bluuebunny/crossref_metadata_2025_split huggingface dataset:
Compositional changes of ZnSe during implantation measured by SIMS and AES
Authors: Haberland D. , Krabel B. , Nelkowski H. , Schlaak W. 
Published: May 2005

AbstractUsing a specially designed system it is possible to observe the compositional changes of a surface during implantation. The results of implantation with Ag, Cl, Na into ZnSe will be presented. From the measured intensity of the secondary ions produced by ion implantation into the compound semiconductor ZnSe we will infer to the stoichiometric disturbance of the implanted layer. After implantation the changes can be observed quantitatively by AES, too.
Channeling effects in polycrystalline copper—a serious impediment to quantitative Auger analysis?
Authors: Doern F. E. , Kover L. , McIntyre N. S. 
Published: May 2005

AbstractVariations in absolute Auger intensity of as much as 40% are reported for the analysis of polycrystalline copper surfaces in a high resolution scanning Auger microprobe. The angular dependent Auger yield is correlated with channeling effects of the incident electron beam. A correction procedure based upon ratioing the Auger peak intensity to the elastically backscattered electron peak, combined with an angular averaging technique can reduce the crystallographically induced Auger yield variations by a factor of four.
On the role of Gibbsian segregation in causing preferential sputtering
Authors: Kelly Roger 
Published: May 2005

AbstractIt is well known that preferential sputtering with binary alloys correlates significantly with chemical binding, but only the sense and not the magnitude of the effect can be understood in these terms. It is argued here that the correlation is, in fact, an indirect one due to bombardment‐induced Gibbsian (or similar) segregation. The preferentially removed component is characterized by a composition profile consisting of a one atom‐layer‐thick spike at the surface; this is the depth from which most sputtered atoms originated so the spike must have near‐bulk composition. There is then a severely depleted subsurface region in accordance with Gibbsian segregation equilibrium (or an equivalent effect) and a final return to bulk composition. The reason for the marked correlation with chemical binding is that segregation is governed significantly more often by binding than by the alternatives of size, surface chemistry, an interstitial flux, or long‐range ordering.
A multilayer model for GaAs oxides formed at room temperature in air as deduced from an XPS analysis
Authors: Demanet C. M. , Marais M. A. 
Published: May 2005

AbstractAn XPS study of the oxides formed on GaAs at ambient temperature and in ambient atmosphere is reported. Special attention has been paid to the interpretation of the Ga 3d and As 3d energy levels. By varying the angle between energy analysed electrons and the surface of the sample the depth distribution of the various oxides has been deduced. A multilayer model deduced from XPS analysis and the known reactivity of GaAs and the various oxides is proposed.
XPS study of iodine released in core melting experiments
Authors: Moers H. , Dillard J. G. , Klewe‐Nebenius H. , Kirch G. , Pfennig G. , Ache H. J. 
Published: May 2005

AbstractCore melting experiments are performed in order to investigate on a laboratory scale the behaviour of the reactor core constituents released during severe light water reactor accidents in the form of aerosols and the dependence on the temperature of the melting charge. The materials used reflect the composition of a pressurized water reactor core including structural materials, fuel, and fission products. One of the most important questions regards the release and chemical behaviour of fission product iodine.X‐ray photoelectron spectroscopy (XPS) of aerosol samples released at temperatures ranging from 1200 °C to 1900 °C revealed caesium, silver, indium, cadmium, iodine, and tellurium as constituents of the aerosol surface. The main compounds identified were: caesium hydroxide, silver metal, indium oxide, cadmium hydroxide, tellurium dioxide.The investigation of the chemical nature of iodine was difficult because of the low iodine concentration in the samples and because of the small chemical shifts in the photoelectron energies of the possible iodine compounds. The determination of its chemical states was possible with a combination of XPS and argon ion bombardment and resulted in identification of CsI and HgI. The procedure chosen required in addition a critical reflection on the influence of ion bombardment on the surface chemistry.
Oxygen coverage effects in SIMS quantitative analysis using a primary rastered probe
Authors: Lang J. M. , Degrève F. 
Published: May 2005

AbstractThe surface oxygen coverage θ has a great influence on positive secondary ion yield. θ must be equal to 1 for optimum quantitative analysis. On SIMS machines (like the CAMECA IMS‐3F) using a rastered high current density probe, instead of a static defocused (hence low current density) beam, there is a danger that this condition is not achieved where bombarding the sample with Ar+ ions while blowing O2 on to the sample. A simple model of the evolution of θ under the rastered probe is proposed; it provides a good frame to interpret surprising experimental results such as: (a) the existence of transients which can last for several seconds (primary Ar+); (b) the existence of cristallographic differential sputtering even though the oxygen back pressure is high; (c) the secondary signal can decrease when the primary beam intensity is increased. An easy and quick way of detecting conditions that would lead to erroneous interpretation is proposed.
Detection of water soluble flux residues on printed wiring boards by ESCA
Authors: Roberts R. F. 
Published: May 2005

AbstractThe use of water soluble flux (WSF) in soldering processes of electronics manufacture is desirable from environmental, economic, and technical standpoints. However, ineffective removal of WSF residues in post‐solder cleaning procedures may give rise to electrical malfunction or failure due to the chemical activity of WSF residues on various electronic components. In the present work, electron spectroscopy for chemical analysis (ESCA) has been used to detect WSF residues in the surface region of printed wiring boards (PWBs). This has been accomplished by examining PWB samples exposed to WSF, a soldering process, and a post‐solder cleaning procedure. The successful ESCA detection of WSF residues provides a direct means of evaluating the effectiveness of post‐solder cleaning procedures used to remove undesirable WSF residues.
Soft x‐ray appearance‐potential study of Ti–Ni system
Authors: Hatwar T. K. , Chopra D. 
Published: May 2005

AbstractSoft x‐ray appearance‐potential spectroscopy (SXAPS) probes the binding energies of the core levels and local unoccupied conduction‐band states of solid surfaces. This technique has been exploited to study the electronic structure of Ti–Ni alloys of atomic composition TixNi1–x where x = 0, 0.3, 0.5, 0.7, 1.0. The measured full width at half maximum (FWHM) of the Ti L3 peak systematically decreases with increasing Ni content while the Ni L3 peak shows a corresponding decrease. The binding energies of both constituents shift towards higher energy as a result of Fermi level shift and charge transfer from Ti to Ni. These measurements are in agreement with the common‐band model for these alloys.
Calibration of argon ion sputter rates using nuclear microanalysis and Auger spectroscopy
Authors: Tapping R. L. , Davidson R. D. , Jackman T. E. 
Published: May 2005

AbstractAuger electron spectroscopy (AES), in conjunction with argon ion sputtering, is frequently used to obtain composition versus depth profiles. Thin film thicknesses may be estimated from such profiles if the argon ion sputtering rate of a particular material is known. For this work, a series of oxide standards was prepared and calibrated with nuclear microanalysis techniques. These standards were then used to calibrate the composition versus depth profiles obtained using AES.
Effect of temperature during ion sputtering on the surface segregation rate of antimony in an iron–antimony alloy at higher temperatures
Authors: Oku M. , Hirokawa K. , Kimura H. , Suzuki S. 
Published: May 2005

AbstractThe surface segregation of antimony in an iron–0.23 at% antimony alloy was studied by XPS. The segregation rate in the temperature range between 800 and 900 K depends on the temperature during sputtering with argon ion of kinetic energy of 1 keV. The sputtering at room temperature or 473 K gives higher values of the segregation rate than those at 673 K. Both cases give the activation energy of 170 kJmol−1 for the surface segregation rate. The segregation of antimony is not observed after the sample is heated at 1000 K.
Use of oxygen Auger line relative intensities for characterization of surface oxides on oxidized metals and alloys
Authors: Laudet A. , Jardinier‐Offergeld M. , Bouillon F. 
Published: May 2005

AbstractExemplifying results from AES study of high temperature oxidation of dilute copper‐aluminium alloys, under low pressures of oxygen, are presented to demonstrate the feasibility of using changes in relative intensities of oxygen Auger lines as a diagnostic test for oxidation selectivity, at the very early stages of the reaction.
Computer graphics display of 3‐D analysis data
Authors: Watson S. G. , Millham C. B. , Lewis K. , Stulik D. 
Published: May 2005

AbstractThe development of a computer program to display results of 3‐D analysis is described and discussed. The program can data in the desired format, display a representation of a 3‐D grid in the recent version limited to 10 × 10 × 10 divisions, and fill the grid with colors and shades representing different chemical elements and their concentration. To allow a detailed inspection of the analyzed volume from different viewing angles, the whole 3‐D scene can be rotated to any desired position. To allow inspection of the interior of the analyzed volume, the display can be cross‐sectioned or scanned through in various directions. Capabilities and limitations of the program as well as unresolved problems and suggestions for its future development are presented. The program is tested using a model data file representing a simplified 3‐D microelectronic circuit and a complex shape inclusion in the matrix material.
Surface investigation, by XPS, ISS and IR spectroscopy of adsorbed NO, of the structural changes occurring during the reduction of Co‐Mo/γAl2O3 catalysts
Authors: Prada Silvy R. , Fierro J. L. G. , Delmon B. , Beuken J. M. , Bertrand P. 
Published: May 2005

AbstractThe structural changes produced during the reduction by H2 at different temperatures (300–800°C range) of a commercial Co‐Mo/γAl2O3 hydrodesulphurization catalyst have been investigated by x‐ray photoelectron spectroscopy (XPS), ion scattering spectroscopy (ISS) and infrared (IR) of absorbed NO, as a probe‐molecule. In all samples, different cobalt phases are observed. A fraction of cobalt interacts with the alumina support (CoAl2O4‐like, species which was reducible only at the highest temperatures) and another fraction forms a phase interacting with the molybdenum atoms (species easily reducible at moderate temperatures). XPS and ISS results indicated that, at reduction temperatures above 600°C, several effects are produced: (a) an increase of metallic cobalt, (b) a decrease of CoAl2O4 concentration and simultaneous crystallization of MoO2 species, and (c) a decrease of the molybdenum dispersion. From the IR spectra of NO probe chemisorbed on reduced catalyst at 800°C, it was concluded that the slight increase of the Co0 exposure could be due to reduction of CoAl2O4‐like species.
Structural and compositional studies of sputtered nickel ferrite films
Authors: Fitzgerald A. G. , Muir G. 
Published: May 2005

AbstractThe crystal structure, composition and surface composition of sputtered nickel ferrite films have been studied. The films have been prepared by sputtering in argon and reactively sputtering in oxygen from a nickel ferrite cathode and from an invar alloy cathode. Nickel ferrite has been identified as the main constituent of these films. XPS and AES have been used to study the surface composition of these sputtered films and NiFe2O4 and oxides and hydroxides of nickel and iron have been identified on the surface. Only films sputtered in argon from a nickel ferrite cathode were found to have the exact nickel ferrite composition. The deposition of these films onto single crystal MgO, a suitable substrate for epitaxial growth, has also been studied. AES results after annealing at 1000 °C indicate that for thin films, nickel and iron diffuse into the MgO substrate.
Quantitative surface analysis by glow discharge optical spectrometry
Authors: Pons‐Corbeau J. , Cazet J. P. , Moreau J. P. , Berneron R. , Charbonnier J. C. 
Published: May 2005

AbstractIn an analysis by glow discharge optical spectrometry the relation between the intensity of an optical emission line of an element and its concentration on the surface is exploited for quantitative determination of variations of composition in galvanized coatings and for an estimation of the enrichments on the surface of annealed extra mild steel sheets.
The application of laser ionization mass spectrometry to the study of thin films and near‐surface layers
Authors: Clarke N S , Ruckman J C , Davey A R 
Published: May 2005

AbstractThe laser ionization mass analyser, LIMA, was originally developed as a bulk microprobe instrument giving elemental information similar to that obtained from the conventional electron probe microanalyser, but with the advantage of full periodic table coverage. The LIMA is therefore capable of detecting all elements including hydrogen, helium, lithium, and beryllium, which are inaccessible to EPMA. Other advantages of LIMA over EPMA are isotope discrimination and the ability to obtain chemical information from materials as a result of the emission of complex ionic fragments from surfaces under laser irradiation. As experience grew with the use of the prototype LIMA at Aldermaston, it became clear that the technique was a particularly versatile tool which could not only perform well as a bulk microprobe, but with suitable experimental procedures could also be used as a sensitive depth profiling instrument with moderate depth resolution (≥0.01 μm). It became apparent that in its performance parameters, and in many of its applications in bulk and surface analysis, LIMA was directly comparable with dynamic SIMS. This paper is, therefore, concerned with the applications of LIMA when operated in a surface sensitive mode. In general, this involves using low power densities, and a defocused laser—the defocusing means that some sacrifice in lateral resolution must be made. Nonetheless, it is shown in this paper that the LIMA has a genuine contribution to make in depth profiling and thin film analysis.
Surface chemical analysis—report on the vamas project
Authors: Powell C. J. , Seah M. P. 
Published: May 2005

AbstractThe VAMAS project on surface chemical analysis is a multi‐national cooperation for the provision of standards data and materials for surface chemical analysis measurement and for the provision of the basic understanding necessary for these activities. This project is one of a rapidly growing suite of projects initiated as a result of decisions following the 1982 Versailles Summit Meeting of the Heads of State or Government of Canada, France, Germany, Italy, Japan, UK, USA and the representatives of the Commission of the European Communities. During the past year national representatives to this VAMAS project have been appointed and national committees established. This article summarizes the philosophy, scope, and organization of the project and describes specific activities that have been initiated. Information is given on how individuals, both within and outside the group of member states, may participate.
Prediction of auger backscattering factors from measurements of spectral backgrounds
Authors: Prutton M. , El Gomati M. M. 
Published: May 2005

AbstractThe shape of N(E) has been obtained from a carefully characterized electron spectrometer for 24 different elements and compounds. The secondary electron cascade has been found to obey a form N(E) = AE−m. A and m have been measured and used together with a model of the energy distribution of rediffused primary electrons to calculate an Auger backscattering factor for each material when the primary energy is 20 keV. These calculations have been compared with backscattering coefficients measured at the carbon 1s binding energy in the same instrument on the same samples. The results show the backscattering factor to be linear in atomic number. The measurement of A and m from a spectrum can be used to estimate the backscattering factor within an estimated error of about ±0.05.
Surface segregation in Fe‐18Cr‐3Mo single crystal
Authors: Schiffman B. , Polak M. 
Published: May 2005

AbstractThe (100) surface region of the Fe‐18Cr‐3Mo ternary alloy was investigated during and after argon sputtering at ambient and elevated temperatures by means of Auger electron spectroscopy. Low and high‐energy lines, corresponding to different sampling depths, were monitored, and the quantitative analysis was based on relative intensities from an in situ scribed crystal, representing the bulk composition. The Cr:Fe steady‐state ratio measured during sputtering reflected significant subsurface Fe depletion which reached a maximum at ∼800 K and then decreased. This trend could be inverted (i.e. inducing Cr depletion) by Ar sputtering under some residual CO. Similarly, compositional changes observed after sputtering were critically dependent on the cleanliness of the surface. The results are discussed in terms of possible (Gibbsian) surface segregation of Fe vs. chemically‐induced segregation of Cr and Mo.
Analysis by scanning electron microscopy and structure determination by high resolution electron microscopy of ni/ni3b eutectic
Authors: Desseaux‐Thibault J. , Hamar‐Thibault S. 
Published: May 2005

AbstractThe eutectic Ni/Ni3B has been found in a number of special hardfacing alloys such as Ni‐Cr‐B‐Si. However, this eutectic has not been studied. This eutectic is a good model. Ni3B has the same crystallographic structure as Fe3C. The combination of HREM with EDX and EELS is a means to obtain together data on composition and morphology of defects and grain boundaries. Here an attempt is made to determine the structure by HREM and to analyse by EELS both Ni and Ni3B. Images of low indexed planes of Ni3B are obtained and interface observed.
Surface analysis and the complexity of real catalysts
Authors: Delmon Bernard 
Published: May 2005

AbstractThis paper is written for specialists of surface techniques not perfectly familiar with catalysis, as well as for scientists working in the area of heterogeneous catalysis. It is aimed at suggesting the problems of characterization that surface analysis is faced with, because of the complexity of real catalysts. We first present the various typical ‘architectures’ to which catalysts may correspond. We shall then illustrate typical problems, and their solutions, by selecting examples in the field of hydrodesulfurization (HDS) catalysts. We shall show how 10 out of the 12 theories proposed for explaining catalytic activity were eliminated thanks to surface techniques. HDS catalysts are remarkable in several respects, especially because they undergo many ‘metamorphoses’ (activation, modifications during catalytic work, ageing, regeneration) from the time of their preparation to that of their death by irreversible deactivation. They therefore provide a large body of illustrative examples concerning the characterization of several ‘architectures’. In spite of the achievements of surface techniques in clarifying many features of HDS catalysts during their life, investigators are still faced with unsolved problems; many such problems are related to the very fine scale (of the order of 1 nm or less) of the details of importance for catalysis. This might suggest directions for new improvements or the development of new surface techniques. As a conclusion, we shall recall that, because complete characterization needs the joint use of several techniques, a methodology of study had to be developed, now exists, and still continues to improve. The main lines of this general methodology are not restricted to catalysts, but can be used for the study of all complex highly dispersed solids.
Characterization of supported bimetallic FeIr/SiO2 catalysts by mössbauer spectroscopy, temperature‐programmed reduction and X‐ray photoelectron spectroscopy
Authors: Niemantsverdriet J. W. , van der Kraan A. M. 
Published: May 2005

AbstractSupported bimetallic FeIr/SiO2 catalyst have been chacterized by in situ Mössbauer spectroscopy, temperature‐programmed reduction (TPR) and XPS. The reduction of iron in freshly prepared FeIr/SiO2 catalysts is greatly facilitated by the noble metal iridium. Reduced catalysts consist of Ir‐rich fcc FeIr alloys, possibly some isolated Ir metal, and significant amounts of iron (III) oxide. The Mössbauer parameters of the latter change when the catalyst is exposed to CO gas at room temperature, indicating that the iron (III) oxide is present in a highly dispersed phase. Evacuation of reduced samples at 475 or at 775 K leads to significant oxidation of the iron in the catalyst, most likely by OH groups on the SiO2 support.
Perspectives in surface and interface analysis for electronic devices and circuits
Authors: Heckingbottom R. 
Published: May 2005

AbstractOver the past two decades a variety of techniques have been developed for the analysis of surfaces and interfaces. Despite the multiplicity of interfaces in electronic devices however, and the need for precise control, surprisingly few of these techniques have had a major impact in the area. Scientific successes such as low energy electron diffraction (LEED) find little application, and a straightforward comparison of the strenths and weaknesses of Auger electron spectroscopy (AES) and x‐ray photo‐electron spectroscophy (XPS) gives little indication of the massive preference for the former in analysing devices and circuits. A similar disparity in usage has also arisen between dynamic and static SIMS, only the former being significant. It is also clear that several of the more important techniques can be used to analyse thin films as well as surfaces and interfaces. Further, that the techniques are often more quantitative in their application to films. Again it is surprising how little pressure there has been to minimise the shortcomings with respect to interface analysis.With the benefit of hindsight, some of the features that have led to certain techniques becoming particularly useful in application will be considered. Some new trends in device and circuit research which may increase the emphasis on surface and interface analysis will be identified. In this new area the growing importance of techniques such as transmission electron microscopy, not automatically included as a leading surface and interface analysis technique, will be illustrated.
A characterization study of the native Oxide layer formed on chemically Etched InP (111)
Authors: Hoflund Gar B. , Corallo Cheryl F. 
Published: May 2005

AbstractISS, AES and angle‐resolved ESCA have been used to characterize the native oxide layer formed on the chemically polished and etched InP (111) surface. It is estimated that this oxide layer is about 30 Å thick and forms a sharp interface at the oxide/InP boundary. The oxide layer is nonhomogeneous. ISS shows that the outermost surface layer is In rich, and AES combined with the ISS results shows that the region just below the surface layer is P rich. The In is believed to be present in the oxide layer as InP and InPO3 in approximately equal concentrations. Only a small amount of In2O3 is detected. Carbon also comprises the oxide layer, and ESCA shows that it is present as graphite and/or hydrocarbons. The region below the oxide layer is P rich, but depth profiling using AES while sputtering suggests that the composition may approach that of InP with increasing depth.