Auger electron spectroscopy contacts

The most widely used techniques for surface analysis are Auger electron spectroscopy (AES), x-ray photoelectron spectroscopy (XPS), secondary ion mass spectroscopy (SIMS), Raman and infrared spectroscopy, and contact angle measurement. Some of these techniques have the ability to determine the composition of the outermost atomic layers, although each technique possesses its own special advantages and disadvantages. 

As mentioned previously, this can be attributed in part to the lack of structure-sensitive techniques that can operate in the presence of a condensed phase. Ultrahigh-vacuum (UHV) surface spectroscopic techniques such as low-energy electron diffraction (LEED), Auger electron spectroscopy (AES), and others have been applied to the study of electrochemical interfaces, and a wealth of information has emerged from these ex situ studies on well-defined electrode surfaces.15"17 However, the fact that these techniques require the use of UHV precludes their use for in situ studies of the electrode/solution interface. In addition, transfer of the electrode from the electrolytic medium into UHV introduces the very serious question of whether the nature of the surface examined ex situ has the same structure as the surface in contact with the electrolyte and under potential control. Furthermore, any information on the solution side of the interface is, of necessity, lost. 

The experiments were performed in stainless steel UHV chambers which were equipped with the instrumentation necessary to perform Auger Electron Spectroscopy (AES), X-ray Photoelectron Spectroscopy (XPS), UV Photoelectron Spectroscopy (UPS), Low Energy Electron Diffraction (LEED), work function measurements (A( )), High Resolution Electron Energy Loss Spectroscopy (HREELS), and Temperature Programmed Desorption (TPD). The Au(lll) crystal was heated resist vely and cooled by direct contact of the crystal mounting block with a liquid nitrogen reservoir. The temperature of the Au(lll) crystal was monitored directly by means of a... 

XRF = X-ray fluorescence spectroscopy, XPS = X-ray photoelectron spectroscopy, AES = Auger electron spectroscopy, XANES = X-ray absorption near edge spectroscopy, RAIR = Reflectance-absorbance infrared spectroscopy, EXAFS = X-ray absorption fine-structure spectroscopy, ECR = Electric contact resistance, NMR = Nuclear magnetic resonance spectroscopy, IPS = Imaging photoelectron spectromicroscopy. 

While Auger electron spectroscopy and X-ray photoelectron spectroscopy can give elemental and organic structual information, respectively, they have limitations in the amount of material they can detect. For example, where polymers are in sliding, rolling or rubbing contact with metal or alloys wear to the metal as well as... 

Chromium and aluminum are resistant to atmospheric corrosion individually but when porous chromium in intimate contact with aluminum is exposed to high humidities substantial corrosion occurs at the interface of the two materials. This is illustrated by the roughening data of Figure 4. Auger electron spectroscopy shows 0, S,... 

Commonly used spectroscopic or analytical techniques for characterizing surfaces and coating layers on porous silicon are Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy, energy dispersive X-ray spectrometry, fluorescence spectroscopy, UV-Vis absorption/reflectance spectroscopy, thin film optical interference spectroscopy, impedance spectroscopy, optical microscopy, scanning electron microscopy, transmission electron microscopy, atomic force microscopy, ellipsometry, nitrogen adsorption/desorp-tion analysis, and water contact angle. 

If we assume that the development of a standard state, i.e. ideal metal-vacuum interface, was in fact the key to the advancements in metallic contact analysis we should also expect that this will also be the case in the polymer, or solid organic, friction or adhesion analysis. The consequence is that polymer surface characterization under various environments becomes the most important issue at hand. The achievement of the standard surface state in polymer or solid organic system will be most difficult due to the relatively weak intermolecular bonding forces and the normal existance of a wide range of impurities within the material itself. Ambient vacuum conditions are required for most of the physics oriented surface characterization techniques, e.g. LEED, FIM, Auger electron spectroscopy and under these conditions the surface can be modified by... 

The surface structures are schematically summarized in Figure 7.12 [8]. There are various methods to characterize these surface structures, for example, ultravacuum techniques such as Auger electron spectroscopy and X-ray photoelectron spectroscopy, Raman spectroscopy and infrar spectroscopy, contact angle and wettability, scanning tunneling microscopy, and thermal desorption mass spectrometry. 

Since electron spectroscopy reached high precision, that is since the birth and development of ESCA (as described in [5]), the kinetic energy of electrons ejected from atoms can be directly measured. X-ray photoelectron spectroscopy (XPS) competes with X-ray spectroscopy to give electron binding energies. The work function of the electron spectrometer with which the test sample is in contact needs to be known. At present a reference value of a metal level, usually Au 4f7/2 (taken as 84.00 eV) is used. This technique is preferred especially for low-energy levels since X-ray transition measurements suffer from the addition of two experimental errors. Other techniques are also used such as isochromats (see [14]) or appearance potential observations, and Auger electron spectroscopy (AES) but this involves three levels. 

The segregation of K to the surface has been demonstrated by chemisorption measurements [207, 220], by scanning Auger electron spectroscopy [52, 209-211], and by X-ray photoelectron spectroscopy [208]. Chemisorption measurements [207] and spectroscopic studies using a Fe film in a microreactor [609] have shown that K is in close contact with Fe on the active surface. 

Brainard, W.A. Buckley, D.H. "Adhesion and Friction of PTFE in Contact With Metals as Studied by Auger Spectroscopy, Field Ion and Scanning Electron Microscopy," WEAR, 26, pp. 75-93,... 

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