bluuebunny/crossref_metadata_2025_split huggingface dataset:
Absolute background determination in XPS
Authors: Tougaard S. , Jørgensen B. 
Published: May 2005

AbstractA recent method, which contains no adjustable parameters, is used to deconvolute the background intensity of inelastically scattered electrons from the XPS spectrum of silver in the 200–900 eV kinetic energy range. The inelastic background signal is found to match the measured spectrum in the energy regions between peaks. In the deconvoluted spectrum the behaviour on the low energy side of each peak is similar, with a tail of primary electrons extending ∼50 eV below the peak. The range of validity of the deconvolution procedure is discussed.
Electron and ion beam degradation effects in AES analysis of silicon nitride thin films
Authors: Fransen F. , Berghe R. Vanden , Vlaeminck R. , Hinoul M. , Remmerie J. , Maes H. E. 
Published: May 2005

AbstractSilicon nitride films are currently investigated by AES combined with ion profiling techniques for their stoichiometry and oxygen content. During this analysis, ion beam and primary electron effects were observed. The effect of argon ion bombardment is the preferential sputtering of nitrogen, forming “covalent” silicon at the surface layer (AES peak at 91 eV). The electron beam irradiation results in a decrease of the covalent silicon peak, either by an electron beam annealing effect in the bulk of the silicon nitride film, or by an ionization enhanced surface diffusion process of the silicon (electromigration). By the electron beam annealing, nitrogen species are liberated in the bulk of the silicon nitride film and migrate towards the surface where they react with the covalent silicon. The ionization enhanced diffusion originates from local charging of the surface, induced by the electron beam.
Calculations of electron inelastic mean free paths from experimental optical data
Authors: Powell C. J. 
Published: May 2005

AbstractCalculations are reported of inelastic mean free paths (IMFPs) for 100–2000 eV electrons in C, Mg, Al, Al2O3, Cu, Ag, Au, and Bi from experimental optical data. These calculations require knowledge of the momentum‐transfer dependence of the differential scattering cross section; this information was taken from Penn's calculations. The calculated IMFPs agree reasonably with direct calculations and with measured electron attenuation lengths (ALs). Since accurate measurements of ALs are difficult, it is suggested that calculations of the present type are useful if the needed optical data are available. The present approach is also useful for materials (such as the transition and noble metals) for which it is not possible to make a meaningful distinction between valence‐electron and core‐electron excitations as required in current IMFP calculations. The dependence of the calculated IMFPs on electron energy varied with material and was associated with different spectral distributions of the electron energy‐loss function. The trend in the dependence of IMFP on energy was similar to that found in analysis of AL data.
XPS study of ion‐induced changes on the surface of an organosilicon model polymer
Authors: Tóth A. , Bertóti I. , Székely T. , Mohai M. 
Published: May 2005

AbstractChanges in composition and bonding induced by bombardment with argon or nitrogen ions in a commercial poly‐methyl‐phenyl‐cyanopropyl‐siloxane fluid were examined by XPS. The actual surface composition depended on the ion energy, the etch time and the nature of the gas applied. It was found that phenyl groups were damaged seriously, reaction of the cyano groups took place with the formation of CN type bonds and the polymer degraded with elimination of fragments containing mostly C at the first stage and mainly O and Si at advanced stages. In addition nitrogen was found to build into the polymer surface when bombarding by nitrogen ions. Irreversible changes in the spectra of the fluid polymer were regarded as a sign of crosslinking.
An experimental investigation of backscatter factors in Auger spectroscopy
Authors: Underhill P. R. 
Published: May 2005

AbstractA systematic experimental investigation of relative backscatter factors as a function of primary beam energy and substrate atomic number using the carbon KLL and copper LMM Auger peaks is described. The results are compared to the Monte Carlo calculations of Ichimura et al. (1981). Good agreement between experiment and theory is found in the case of large overpotentials but the theorietical calculations are found to overestimate the backscatter contribution with increasing Z as the overpotential decreases.
Study of interfaces in oxidized Fe/Si system by XPS and XAES: Use of the Auger parameter
Authors: Rivière J. C. , Crossley J. A. A. 
Published: May 2005

AbstractAuger Parameters for a variety of silicon compounds have been measured by a combination of XPS using both AIKα ZrLα characteristic x‐radiation, and of XAES using Bremsstrahlung radiation. The Parameters so derived have then been used to study the chemical states of silicon at and near interfaces in the oxide film formed by air‐and CO2‐oxidation of Fe/Si alloys. Supportive evidence for the interpretations is provided by the widths and shapes of the silicon KL2,3 L2,3 Auger peaks.
The characterization of heterogeneous catalysts by XPS based on geometrical probability 1: Monometallic catalysts
Authors: Kuipers H. P. C. E. , Van Leuven H. C. E. , Visser W. M. 
Published: May 2005

AbstractGeometrical probability can be used as a basis for the quantification of XPS‐signals stemming from random samples such as, for instance, supported heterogeneous catalysts. From a study of three ideal cases, namely extended layers of constant thickness, equally sized spheres and hemispheres on a randomly oriented support, it has been established that the effects of angular and layer thickness averaging are interconnected in such a way that a general model can be derived. It has been found that signal ratios as measured by XPS for convex particles are determined by the surface/volume ratios of the supported phases, nearly independent of particle shape.
Mechanism of silicon surface roughening by reactive ion etching
Authors: Oehrlein Gottlieb S. , Schad Robert G. , Jaso Mark A. 
Published: May 2005

AbstractRough silicon surfaces resulting from CF4 reactive ion etching have been studied by scanning electron microscopy/scanning Auger microscopy and x‐ray photoemission spectroscopy. The experimental data demonstrate a roughening mechanism based on laterally non‐uniform etch rates due to the existence of involatile surface residues.
Probing polymer surface and interface dynamics
Authors: Andrade J. D. , Chen W.‐Y. 
Published: May 2005

AbstractPolymeric materials generally exhibit various molecular motions and relaxations. Such relaxation processes, which include the glass transition temperature, have significant effects on physical and mechanical behavior. Polymer molecules and segments at surfaces and interfaces also exhibit motions and relaxations. In air or vacuum, such motions ‘permit’ the surface to restructure to minimize the surface free energy. In aqueous solution, the polymer surface restructures and reorients to optimally interact with the aqueous solvent, thereby minimizing the interfacial free energy. XPS and related high vacuum techniques probe the vacuum‐equilibrated surface. The best way to probe the polymer‐liquid interface is via dynamic contact angle or wetting methods. A number of issues and concerns are discussed: (1) the size or hierarchy of structures: (2) the time course of surface dynamic processes; (3) theory, modeling, and simulation of surface dynamics; and (4) experimental methods.
Data compilations: their use to improve measurement certainty in surface analysis by aes and xps
Authors: Seah M. P. 
Published: May 2005

AbstractData compliations are an integral and vital part of the development of the measurement scheme for surface analysis. They have three main functions that will be considered in this survey: (i) the provision of numerical values for use in calculations of quantitative surface analysis, (ii) the provision of unbiased data for the development of theory, and (iii) the establishment of a benchmark to judge the value of current research. A brief review will be made of practical data relating to AES and XPS instruments; electron guns, x‐ray sources, spectrometers and detectors. Next, data compilations of experimental measurements of relative sensitivity factors, attenuation lengths and backscattering factors will be contrasted. Finally, theoretically derived data banks of cross sections, inelastic mean free paths, asymmetry parameters, etc will be considered and conclusions drawn of the need for further work.
Characterization of the imaging properties of a double‐pass cylindrical‐mirror analyzer
Authors: Erickson N. E. , Powell C. J. 
Published: May 2005

AbstractThe imaging properties of a double‐pass cylindrical‐mirror analyzer have been investigated using extensions of the technique recently described by Seah and Mathieu. Elastic‐peak intensity data obtained as an electron beam was rastered across a test specimen, was recorded in digital form and later used to generate ‘three‐dimensional’ images. Images have been obtained for a range of operating conditions and for displacements of the specimen from its optimum position. Measured image widths were in semi‐quantitative agreement with those expected from a simple analysis although deviations attributed to instrument imperfections were found. Elastic‐peak images provide a convenient and quantitative means of assessing instrument performance and defining the specimen area being analyzed for the selected conditions.
Measurement of the sputtering yield with a 3d stylus surface mapping system: application to copper and α‐brass
Authors: Quantin J. C. , Darque‐Ceretti E. , Combarieu R. , Delamare F. 
Published: May 2005

AbstractThis paper present a method for determing the sputtering yield of a material bombarded by an ion beam, using a 3D stylus surface mapping system. Data obtained of copper are discussed. The influences on the sputtering yield of progressive addition of zinc is observed. The results are in good agreement with previous theoretical results.
Grazing incidence x‐ray diffraction of an aisi 1006 nitrogen implanted steel
Authors: Moncoffre N. , Brunel M. , Deydier P. , Tousset J. 
Published: May 2005

AbstractNitrogen implantations were performed on a very low alloyed steel XC06, AISI 1006 at various doses (1017, 2 × 1017, 4 × 1017 ions cm−2) and various temperatures (20, 100, 150, 200°C). A study of the nitride phase evolution as a function of the two parameters (dose and temperature) is performed. The nitrogen distribution profiles are obtained using the 15N(p, αγ)12C nuclear reaction whereas the iron nitride phases are followed by means of glancing angle RX diffraction. (N)‐martensite, ε‐nitride and ε‐carbonitride phases of different nitrogen and carbon composition are identified. These results are correlated with Mössbauer results that put in evidence a carbonitride formation depending on implantation temperature and with recent Rutherford backscattering results that quantify the carbon contamination depending on implantation conditions. Moreover a preferential orientation of these phases depending on temperature is noticed.
XPS and AEM studies of carbon‐supported HDS catalysts
Authors: Brinen J. S. , Allard L. F. , Daly F. P. 
Published: May 2005

AbstractA series of carbon‐supported HDS catalysts has been characterized by XPS and high resolution analytical electron microscopy. the size, distribution and composition of clusters or particles of Co and Mo oxides on the support materials is shown to be related to variations in processing treatments. These results are discussed in terms of catalyst activity measurements and surface analytical information (XPS data).
Electronic state and catalytic activity of SiO2 doped γ–Al2O3
Authors: Bertóti I. , Mink G. , Székely T. , Varsányi G. , Réti F. 
Published: May 2005

AbstractSilica‐alumina catalysts have been applied for a long time in cracking and reforming reactions. Lewis type surface sites are generally accepted to serve as active centers. In this respect, surface properties of these materials are of main concern. In the present work SiO2 doped γ‐Al2O3 with less than a monolayer coverage were prepared by the reaction of SiCl4 (g) with γ‐Al2O3 at 820‐1120 K. Catalytic activity of the samples was tested by a model reaction of n‐hexane cracking. Surface composition and electronic state were evaluated by XPS investigations performed on a KRATOS XSAM 800 instrument. Catalytic activity (conversion) varies remarkably with increasing Si content showing a sharp maximum at low Si coverage. The observed shift of Al 2p lines with increasing Si content is interpreted as an enhancement of the acceptor or acidic character of the surface Al atoms. The Auger parameter for Si(α'Si), (composed by addition of Si 2p BE and Si (KLL) KE values) passes also through a maximum at the same Si‐content, as does the conversion curve. A close correlation of the Auger parameter and the catalytic activity is established for samples with (Si/Al)≲7%. This leads to a conclusion, that the rise in extra‐atomic relaxation energy may serve as an additional indication of enhanced catalytic activity.
Study of near‐surface disorder and surface residues after reactive Ion etching of Silicon
Authors: Oehrlein G. S. , Coyle G. J. , Clabes J. G. , Lee Y. H. 
Published: May 2005

AbstractHelium ion channelling, nuclear reaction profiling and x‐ray photoemission measurements of CF4/X%H2 (0≤X≤40) and CCIF3/50%H2 dry etched Si surfaces are reported. It is shown that plasma exposure of a clean Si surface leads to the deposition of a thin (∼30∼50) Å thick C,F‐containing film (or C,F, C1‐containing in the case of CC1F3/H2 etching). A subsurface Si carbide layer is formed during reactive ion etching. The near‐surface region (∼30∼50 Å) of the Si substrate is heavily disordered as found by ion channeling. A modified, less damaged layer containing a high concentration of hydrogen is formed in the case of the H2 containing gases (as shown by nuclear reaction profillin) and extends more than 250 Å from the surface. It is found that heating the plasma exposed substrates to 400°C in dry O2 for 30 min is efficient in recovering good quality Si surfaces.
Applications of SIMS, SAES and XPS to problems in the semiconductor industry
Authors: Alnot P. , Huber A. M. , Olivier J. 
Published: May 2005

AbstractElectronic devices based on III‐V compounds can be significantly affected in their behaviour by surface and interface properties. This paper will show the usefulness of surface and interface analytical tools such as SIMS, SAES and XPS in overcoming such problems. Case studies in relation with some of the main problems of III‐V compounds technologies will be described.
The role of electron spectroscopy in corrosion science
Authors: Castle J. E. 
Published: May 2005

AbstractThe two principal electronspectroscopies – photoelectron and Auger electron – now represent the mature methods of surface analysis and both have been used to further the study of corrosion almost since their inception. This review will examine those areas in which significant developments have been made by their use and will highlight their continuing role in post‐corrosion failure analysis.Specific topics which will be covered include: (1) aqueous corrosion: the formation and composition of passive layers, their interaction with surrounding solutions, and their failure by pitting and stress corrosion; (2) coated surfaces: pretreatment for coating, locus of failure and disbonding under chemical or electrochemical attack; and (3) high temperature oxidation: segregation to the surface, the formation of stable layers and interlayer reaction, and the composition of barrier layers and of spalling interfaces.
XPS study of sizing removal from carbon fibers
Authors: Santiago F. , Mansour A. N. , Lee R. N. 
Published: May 2005

AbstractX‐ray photoelectron spectroscopy (XPS) was used to investigate the effectiveness of the techniques commonly used to remove polyvinyl alcohol (PVA) sizing from graphitized carbon fibers. Unsized samples of P55 and P100 mesophase‐pitch fibers were used as standards for comparison and the oxygen‐to‐carbon ratio on the fiber surfaces was the primary criterion for judging the degree of sizing removal. No significant change in fiber sizing was found to result from either ‘burn‐off’ in air or soaking in boiling water. Characterization of as‐received sized fiber revealed that the PVA surface undergoes major changes in composition as a result of normal ageing processes. The unsized fibers were found to have extremely low levels of adsorbed oxygen and no detectable hydrocarbons after extended exposure to air. Direct comparison with cleavage surfaces of Ticonderoga graphite showed that unsized pitch fiber surfaces are chemically indistinguishable from the basal plane of graphite, with a very low defect density which decreases with increasing fiber modulus. The implications for carbon‐fiber‐reinforced composite technology are discussed.
Deconvolution as a correction for photoelectron inelastic energy losses in the core level XPS spectra of iron oxides
Authors: Hawn David D. , DeKoven Benjamin M. 
Published: May 2005

AbstractIn this paper core level XPS spectra of polycrystalline Fe metal and several oxides are corrected by deconvolution using the ratio method for energy loss effects and spectral broadening due to both an achromatic x‐ray source and finite analyzer resolution. These ideas are applied to the XPS spectra of Fe, FeO, Fe2O3, and Fe3O4 in order to obtain the intrinsic lineshape. The backscattered electron energy loss spectra are effective in distinguishing Fe and its oxides. For Fe metal and its oxides, the electron energy loss deconvolved spectra have a flat baseline and enhanced resolution. This background removal method is found to be more reliable than either linear or sigmodial background approximations. This allows for a determination of the relative sensitivity factor for the Fe 2p and O 1s core levels.
Applications of factor analysis to electron and ion beam surface techniques
Authors: Solomon J. S. 
Published: May 2005

AbstractFactor analysis, a mathematical technique for extracting chemical information from matrices of data, is used to enhance Auger electron spectroscopy (AES), core level electron energy loss spectroscopy (EELS), ion scattering spectroscopy (ISS), and secondary ion mass spectroscopy (SIMS) in studies of interfaces, thin films, and surfaces. Several examples of factor analysis enhancement of chemical bonding variations in thin films and at interfaces studied with AES and SIMS are presented. Factor analysis is also shown to be of great benefit in quantifying electron and ion beam doses required to induce surface damage. Finally, examples are presented of the use of factor analysis to reconstruct elemental profiles when peaks of interest overlap each other during the course of depth profile analysis.
Chemical state depth profiles from SIMS ion energy distributions using factor analysis
Authors: Solomon J. S. 
Published: May 2005

AbstractThe energy distribution curves of secondary ions are affected by the chemical state of surface atoms. Variations in these distributions due to changing chemistry were used to construct chemical state profiles of surface layers. Factor analysis of Ta+ energy distribution curves, recorded while sputter profiling anodized tantalum, is shown to provide quantitative profiles of the two chemical states of tantalum present in the oxide/metal structure.
XPS study of reduction effects in Nb‐doped PZT ceramics
Authors: Rajopadhye N. R. , Bhoraskar S. V. , Badrinarayan S. 
Published: May 2005

AbstractElectrical conductivity in lead zirconate titanate ceramic containing niobium oxide as impurity showed a marked increase when it was reduced in hydrogen atmosphere. X‐ray photoelectron spectra were used to investigate the chemical behaviour of the reduction products. Depth profiling for reduced Nb‐doped PZT indicated the presence of metallic Pb, whereas Zr, Ti and Nb did not exhibit any change in the valency. The amount of PbO showed a marked increase on the surface compared to that of inner layers in the samples. On the basis of the observed results the increase in the electrical conductivity is correlated to the oxygen vacancies produced because of the reduction in hydrogen.
Surface modification of a contact lens co‐polymer by plasma‐discharge treatments
Authors: Fakes D. W. , Newton J. M. , Watts J. F. , Edgell M. J. 
Published: May 2005

AbstractXPS and contact angle measurements have been used to investigate the surface modification of an alkyl‐acrylate/polysiloxane co‐polymer by plasma‐discharge treatments. The improved wettability brought about by the plasma treatments is shown to result from the oxygenation of the surface layers and the conversion of the polysiloxane component to a silica‐like phase. By analysis with MgKα, AlKα, and AgLα induced XPS this oxygenation is shown to decrease with depth. The total thickness of this altered zone has been estimated by comparing these results with data from argon ion bombardment studies.
From SEXAFS to SEELFS
Authors: Woodruff D. P. 
Published: May 2005

AbstractSurface extended x‐ray absorption fine structure (SEXAFS) is now becoming an established method of surface structural analysis. The basic method is described and examples of its application are given with particular emphasis on the potential of the method to investigate structural problems in applied surface science. Developments in the application of the same physical effects in electron ionization are reviewed, particularly in surface electron energy loss fine structure (SEELFS), and some of the relative merits of the methods, at their present states of development, are discussed.
Simultaneous AES and SIMS depth profiling of standard Ta2O5 films
Authors: Mathieu H. J. , Landolt D. 
Published: May 2005

AbstractStandard Ta2O5 30 nm films have been applied for simultaneous Auger electron analysis (AES) and secondary ion mass spectroscopy (SIMS) to characterize and calibrate depth porifles. A combined SIMS/AES‐system (Atomika Kit 3000–30/Perkin Elmer PHI 545) was used applying 2–12 keV Ar+ primary beam energy with/without Wien filter at almost normal incidence (2° off normal to avoid neutral particles). The investigated parameters were ion‐beam energy, raster frequency, Wien filter and influence of simultaneous electron beam. Optimum depth resolution at almost normal incidence was found to be 1.7 nm for O–AES and O+ (16)‐SIMS peak.