Auger Electron Spectroscopy Studies Research Articles

銅によるA533B鋼の焼戻時効脆性について

The effect of copper on temper-aging embrittlement was investigated using four heats of A533B steel. After quenched and tempered, each specimen was aged at 300, 400, 500, and 600°C for various lengths of time up to 1000 hours. The Charpy impact test was carried out and several specimens were subjected to scanning electron microscopic and Auger electron spectroscopic studies.The results obtained are summarized as follows:1) A533B steel bearing 0.37% copper showed the temper-aging embrittlement which was similar, in behavior, to the temper embrittlement caused by phosphorous under the same heat treatment condition.2) The degree of the embrittlement was affected by aging temperature, aging time, and prior austenite grain size.3) After aging, the copper enrichment was found at the fracture surface by Auger electron spectroscopic study.

Combined Auger Electron Spectroscopy and Electron Impact Desorption Studies of the Interactions of Gases with Silicon Surfaces

The interactions at room temperature of O2, H2O, NO and NH3 with thermally cleaned Si(111) surfaces have been investigated using the combined Auger electron spectroscopy and electron impact desorption techniques. The Auger yields and the electron impact desorption are related to the structural models of the adsorption complexes. The ion species observed by electron bombardment are O+ ions from Si(111)–O2, H+ and O+ ions from Si(111)–H2O, and O+ ions from Si(111)–NO systems. The energy distributions of these ions, and the adsorption kinetics measurements monitored by the ion currents are presented and discussed.

Auger electron spectroscopy study of the surface composition of the lead-indium system

The Auger spectra of lead-indium alloys (4.53, 9.08, 28.63, 44.62, and 60.49 atom% lead) and of pure lead and indium were monitored in the liquid and solid states. The relative intensities of the lead 92 eV and the indium 403 eV Auger peaks were used to determine the surface composition. The peak intensity ratio proved to be a sensitive detector of the change of surface composition with respect to temperature and bulk composition. The surface layers of the alloys were richer in lead than the bulk, and the surface composition exhibits a temperature dependence similar to that predicted by the ideal monolayer model. Oxygen decreased while carbon increased the surface excess lead concentration. Ion bombardment at 300°K caused appreciable solid state diffusion. This effect was considerably reduced by lowering the temperature to 78°K; however, selective removal of Pb then took place. Auger electron spectroscopy, when coupled with suitable calibration of the peak intensities, should be an excellent technique to study the surface thermodynamics of multicomponent systems.

Auger Electron Emission Micrography and Microanalysis of Solid Surfaces

AbstractAn electron probe Auger emission microanalyzer has been constructed. The instrument is composed of an electromagnetic focussing primary probe column and a cylindrical mirror electron energy analyzer. By using this instrument, Auger electron spectroscopy studies have been carried out in the modes of both emission microanalysis and emission micrograph. The feasibility o£ this method is investigated through its application to the study of iron surface.

Auger electron spectroscopy studies of clean polycrystalline gold and of the adsorption of mercury on gold

Auger spectra of clean polycrystalline gold have been determined in a cylindrical velocity analyzer at a resolution of 0.6%. The assignment of the Auger transitions is discussed. The energy distribution curve, N(E) is obtained from the experimental d(E×N(E))/dE curve and the secondary electron background substracted in the region of the N6VV, N7VV doublet. Deconvolution of this region was performed on a Dupont curve resolver into four separate peaks and the two larger peaks assigned to the Auger transitions N7VV and N6VV. The width of each peak is ∼ 3.2 eV which compares with a value predicted from the known band structure of gold of greater than 10 eV; apparently only a part of the valence band is available for Auger emission.

Low energy electron diffraction and auger electron spectroscopy studies of the structure of adsorbed gases on solid surfaces

Low energy electron diffraction (LEED) studies of the structure of adsorbed molecules on crystal surfaces revealed that ordered surface structures predominate under most conditions of the experiments. In the absence of chemical reactions with the substrate, the degree of ordering depends on the heats of adsorption, Δ H ads, and the activation energies for surface diffusion, Δ E D∗. Since Δ H ads is usually markedly larger than Δ E D∗, small changes of substrate temperature facilitate ordering without appreciable increase in desorption rates. The surface structures of adsorbed gases that have been reported so far have been tabulated. For molecules whose size is compatible with the interatomic distance of the substrate, rules of ordering can be proposed that permit prediction of the structure of the adsorbed layer that is likely to form. These rules indicate close packing due to attractive interactions in the adsorbed layer, and that the rotational multiplicity of the substrate is likely to be maintained by the adsorbate structure. When molecules whose dimensions are larger than the substrate interatomic distance are adsorbed, the conditions that control ordering are more complex and simple rules may not be readily applicable. The surface structures of adsorbed gases have also been studied on high Miller Index substrate surfaces. These surfaces are characterized by ordered steps separated by terraces of low index surface orientation. Many gases have different ordering characteristics on stepped surfaces than on low index crystal faces due to the stronger substrate-adsorbate interactions in these surfaces. The dissociation of diatomic molecules at steps induces the formation of new types of surface structures (frequently one-dimensional) and the dehydrogenation of hydrocarbons at steps induces the formation of ordered carbonaceous surface structures that would not nucleate on low index substrate planes. So far, mostly work function changes upon adsorption gave indication of the magnitude of charge transfer upon adsorption and on forming of new surface chemical bonds. Most recently, chemical shifts of the Auger transitions of the substrate atoms and of the adsorbed molecules upon chemisorption, have been found to provide additional information on charge redistribution during adsorption.

Auger Electron Spectroscopy Studies on Surfaces of 18–8 Stainless Steel Finished Mechanically and Electrolytically

Auger Electron Spectroscopy Studies on Surfaces of 18–8 Stainless Steel Finished Mechanically and Electrolytically

Silicon Cleaning with Hydrogen Peroxide Solutions: A High Energy Electron Diffraction and Auger Electron Spectroscopy Study

HEED and Auger electron spectroscopy have been used to evaluate silicon cleaning by sequential immersions in basic and acidic peroxide solutions. It was determined that an oxide film 13–15Aå thick was left after the cleaning. This film contained boron at a surface concentration estimated at 1013–1014 B/cm2. The carbide contamination that results upon heating to 800°C in ultra‐high vacuum was dramatically reduced when compared to wafers cleaned with other techniques. Wafers cleaned with the same process except for a final HF etch had no detectable boron in the surface oxide, formed relatively large amounts of surface silicon carbide at 800°C, and suffered extensive surface roughening with 1100°C heating in vacuum. The protective mechanism of the peroxide cleaning is thought to be due to formation of a thin nearly carbon free oxide layer that volatilizes when the wafers are heated in ultrahigh vacuum. It is recommended that experiments requiring a solvent type cleaning and the heating of Si in ultrahigh vacuum should use this cleaning method.

Electron Emission Studies from GaSe Surfaces

Photoelectric emission, LEED, and Auger electron spectroscopy studies have been carried out on GaSe single crystals cleaved in ultrahigh vacuum. The LEED measurements indicate the two-dimensional periodicity of the surface atoms to be the same as that of the bulk. The photoelectric threshold occurs at 5.4 eV, and the energy distribution of photoelectrons locates two maxima, separated by 1.3 eV, in the valence band density of states. These results are discussed in terms of the calculated band structure. A good cleavage face is found to be extremely inert to chemisorbed contamination, but poor cleavages are more reactive, and adsorption causes a low-energy peak in the energy distribution curves.

Auger-Electron Spectroscopic Studies of the Surfaces of 18-8 Stainless Steel Electropolished or Abraded by Emery Papers

The surfaces of 18-8 stainless steel electropolished or abraded by emery papers have been examined by means of an Auger electron spectrometer. The main results obtained are as follows ;(1) For the electropolished surface and the abraded one, peaks from chrome and nickel are not observed until the surfaces are sputtered with argon ions. The peak heights of carbon and oxygen are decreased, and those of iron, chrome and nickel are increased by ion bombardment.(2) Residuals of electrolytes are observed on the electropolished surface, but abrasives (mainly Al2O3) are not detectable on the abraded one.(3) The results obtained after successive ion bombardment show that the superficial region of the electropolished surface includes much amount of elemental oxygen than the region of the abraded one.

Combined LEED and Auger electron spectroscopy studies of Si, Ge, GaAs, and InSb surfaces: J T Grant and T W Haas, J Vac Sci Technol, 8 (1), Jan/Feb 1971, 94–97.

Combined LEED and Auger electron spectroscopy studies of Si, Ge, GaAs, and InSb surfaces: J T Grant and T W Haas, J Vac Sci Technol, 8 (1), Jan/Feb 1971, 94–97.

Degradation and passivation of light emitting diodes : R. L. Hartman, M. Kuhn and B. Schwartz, Proc. IEEE Reliab. Phys. Symp., Las Vegas, U.S.A. 31 March–2 April (1971)

An extensive Auger electron spectroscopy study of the aluminum-aluminum oxide interface is presented, with the aim of identifying the behaviour of the contact zone between bulk metal and bulk oxide. Restored oxygen KLL and aluminum LVV spectra have been derived and analysed as a function of the depth of a thick aluminum sample evaporated onto an aluminum oxide crystal. The capability of the Auger electron spectroscopy to derive rather unique information on the nature of the contact zone is used to infer that the metal and oxide form small isles or domains in the interface region, so that the transition from the metal to the oxide is not characterized by a sharp surface.

A High-Resolution Scanning Microscope for Surface Studies

There are a growing number of applications for high brightness electron optical systems which operate in non-contaminating “clean” residual gas atmospheres. These criteria are especially important if one wishes to look at, and characterize, surfaces for the purpose of following their behavior under rigorously-controlled conditions. Besides the obvious improvements to be gained in resolution and longer exposure to the electron beam, scanning electron microscopy can now be combined with other powerful techniques. These techniques include low energy electron diffraction (LEED), Auger electron spectroscopy (AES) and field emission retarding potential (FERP) studies of surface work functions.At one end of the electron optical column shown in Figure 1, which is only 20 cm long from source to specimen, a field emitting tungsten tip is used as the electron source, while at the other end of the column a four grid LEED/AES system has been affixed to the objective lens housing. The remainder of the column consists of a cylindrical magnetic lens, stigmator, and scanning coils. The residual gas pressure in the column during operation is <10-9 torr.

Embrittlement in low-carbon steels due to manganese

Martensitic stainless steels find extensive applications due to their optimum combination of strength, hardness and wear-resistance in tempered condition. However, this class of steels is susceptible to embrittlement during tempering if it is carried out in a specific temperature range resulting in significant reduction in toughness. Embrittlement of as-normalised AISI 410 martensitic stainless steel, subjected to tempering treatment in the temperature range of 673–923 K was studied using Charpy impact tests followed by metallurgical investigations using field emission scanning electron and transmission electron microscopes. Carbides precipitated during tempering were extracted by electrochemical dissolution of the matrix and identified by X-ray diffraction. Studies indicated that temper embrittlement is highest when the steel is tempered at 823 K. Mostly iron rich carbides are present in the steel subjected to tempering at low temperatures of around 723 K, whereas chromium rich carbides (M23C6) dominate precipitation at high temperature tempering. The range 773–823 K is the transition temperature range for the precipitates, with both Fe2C and M23C6 types of carbides coexisting in the material. The nucleation of Fe2C within the martensite lath, during low temperature tempering, has a definite role in the embrittlement of this steel. Embrittlement is not observed at high temperature tempering because of precipitation of M23C6 carbides, instead of Fe2C, preferentially along the lath and prior austenite boundaries. Segregation of S and P, which is widely reported as one of the causes for temper embrittlement, could not be detected in the material even through Auger electron spectroscopy studies.

Some properties of molybdenite cleavage surfaces

Low energy electron diffraction, Auger electron spectroscopy and photoemission studies have been carried out on surfaces of molybdenite prepared by cleavage. Surfaces cleaved in ultra high vacuum are extremely inert. There is some evidence that surfaces containing adsorbed oxygen have a weak affinity for water vapour and the significance of the result for some of the mechanical properties of MoS2 is discussed. Low energy electron diffraction measurements are consistent with a surface structure not differing greatly from that of the bulk, and the energy analysis of back scattered electrons confirms the existence of two valence bands in MoS2.

Auger Electron Spectroscopy: Metallurgical Applications

A relatively new tool in the field of metallurgy, namely Auger electron spectroscopy, has several potentially valuable uses for metallurgists. Areas of interest in which Auger electron spectroscopy studies are useful are corrosion, alloy formation, nucleation, diffusion, catalysis, epitaxy, thin film growth, and fractography. The actual experimental methods associated with the use of this technique are discussed in some detail. And where they are available, specific examples are given to illustrate usages in the above areas.

Auger electron spectroscopy of Si

Auger electron spectroscopy studies of Si have been carried out on Si (111)2 × 1, Si(111) 7 × 7, Si (111)-Fe, Si (111)-Cu, Si (111)-Au, and SiC. Identification of the Auger transitions from clean Si surfaces is made, and it is found that some may involve multiple ionization. Chemical effects such as shifts in the energy of the main Si Auger peak have been observed due to oxidation or combination with carbon in SiC.

Auger Electron Spectroscopy Study of Oxygen Adsorption on W(110)

Quantitative oxygen coverage as a function of oxygen exposure has been determined in an Auger electron spectroscopy study of oxygen adsorption on W(110). The oxygen Auger peak of the secondary electron energy distribution was resolved from the background, and the area of the peak was taken as proportional to the oxygen coverage. The initial slope of the coverage vs exposure curve provided a value of 0.23 ± 0.05 for the initial sticking coefficient. Comparison of the results with other studies is presented.