进行纳米结构加工的新兴STM技术

本文论述了新兴纳米加工技术－ＳＴＭ（ＳｃａｎｎｉｎｇＴｕｎｎｅｌｉｎｇＭｉｃｒｏｓｃｏｐｅ）的原理、实验方法、结构形成的机理和最新成果，并分析了它的发展潜力和当前需要研究的主要课题。     

STM在纳米科技中的应用几例

本文阐述了我们用超高真空ＳＴＭ在介观物理和纳米科技前沿领域做的一些探索和结果。     

石墨表面扫描隧道显微镜纳米级加工研究

利用自制的扫描隧道显微镜(STM),进行了石墨表面的纳米级加工研究.在用STM对固体材料表面进行纳米级超微加工过程中,当探针-试样间施加一高电压脉冲时,电子反馈回路将使探针急速回缩,导致实际有效电压脉冲宽度远小于所施加的电压脉冲宽度.我们专门设计了由计算机编程控制的瞬时"保持"功能,即在高电压脉冲作用过程中,使探针始终固定在原有位置,并保持原有探针-试样间距不变.因而在进行固体材料表面纳米级超微加工时,可准确地测得有效电压脉中宽度.通过在大气中对石墨表面的蚀刻研究,首次测得在电压脉冲幅值为4V时,有效脉宽阈值为(0.04±0.01)μs.     

STM2000扫描隧道显微镜

STM2000扫描隧道显微镜是英国VG公司产品。它除了带有高真空样品室以外还配有锁相放大器。因此它不仅能观察样品表面形貌像,而且还能观察到样品表面的原子结构像以及其相应的电子结构。 STM2000技术指标分辨率:2A 用VG公司提供的石墨解离表面垂直噪音:最大0.1A 漂移:<5A/分钟(包括压电蠕变) 扫描范围:10A×10A到1μm×1μm 步长:最小0.1A     

STM电压脉冲法纳米超微加工机理的研究

ＳＴＭ电压脉冲法纳米超微加工机理的研究姚王非①齐小丁②胡小唐②（天津大学分析中心①，天津大学精密仪器工程系②，天津３０）纳米制造是纳米技术的核心，尤其是微细尺寸的加工，ＳＴＭ工作时，针尖与样品间距非常小（一般小于１ｎｍ），在两者之间施加非常小的电压，...     

压电陶瓷扫描管在纳米加工中的应用

用一圆筒形压电陶瓷作三维微位移器，控制扫描隧道显微镜金属探针，利用场蒸发原理，实现了纳米加工。用Ａｕ，Ｃｕ和Ｎｉ等金属针尖在金表面制作了纳米尺寸的图案，汉字，其中组成这些图案和汉字的每个原子堆的直径约１０－４０ｎｍ，实验表现出非常好的可控性，重复性和稳定性。     

基于扫描隧道显微镜的纳米加工技术

介绍了具有原子级分辨率的扫描隧道显微镜(STM)的工作原理及其相对于传统的电子束加工所具有的技术优势,阐述了STM在纳米加工中的应用和需要解决的技术难题。     

脉冲宽度导致的石墨表面纳米结构尺度变化的STM观察

材料表面进行的纳米加工探索已经成为研究纳米尺度上的化学现象的重要途径。大量实验数据表明,利用ＳＴＭ进行的表面纳米加工过程是同时受到强电场和高电流密度的作用而诱导的局部氧化或聚合反应等。     

扫描隧道显微镜（STM）在纳米结构制造中的应用

本文简要地阐明了扫描隧道显微镜(STM)的工作原理,详细地介绍了STM 在纳米结构制造中的一些应用,包括 STM 诱导淀积和刻蚀,STM 直接刻写、电子束光刻和移动单个原子等。     

基于STM的多模式扫描探针显微镜的建立

在已有的扫描隧道显微镜（STM）基础上设计了一套集STM、 光子扫描隧道显微镜（PSTM）、近场扫描光学显微镜（NSOM）、扫描近场声学显微镜（SNAM）为一体的多模式扫描探针显微系统（SPM）。系统的4种模式可通过转换开关方便地切 换,探头的更换也很容易。利用本系统对典型样品进行了扫描成像。测试表明,系统具有良好的稳定性和超高分辨率。     

Cu－Zn－Al合金中贝氏体的扫描隧道显微镜分析

本文用扫描隧道显微镜（ＳＴＭ）在天气中研究了Ｃｕ－２７．２ｗｔ．％Ｚｎ－４．７ｗｔ．％Ａｌ合金中的贝氏体的精细结构，并与透射电镜（ＴＥＭ）及扫描电镜（ＳＥＭ）下的形态进行了比较，发现Ｃｕ－Ｚｎ－Ａｌ合金中贝氏体是由亚片条或亚单元组成，亚单元由超亚单元构成，进而为贝氏体相变机制的再认识提供了重要的实验基础，并在此基础上提出Ｃｕ－Ｚｎ－Ａｌ合金中贝氏体的形成模型。     

玉米杂交品种胚乳淀粉粒性状的扫描电镜观察

本文用扫描电镜对13种玉米杂交品种胚乳淀粉粒形态特征作了观察。结果表明:成熟的胚乳淀粉粒均呈多面体;腹白部的淀粉粒多呈近圆形;一般直径约为6.0～18.3μm。但各品种间淀粉粒的微细形态特征和大小有明显差别。因此,观察研究品种胚乳淀粉粒的形态特征,可为初步鉴别米质的优劣及杂交育种工作提供必要的参考依据。     

一种新型的STM探针

以普通的石英光纤为材料，用熔拉腐蚀复合的方法制备出nm量级的光纤探针，而后在针尖表面镀上数十nm厚的金属膜，达到导电性，使其能传导隧道电流，从而研制出一种新型的扫描隧道显微镜（STM）光纤隧道探针，在STM上取得了比较理想的实验结果。本文将光纤隧道探针与金属隧道探针作了比较，并对其性能作了分析。     

Nanomanipulation of Ligand‐Stabilized Au55 Clusters by Means of Scanning Tunneling Microscopy

We have investigated ligand‐stabilized Au₅₅ clusters by means of scanning tunneling microscopy (STM) at room temperature on highly oriented pyrolytic graphite (HOPG) and other substrates. Single clusters or groups of several clusters were transferred between sample and STM tip using conventional voltage pulses. With a new variant of voltage pulses called “field‐emission pulses”, cluster shells were partly destroyed by heating with the field‐emission current, resulting in a “hardening” of the cluster layer. HOPG substrate surfaces with most of the clusters removed exhibit “pearl chains” of clusters attached to step edges.     

激光扫描声学显微镜中透镜效应的研究

通过对激光扫描声学显微镜（ＳＬＡＭ）光学成像系统的研究,推导了ＳＬＡＭ中透镜组的相关传递函数,计算了秀镜对ＳＬＡＭ图像的空间截止频率,提出了消除透镜效应的数值计算方法,并应用了ＳＬＡＭ图像的处理中,取得了较好的效果。     

Vibration Compensation for Scanning Tunneling Microscope

The influence of vibration is already one of main obstacles for improving the nano measuring accuracy. The techniques of anti--vibration,vibration isolation and vibration compensation become an important branch in nano measuring field. Starting with the research of sensitivity to vibration of scanning tunneling microscope(STM), the theory, techniques and realization methods of nano vibration sensor based on tunnel effect are initially investigated, followed by developing the experimental devices. The experiments of the vibration detection and vibration compensation are carried out. The experimental results show that vibration sensor based on tunnel effect is characterized by high sensitivity, good frequency characteristic and the same vibratory response characteristic consistent with STM.     

Spatially Resolved STM Spectroscopy of Charge Injection at the Ladder‐Type Poly(para‐phenylene)/Au(111) Interface

The effect of the morphology on charge‐carrier injection into methyl‐substituted ladder‐type poly(para‐phenylene) (Me‐LPPP) thin films deposited on a Au(111) substrate has been studied by scanning‐tunneling‐microscope‐based spectroscopy. We find that the charge‐carrier injection barrier as well as the single‐particle bandgap, E_gsp, of the polymer show significant variations at different locations of the sample surface. Normally, we find that the values of E_gsp are larger than the optical absorption edge, the energy difference being attributed to the exciton binding energy. In some regions of the sample, however, E_gsp appears to be close to or below the optical absorption edge, pointing to the effect of aggregates within the polymer film which act as hole‐trapping centers with a depth of a few 100 meV. Density functional calculations are used to elucidate the dependence of the electronic states on the polymer packing density. Our results show that in this polymer morphological inhomogeneities strongly influence the charge carrier injection and transport properties. This points to a common behavior of materials exhibiting a tendency to form aggregates. In addition, the exciton binding energy of Me‐LPPP is determined to be approx. 0.85 eV. Moreover, the comparison between the charge‐injection energy gap and the photocurrent action spectrum indicates that the photoionization threshold is not directly related to the exciton binding energy.     

Controlling Adsorbate Electronic Structure

We have used nanocavities constructed from Mn adatoms on Ag(111) to achieve a controlled modification of the electronic structure of the Ag surface. Local tunneling spectroscopy reveals an intriguing modification of the electronic structure of a single Mn adsorbate put into these cavities. Model calculations show that the changes result from the coupling between the Mn s level and surface electronic states of the substrate, which are strongly influenced by the size and geometry of the nanocavity. The dimension and geometry of the adatom array thus provide a degree of control over the induced changes.     

微细EDM技术加工微齿轮的研究

本文通过用微细电火花（ＥＤＭ）方法加工模数为０．０６的微齿轮研究，阐述了微细ＥＤＭ方法加工微齿轮的原理、方法和关键技术。