Scanning Techniques

The ability to control the position of a fine tip in order to scan surfaces with subatomic resolution has brought scanning probe microscopies to the forefront in surface imaging techniques. We discuss the two primary techniques, scanning tunneling microscopy (STM) and atomic force microscopy (AFM) the interested reader is referred to comprehensive reviews [9, 17, 18]. 

The brief history, operation principle, and applications of the above-mentioned techniques are described in this chapter. There are several other measuring techniques, such as the fluorometry technique. Scanning Acoustic Microscopy, Laser Doppler Vibrometer, and Time-of-flight Secondary Ion Mass Spectroscopy, which are successfully applied in micro/nanotribology, are introduced in this chapter, too. 

By scanning the laser beam in the x and y directions, the LDV technique can be extended to full area measurement and display. This technique scans an area on a point-by-... 

The late 1980s saw the introduction into electrochemistry of a major new technique, scanning tunnelling microscopy (STM), which allows real-space (atomic) imaging of the structural and electronic properties of both bare and adsorbate-covered surfaces. The technique had originally been exploited at the gas/so id interface, but it was later realised that it could be employed in liquids. As a result, it has rapidly found application in electrochemistry. 

Another variation of the FRAP technique scans the laser in one dimension across the cell producing a line-scan profile of fluorescence intensity (14). For a round cell whose surface is evenly labeled with a fluorescently conjugated antibody, a line scan typically produces a profile with two peaks of fluorescence, since the laser beam is illuminating more fluorophores at the edges... 

Werner-Linde, Y., Pallon, J., and Forslind, B., Physiologically important trace elements of paralesional psoriatic skin. Quantitative analysis of distributions using scanning proton probe technique, Scanning Microsc., 12, 599, 1998. 

The composites as well as the nanowires were characterized by several techniques. Scanning electron microscopy (SEM) images and energy dispersive analysis of x-rays (EDAX) were obtained with a Leica S-440I microscope fitted with a Link ISIS spectrometer. Infrared (IR) spectra were recorded on small pieces of the samples embedded in KBr pellets using a Broker FT-IR spectrometer. DSC was carried out on the samples ( 7 mg) with a scanning rate of 20 K min-1 between 120 and 260 °C using a Mettler-Toledo DSC. 

Energy-dispersive X-ray microanalysis Surface analytical techniques Scanning near-field optical microscopy Scanning thermal microscopy Atomic force microscopy X-ray photoelectron spectroscopy... 

SURFACE ANALYTICAL TECHNIQUES Scanning Probe Microscopies... 

Spectroscopic techniques Scanning Tunneling Spectroscopy (STS) Frequency-Distance Curves Force-Distance Curves Phase- Distance Curves Full-resonance Spectroscopy Adhesion Force Spectroscopy Amplitude-Distance Curves I(z) Spectroscopy I(v) Spectroscopy... 

Electrochemical detectors were reported used by 21% of the respondents to the detector survey (47). Electron transfer processes offer highly sensitive and selective methods for detection of solutes. Various techniques have been devised for this measurement process, with the most popular being based on the application of a fixed potential to a solid electrode. Potential pulse techniques, scanning techniques, and multiple electrode techniques have all been employed and can offer certain advantages. Two excellent reviews of electrochemical detection in flowing streams have appeared (59,60), as well as a comprehensive chapter in a series on liquid chromatography (61). 

In the introductory part of this survey, it has been stated that modern mass spectrometry is no more one single spectrometric method. In several chapters some of the most important actual techniques and possible trends in modem mass spectrometry have been discussed. The complexity of the numerous ionization techniques, scan modes and different mass spectrometer types — at least at first sight — may create a feeling of obscure diffuseness. However, this complexity of performing mass spectrometry clearly demonstrates what a mass spectrometer really can be, namely a complete laboratory in itself including synthetic and analytical parts. 

In order to supplement micro-mechanical investigations and advance knowledge of the fracture process, micro-mechanical measurements in the deformation zone are required to determine local stresses and strains. In RTFs craze zones can develop that are important microscopic features around a crack tip governing strength behavior. Plastics fracture is preceded by the formation of a craze zone that is a wedge shaped region spanned by oriented micro-fibrils. Methods of craze zone measurements include optical emission spectroscopy, diffraction techniques, scanning electron microscope, and transmission electron microscopy. 

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