基于超高密度信息存储薄膜制备的研究进展

信息技术的发展要求存储器件必须具备超高存储密度、超快的存取速率.存储介质是高密度信息存储研究中的基本问题,目前几乎所有的超高密度存储技术都是在薄膜介质上实现的.薄膜的性质除依赖于存储介质材料外还依赖于薄膜的制备技术.从存储介质薄膜的制备角度介绍了超高密度信息存储的研究进展.     

基于STM/AFM技术的信息存储材料研究现状及进展

信息技术的发展要求存储器件必须具备超高存储密度、超快的存取速率，因而能在纳米尺度上实现信息存储功能的新型超高密度信息存储材料已经成为信息技术领域的研究热点。简要地介绍了近年来利用扫描隧道显微镜／原子力显微镜（STM／AFM）实现信息写入的纳米信息存储材料的研究进展，并进一步列举了尚待解决的问题。     

有机功能薄膜的超高密度信息存储

超高密度信息存储研究是纳米电子学的重要研究领域,有机功能薄膜以其独特的性质有可能成为超高密度信息存储介质之一。利用ＳＴＭ研究了Ｎ,Ｎ－二甲基－Ｎ－（３－硝基苯叉）－对苯二胺（ＤＭＮＢＰＤＡ）有机薄膜的存储特性。高分辨扫描电子显微镜的结果表明,在扫描过程中ＳＴＭ对ＤＭＮＢＰＤＡ薄膜表面进行了二次加工,显微Ｒａｍａｎ谱表明在加工区依然存在着ＤＭＮＢＰＤＡ薄膜,并用原子力显微镜表征了加工区薄膜的表面形貌     

基于SPM的纳米计量中若干重要问题

扫描探针显微镜(SPM)由于具有纳米甚至原子量级的分辨率,20多年来已引起各个领域科学家们的广泛兴趣。在精密工程领域,它作为一种极具前途的纳米计量工具,已在许多国家受到了广泛的重视,如美国NIST,德国PTB和英国NPL等都相继开展了基于SPM的纳米计量技术研究。但作为纳米级的计量分析仪器,不仅要有高分辨率,更要有纳米级甚至更高的精度。     

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．     

我科学家在纳米信息存储材料领域再获突破

我国科研人员在Rotaxane类分子的结构与电导转变及其在超高密度信息存储中的应用研究方面再获突破。在此前工作的基础上成功地在H2 Rotaxane分子薄膜中实现了可逆的电导变化和可擦除、稳定、重复的近于单分子尺度的纳米级存储。这是目前为止该类分子结构与电导转变的最直接证据，对Rotaxane类分子在分子电子学中的进一步应用具有重要意义。     

超高密度信息存储薄膜研究最新进展

信息技术的发展要求存储器件必须具备超高存储密度,超快的存取速率及长的存储寿命。目前前广泛应用的磁存储和光存储介质正在接近其物理极限。本文简要地综述了近来该方面的研究进展。     

超大容量纳米级信息存储材料问世

法国和瑞士科学家开发出一种名为“自动组合结构”的材料制造技术，进而制成新型超大容量的纳米级信息存储材料，每平方厘米的这种材料可存储的信息达到4万亿比特。     

基于SPM的超媒体人机接口

当利用扫描隧道显微镜(SPM)作为一种纳米操作工具时,由于其缺乏实时的传感器信息反馈,而大大阻碍了它的广泛应用．利用超媒体人机交互接口可以解决这个问题．在纳米操作过程中,超媒体接口不但可以为操作者提供可实时更新的仿真操作场景,还可以通过力反馈手柄让操作者实时地感受到探针受到的三维纳米操作力．除此之外,操作者还可以通过该手柄直接控制探针的三维运动．最后在聚碳酸酯上进行了超媒体人机接口的纳米刻画实验．实验结果验证了该系统的有效性和效率．     

纳米半导体薄膜制备技术

采用分类综述的方法,介绍了纳米半导体薄膜制备技术的研究进展,并对各种制备技术的特点进行了评价。     

Study of thin film multilayers using X-ray reflectivity and scanning probe microscopy

We have presented new schemes to analyse grazing incidence specular X-ray reflectivity data to obtain structural and chemical information of thin films. Analysis of specular reflectivity data gives information along the depth of the film, whereas, analysis of non-specular data reveals the structural information across the film surface and interfaces. The schemes proposed are based on the Born approximation and the distorted wave born approximation (DWBA). Surface structural parameters such as, height–height correlation and roughness exponent of the film obtained from the analysis of X-ray reflectivity was compared with results obtained from atomic force microscopy     

Active nanocharacterization of nanofunctional materials by scanning tunneling microscopy

Abstract

Recent developments in the application of scanning tunneling microscopy (STM) to nanofabrication and nanocharacterization are reviewed. The main focus of this paper is to outline techniques for depositing and manipulating nanometer-scale structures using STM tips. Firstly, the transfer of STM tip material through the application of voltage pulses is introduced. The highly reproducible fabrication of metallic silver nanodots and nanowires is discussed. The mechanism is thought to be spontaneous point-contact formation caused by field-enhanced diffusion to the apex of the tip. Transfer through the application of z-direction pulses is also introduced. Sub-nanometer displacement pulses along the z-direction form point contacts that can be used for reproducible nanodot deposition. Next, the discovery of the STM structural manipulation of surface phases is discussed. It has been demonstrated that superstructures on Si(001) surfaces can be reverse-manipulated by controlling the injected carriers. Finally, the fabrication of an atomic-scale one-dimensional quantum confinement system by single-atom deposition using a controlled point contact is presented. Because of its combined nanofabrication and nanocharacterization capabilities, STM is a powerful tool for exploring the nanotechnology and nanoscience fields.     

Active nanocharacterization of nanofunctional materials by scanning tunneling microscopy

Recent developments in the application of scanning tunneling microscopy (STM) to nanofabrication and nanocharacterization are reviewed. The main focus of this paper is to outline techniques for depositing and manipulating nanometer-scale structures using STM tips. Firstly, the transfer of STM tip material through the application of voltage pulses is introduced. The highly reproducible fabrication of metallic silver nanodots and nanowires is discussed. The mechanism is thought to be spontaneous point-contact formation caused by field-enhanced diffusion to the apex of the tip. Transfer through the application of z-direction pulses is also introduced. Sub-nanometer displacement pulses along the z-direction form point contacts that can be used for reproducible nanodot deposition. Next, the discovery of the STM structural manipulation of surface phases is discussed. It has been demonstrated that superstructures on Si(001) surfaces can be reverse-manipulated by controlling the injected carriers. Finally, the fabrication of an atomic-scale one-dimensional quantum confinement system by single-atom deposition using a controlled point contact is presented. Because of its combined nanofabrication and nanocharacterization capabilities, STM is a powerful tool for exploring the nanotechnology and nanoscience fields.     

Dynamic probe of ZnTe(110) surface by scanning tunneling microscopy

The reconstructed surface structure of the II–VI semiconductor ZnTe (110), which is a promising material in the research field of semiconductor spintronics, was studied by scanning tunneling microscopy/spectroscopy (STM/STS). First, the surface states formed by reconstruction by the charge transfer of dangling bond electrons from cationic Zn to anionic Te atoms, which are similar to those of IV and III–V semiconductors, were confirmed in real space. Secondly, oscillation in tunneling current between binary states, which is considered to reflect a conformational change in the topmost Zn–Te structure between the reconstructed and bulk-like ideal structures, was directly observed by STM. Third, using the technique of charge injection, a surface atomic structure was successfully fabricated, suggesting the possibility of atomic-scale manipulation of this widely applicable surface of ZnTe.     

Dynamic probe of ZnTe(110) surface by scanning tunneling microscopy

Abstract

The reconstructed surface structure of the II–VI semiconductor ZnTe (110), which is a promising material in the research field of semiconductor spintronics, was studied by scanning tunneling microscopy/spectroscopy (STM/STS). First, the surface states formed by reconstruction by the charge transfer of dangling bond electrons from cationic Zn to anionic Te atoms, which are similar to those of IV and III–V semiconductors, were confirmed in real space. Secondly, oscillation in tunneling current between binary states, which is considered to reflect a conformational change in the topmost Zn–Te structure between the reconstructed and bulk-like ideal structures, was directly observed by STM. Third, using the technique of charge injection, a surface atomic structure was successfully fabricated, suggesting the possibility of atomic-scale manipulation of this widely applicable surface of ZnTe.     

激光扫描共聚焦显微镜在荧光原位杂交中的应用

简要介绍激光扫描共聚焦显微镜在荧光原位杂交中的应用方法及其优越性。     

Surface analysis algorithms for scanning probe microscopy

A single data set in scanning probe microscopy is large, typically in the megabyte range. As interpretation is accomplished by displaying the data in image form for visualization, image processing methods are used to both convert to visual images and to modify the images in order to clarify features of interest. Although an impressive number of image-processing algorithms are available on most commercial probe microscopes, many potentially very interesting ones are not. In addition, the special character of scanning probe data sets calls for development of new algorithms specially suited to this kind of problem. The work here analyzes images produced using atomic force microscope data sets. Algorithms are shown and discussed using images of oxide surfaces. The following algorithms are applied: tilt correction, scattering noise removal, surface smoothing, surface compression, probability density function analysis, correlation, and power spectrum analysis. Such algorithms and others serve to remove spurious surface spikes, enhance visualization of long-range surface features in the presence of short-range surface variations, remove line-to-line scanning artifacts, etc.     

A review of advanced scanning probe microscope analysis of functional films and semiconductor devices

This paper gives an overview of established methods and new developments in the field of Scanning Probe Microscopy (SPM) of functional films and semiconductor devices. It focuses on both, SPM analyses of passive structures and devices in operation. The contribution includes techniques such as Scanning Capacitance Microscopy (SCM) and Scanning Spreading Resistance Microscopy (SSRM) for implant mapping, Conductive AFM (C-AFM) for thin dielectrics analysis and Kelvin Probe Force Microscopy (KPFM) to study the potential distribution across active electronic devices. Finally combinations of different SPM-based techniques are described and future challenges for SPM-based techniques are discussed.     

Antibacterial action of lipidic nanoemulsions using atomic force microscopy and scanning electron microscopy on Escherichia coli

The present study demonstrates the mechanism of bactericidal effect rendered by cationic and non-cationic lipidic emulsions using atomic force microscopy (AFM) and scanning electron microscopy. The AFM images of treated Escherichia coli cells indicated the conformational alteration from rod-shaped bacteria to a fluid-flattened structure with the presence of pore in the centre of bacterium, indicating the cell lysis. Root mean square roughness increased substantially due to exposure of underlying rugose peptidoglycan layer when treated with non-cationized lipidic nanoemulsions (NCLE). The cationised-lipidic-emulsion (CLE) treated E. coli cells frequently showed division septa along the length of E. coli which was not visible in non-cationised treated bacterial cells. The enhanced adhesion between CLE and negatively charged bacteria leads to lesser time required to kill the bacteria as compared to NCLE.     

Developments and perspectives of scanning probe microscopy (SPM) on organic materials systems

In this paper recent developments in scanning probe microscopy ( SPM ) on organic materials are reviewed with selected examples. Presented subjects include instrumentation and particularities in connection with SPM imaging on soft organic materials. Exemplary cases of structure-properties investigations with SPM in organic materials science including amorphous polymers, polymer crystal growth effects, interface structure and stability, spinodal decomposition effects, copolymer and liquid crystal (LC) nanophase separation, LC phase transitions on a molecular scale, molecular manipulation as well as structure and properties of other organic materials are presented. Naturally, this paper cannot review all papers published about SPM on organic materials. Rather, main principles and problems as well as the strategy of probe microscopy on organic materials is elucidated with selected examples. SPM is shown to be an effective and forceful organic materials analytic tool for the materials scientist.