiC.     

Modeling and measurements of atomic surface roughness

We present a geometrical model of atomic topography with which to obtain a quantitative assessment of surface roughness. A series of two- and three-dimensional atomic surface roughness equations with sufficiently realistic parameters is developed to permit quantitative comparison with scanning-tunneling microscope and atomic-force microscope (AFM) experimental results. The model is sufficiently simple that one can easily use it to interpret experimental data. Tables are provided with estimated values for two- and three-dimensional rms atomic surface roughness in pure metal crystals and ionic crystals based on the atomic surface roughness equations. We use these roughness equations to determine the roughness of cleaved muscovite mica [essentially, KAl(2)(OH)(2)Si(3)AlO(10)]; the calculated values for both two- and three-dimensional roughness are consistent with those obtained in our AFM measurements. In addition, we demonstrate both theoretically and experimentally that atomic surface roughness is never zero.     

基于图像技术的喷墨打印纸表面孔隙分析

目的利用图像技术量化纸张表面孔隙结构,并分析孔隙与纸张表面性能的关系。方法使用拉普拉斯算子和中值滤波,处理喷墨打印纸表面扫描电镜图片(SEM),提取出喷墨打印纸表面孔隙结构,对不同粒径分布的Si O2形成的涂层孔隙进行量化和对比,得到孔的个数、面积、面积方差及面积分布情况,探讨了孔面积和分布对纸张表面性能如光泽度、粗糙度、平滑度的影响。结果 Si O2粒径分布影响纸张表面孔隙的个数、面积和均匀程度,进一步影响纸张的表面性能。Si O2粒径分布越宽,形成的孔隙个数越多,面积越大,孔隙越不均匀,所得到的表面越粗糙,平滑度和光泽度也越低。结论利用图像技术可以量化涂层表面的孔隙情况,为喷墨打印纸表面孔隙及表面性能的研究提供了可以借鉴的方法。     

Mechanical improvement of hydroxyapatite by TiO<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript> nanoparticles deposition

Deposition of Ti was carried out by laser ablation onto hydroxyapatite porous discs in an Ar atmosphere. Ti nanoparticles were deposited onto HAp surface in order to modify its roughness and morphology as it is observed by scanning electron microscopy (SEM) and scanning probe microscopy (SPM). A homogeneous distribution of Ti over the disc surface was corroborated by elemental mapping. A comparison of the hydroxyapatite hardness before and after deposition was performed using SPM nanoindentation. Transmission Electron Microscopy (TEM) showed that the Ti nanoparticles obtained were covered by an oxygen shell. It is shown that surface modifications of the covered HAp by Ti result in better mechanical properties, reducing the possible damage to the HAp ceramic by friction or impacts as it often happens in meniscus, bone junctions and the inclusion of prosthesis for human treatments.     

High molecular weight polyethylene nanospheres: synthesis physical and mechanical properties

The high molecular weight (MW) polyethylene (PE) particles of particle size varied from macro to micron to nanometer were synthesized by Grignard reagent. The microscopy analysis (scanning electron microscope, SEM; transmission electron microscope, TEM; and atomic force microscope, AFM) shows the spherical shape of PE particles. The effects of particle size, varies from macro to nanometer scale on crystal structure, crystallinity (chic), glass transition temperature (Tg), melting temperature (Tm), surface roughness and mechanical properties were studied. Differential scanning calorimetry (DSC) experiments show that the nanoparticles of PE are highly crystalline (chic approximately equal 72%). The crystal length of PE nanoparticles is found to be approximately 14 A. Although the Gibbs-Thomson equation is explained the depression of melting temperature (DeltaTm) by 5 degrees C, the impervious results of Tg are still not fully understood. The low roughness value (2 A) proves the presence of "atomic-scale-chain" folding at the surface of PE nanoparticles. A novel protocol is developed, and the elastic modulus of individual nanospherical PE particles is computed from 'force-distance' mapping curves of AFM. Hemispherical tungsten (W) tip was fabricated from focused ion beam and used as an indenter to measure the mechanical properties. It is found that the nano sized PE particles have higher elastic modulus (E = 1.2-1.4 GPa) compared to the bulk or macro sized PE (E = 0.6-0.7 GPa). The results corroborate the robustness of our experiments, since, the analogous results for macro sized particles match well with the literature.     

Surface integrity of Mg-based nanocomposite produced by Abrasive Water Jet Machining (AWJM)

This paper investigates the influence of jet traverse speed on the surface integrity of 0.66?wt% Al₂O₃ nanoparticle reinforced metal matrix composite (MMC) generated by Abrasive Water Jet Machining (AWJM). Surface morphology, surface topography, and surface roughness (SR) of the AWJ surface were analyzed. The machined surfaces of the nanocomposites were examined by laser confocal microscope and field emission scanning electron microscope (FESEM). Microhardness and elasticity modulus measurement by nanoindentation testing were also performed across thickness of the samples to see depth of the zone, affected by AWJ cutting. The result reveals that extent of grooving by abrasive particle and irregularity in AWJ machined surface increases as the traverse speed increased. Similarly, the rise in value of surface roughness parameters with traverse speed was also seen. In addition, nanoindentation testing represents the lower hardness and elastic modulus due to softening occurs in AWJ surface.