bluuebunny/crossref_metadata_2025_split huggingface dataset:
The interaction of imidazole, benzimidazole and related azoles with a copper surface
Authors: Tompkins H. G. , Sharma S. P. 
Published: December 2004

AbstractAzoles such as benzotriazole and benzimidazole are used as corrosion inhibitors, particularly for copper. The purpose of this work is to further illuminate the bonding and film growth for benzimidazole‐like structures. The interaction of imidazole, benzimidazole, 2‐methylbenz‐imidazole and benzotriazole with copper surfaces is studied with a quartz crystal oscillator microbalance and with X‐ray photoelectron spectroscopy. The copper surface is etched by imidazole in water and in CH3OH and by benzimidazole in CH3OH. A very thin film, probably a monolayer or less, is left behind after etching. Thicker films, 500 to 1000 AÅ, are formed by benzimidazole in water and by 2‐methylbenzimidazole in both water and CH3OH. Mechanisms of bonding and film formation for the thin and the thick films are discussed.
Ion sputtering in the surface analysis of practical surfaces
Authors: Keenlyside M. , Stott F. H. , Wood G. C. 
Published: December 2004

AbstractThe routine analysis of many practical, engineering specimens utilizing sputter‐etch, in‐depth profiling, coupled with a surface‐analysis technique, is severely restricted by the roughness of the surface under study. Limitations imposed by the irregularities in such surfaces have been examined and a method of relating the subsequent degradation of the in‐depth profile to the specimen roughness is described. This method has been used to assess the value of in‐depth profiling for surfaces produced in practical situations. In addition, the importance of specimen‐incident sputtering‐beam geometry in optimizing the uniformity of etching over a rough specimen surface, using a number of different arrangements, is evaluated.
Barrier‐Type anodic films on aluminium in aqueous borate solutions: 1—Film density and stopping power of anodic alumina films for alpha particles
Authors: Skeldon P. , Shimizu K. , Thompson G. E. , Wood G. C. 
Published: December 2004

AbstractStopping powers of an anodic film, formed on aluminium in aqueous ammonium pentaborate solution, have been measured experimentally for α particles, over the energy range 0.7–2.3 MeV. Comparison between the measured stopping powers and theoretically calculated values shows that Bragg's Rule may be applied, with reasonable accuracy (∼5%), to predict the stopping powers of anodic alumina. The density of the barrier‐type film was determined by Rutherford backscattering spectroscopy to be 3.10±0.15 × 103 kg m−3.
Study of emission and sputtering yields in some alloys and oxide by glow discharge optical spectrometry: Quantification of analysis
Authors: Pons‐Corbeau J. 
Published: December 2004

AbstractIn an analysis by glow discharge optical spectrometry (GDOS) the relation between the intensity of spectral emission of an element and its concentration at the surface of the sample is fundamental for interpreting the results. The different factors which occur in this relation are systematically investigated for different materials such as metallic alloys, oxidized matrices or matrices submitted to ionic implantation. The measurements show that the emission yield of an element is independent of the matrix although particular phenomena can affect the apparent experimental values. The simplification which results in the interpretation of experiments in GDOS is evident and a few examples of applications are presented.
Edge effects and image contrast in scanning Auger microscopy: A theory/experiment comparison
Authors: El Gomati M. M. , Prutton M. , Lamb B. , Tuppen C. G. 
Published: December 2004

AbstractThe contribution of surface roughness to the artefacts present in images and line‐scans from Scanning Auger Microscopes have been explored by Monte Carlo modelling and by experiment. The samples chosen for these studies are metal lines with sharp rectangular cross‐sections deposited upon silicon substrates. The Monte Carlo simulation reveals shadowing effects due to the analyser/sample geometry and the obstruction due to the height of the overlayer line; forward scattering effects through the sidewall of the overlayer which lead to edge enhancements in the overlayer and substrate Auger signals; back‐scattering effects which show up as an apparent broadening of the overlayer lines and substrate signal peaks appearing in the otherwise forbidden shadowed region. All of these effects are visible in the experimental results obtained for Si substrates with Al and with Au lines upon them. The experimental edge enhancement artefact is compared with the results of the simulation and good agreement is obtained. The difficulties which arise in the separation of topographical and chemical contrast are discussed and some suggestions for removal or reduction of the magnitude of these effects are outlined.
Elastic electron backscattering for quantitative elemental analysis of laser diode structures
Authors: Szostak D. J. , Thomas J. H. 
Published: December 2004

AbstractA backscattered electron technique has been used to improve the spacial resolution and elemental sensitivity beyond that obtained from standard Auger microprobe electron spectroscopy. The elastically backscattered electron peak amplitude has been measured on a five‐layer laser structure of GaAs/AlGaAs with a CMA detector operating in the beam brightness modulation mode (BBM). Variations in elastic peak amplitude across these layers have been calibrated by standards to determine variations in aluminium concentration with 6% accuracy in areas as small as 0.25 μm diameter at atomic sensitivity of better than 1%. These results represent a significant improvement over the spatial resolution and elemental sensitivity available from standard Auger analysis in which backscattering contributions make the total analyzed area larger than the primary beam size.
The correlation of chemical structure and electrical conductivity in polypyrrole films by x‐ray photoelectron spectroscopy
Authors: Zeller M. V. , Hahn S. J. 
Published: December 2004

AbstractX‐ray photoelectron spectroscopy was used to track chemical structure changes in conducting polypyrrole films which were electrochemically grown at various current densities. The film structures were correlated to changes in the film electrical conductivities. High resolution spectra of the C 1s, N 1s and O 1s regions were recorded. Concentrations of the charge compensating counter‐ions used in the growth of the film were also monitored and correlated to electrical performance. Results indicated that the films grown at low current densities contained hydroxide anions and deprotonated nitrogen species, while films grown at high current densities contained no hydroxide ions or deprotonated nitrogens and exhibited higher charge removal from the pyrrole ring. At medium current densities, the amount of incorporated dopant anion was maximized.
Surface analysis of Ti6Al4V adhesive bonding systems
Authors: Clearfield H. M. , Cote G. O. , Olver K. A. , Shaffer D. K. , Ahearn J. S. 
Published: December 2004

AbstractTitanium surfaces that have been prepared for adhesive bonding are difficult to characterize because they exhibit micro‐rough and, in some cases, macro‐rough morphologies, Errors can arise in the interpretation of sputter depth profiles obtained from such surfaces dur to the analysis geometry, i.e. large sampling probes and shadowing of the ion etching beam. This can be avoided either by scanning Auger microscopy or by x‐ray photoelectron spectroscopy to obtain estimates of the surface layer composition and thickness. We illustrate the utility of both techniques by studying the mechanisms of failure in adhesive bonds formed at Ti6Al4V surfaces before and after exposure to air at 330°C for 165 hours.
Auger electron spectroscopy and x‐ray photoelectron spectroscopy of the biocorrosion of copper by gum arabic, bacterial culture supernatant and Pseudomonas atlantica expolymer
Authors: Jolley John G. , Geesey Gill G. , Hankins Michael R. , Wright Randy B. , Wichlacz Paul L. 
Published: December 2004

AbstractThin films (3.4 nm) of copper on germanium substrates were exposed to 10% gum arabic aqueous solution, 1% bacterial culture supernatant (BCS) (aqueous and simulated sea water solutions) and 0.5% Pseudomonas atlantica exopolymer (aqueous and simulated sea water solutions). Pre‐ and post‐exposure characterization were done by Auger electron spectroscopy and x‐ray photoelectron spectroscopy. Ancillary graphite furnace atomic absorption spectroscopy was used to monitor the removal process of the copper thin film from the germanium substrate. Results indicate that the copper was oxidized by the gum arabic and BCS, and some was removed from the Cu/Ge interface by all three polymers and incorporated into the polymer matrix. Thus, biocorrosion of copper was exhibited by the gum arabic, BCS and Pseudomonas atlantica exopolymer.
Secondary electron emission characteristics of oxidized beryllium cathodes
Authors: Ritz Victor H. , Thomas Richard E. , Gibson John W. , Klebanoff Joseph 
Published: December 2004

AbstractOxidized beryllium surfaces are used in a number of microwave crossed‐field amplifier (CFA) tubes as secondary electron emission cold cathodes. During operation the cathode surface is subjected to electron and ion bombardment in a complex process which produces both erosion and replenishment of the oxide surface, in addition to a significant build‐up of amorphous carbon. The result is a general degradation of tube performance. Special techniques were developed to opoen an evacuated tub and transfer the cathode to a UHV surface analysis system with minimal contamination from the atmosphere. Three CFA tubes with various histories of operation were examined and measurements from made of the secondary electron emission (delta), first crossover, voltage at delta maximum, and the surface chemical composition by AES at several points on each cathode. Significant differences were found which reflected their number of hour of operation, as well as variations in manufacturing procedures. A generalized linear cofrrelation between secondary electron emission and the surface carbon atomic fraction was obtained when the data for all the tubes was combined and analyzed. The deleterious effects of carbon in operated CFA tubes were confirmed and suggest that reduction of potential sources of carbon contamination in the tube during manufacture, processing, and operation should improve overall performance.
Characterization of surface pretreatments of carbon fiber–polyimide matrix composites
Authors: Moyer Denise J. D. , Wightman J. P. 
Published: December 2004

AbstractVarious surface pretreatments of carbon fiber–polyimide matrix composites have been studied by XPS, ISS, PASFTIR (photoacoustic Fourier transform infrared spectroscopy) and high‐resolution SEM. Reduction of fluorocarbons from release cloth contamination and increase in carbon–oxygen‐containing functional groups was observed on the surface of composite samples treated in an oxygen plasma. These plasma‐treated samples also showed differences in surface topography, but no change in the photoacoustic infrared spectra when compared to a methanol‐washed sample.
The deconvolution of sputter‐etching surface concentration measurements to determine impurity depth profiles
Authors: Carter G. , Katardjiev I. V. , Nobes M. J. 
Published: December 2004

AbstractThe quasi‐linear partial differential continuity equations that describe the evolution of the depth profiles and surface concentrations of marker atoms in kinematically equivalent systems undergoing sputtering, ion collection and atomic mixing are solved using the method of characteristics. It is shown how atomic mixing probabilities can be deduced from measurements of ion collection depth profiles with increasing ion fluence, and how this information can be used to predict surface concentration evolution. Even with this information, however, it is shown that it is not possible to deconvolute directly the surface concentration measurements to provide initial depth profiles, except when only ion collection and sputtering from the surface layer alone occur. It is demonstrated further that optimal recovery of initial concentration depth profiles could be ensured if the concentration‐measuring analytical probe preferentially sampled depths near and at the maximum depth of bombardment‐induced perturbations.
Quantification of SIMS on titanium carbides
Authors: Brault G. , Moncoffre N. , Pivin J. C. , Rautureau G. 
Published: December 2004

AbstractIon implantation and Rutherford backscattering are combined to study:

the effects of caesium doping and caesium bombardment on SIMS emission yields,
the carbon emission yield as a function of its concentration in Ti1−xCx films. Quantitative analysis by SIMS of such films can be performed with an accuracy of 5%.
Measurements of the magnitude of crystalline effects in Auger electron spectroscopy
Authors: Bishop H. E. 
Published: December 2004

AbstractDiffraction of both the primary electron beam and the excited Auger electrons are known to have an influence on the measured peak intensities in Auger electron spectroscopy (AES). In this work, crystalline effects have been measured for a number of single‐crystal materials under conditions commonly used for AES, in an ESCALAB Mk II (VG Scientific, Ltd) fitted with a goniometer stage. Large variations in Auger peak intensity with crystal orientation were observed, reflecting both the symmetry and structure of the surface. It is shown that under normal operating conditions the diffraction of the primary electron beam is mainly responsible for the observed intensity variations but that diffraction of the Auger electrons cannot be neglected entirely. The significance of crystalline effects to quantitative AES is discussed.
Energetics of nickel and palladium
Authors: Finley C. W. , Ferrante J. 
Published: December 2004

AbstractWe present several model calculations involving nickel and palladium using the embedded atom method. Adhesion in the crystalline form of these substances is studied by calculating surface energy as a function of separation of a solid along a crystalline plane, and slip barrier height as a function of displacement. We also investigate a bulk property, Poisson's ratio, as a function of tensile strain. In addition, we examine the equilibrium configuration of metal clusters by finding the minimum energy configuration of clusters consisting of a small number (N = 2–6) of nickel atoms.
An Auger sputter profiling study of nitrogen and oxygen ion implantations in two titanium alloys
Authors: Barton B. D. , Pope L. E. , Wittberg T. N. 
Published: December 2004

AbstractSamples of two titanium alloys, Ti–6Al–4V and Ti–15V–3Cr–3Sn–3Al, were ion implanted with a combination of nitrogen (N+) and oxygen (O+). For each alloy, implantation parameters were chosen to give implanted nitrogen concentrations of ∼10 or 50 at.%, from a depth of 100 nm to a depth of 400 nm. In all but one case, dual energy (200 keV and 90 keV) implantations of nitrogen were used to give a relatively uniform nitrogen concentration to a depth of 300 nm. In each case, oxygen was implanted at 35 keV, following the nitrogen implantation, to give an oxygen‐enriched region near the surface. The implanted samples were then examined by Auger electron spectroscopy (AES) combined with argon ion sputtering. In order to determine the stoichiometry of the nitrogen‐implanted regions, it was necessary to determine the N KVV contribution to the overlapping N KVV and Ti LMM Auger transitions. It was also necessary to correct for the ion‐bombardment‐induced compositional changes that have been described in an earlier study of titanium nitride thin films. The corrected AES depth profiles were in good agreement with theoretical predictions.
Aluminum surface mobility on two types of silicon oxide during ionized cluster beam deposition
Authors: Levenson L. L. , Swartzlander A. B. , Usui H. , Yamada I. 
Published: December 2004

AbstractAn ionized cluster beam (ICB) source was used to deposit A1 onto two types of silicon oxides. One was a thermal oxide generated by steam oxidation of Si at 900°C. The other was a P‐doped oxide deposited on Si at 425°C. During Al deposition, 60 μm diameter wires were held at the substrates to serve as masks. After A1 deposition, the wires were removed and the masked areas were examined by scanning electron microscopy (SEM) and by scanning Auger microprobe (SAM). The ICB source was operated at 0, 3 and 6 kV accleration voltages. The substrates were held at 80, 200 and 400°C during A1 depositions. The A1 deposition rate averaged 24 nm min.−1 The chamber pressure during deposition was 3 × 10−4 Pa. The diffusion distance of A1l under a mask edge was determined from the SEM micrographs and SAM line scans. The maximum diffusion distance occurred at 200°C for both substrates, with the exception of the 0 kV A1 beam deposited on the low‐temperature oxide (LTO). On the high‐temperature oxide (HTO), the maximum diffusion distance was 29 μm at 6 kV acceleration voltage. The minimum diffusion distance was 8 μm at 70–80°C on the LTO for acceleration voltages of 0 and 3 kV.
XPS study of the Y/SiOx interface at room temperature
Authors: Reichl R. , Gaukler K. H. 
Published: December 2004

AbstractThe reducing reaction of vapour‐deposited yttrium layers on silicon oxide was measured by XPS at room temperature. The redox reaction was confined essentially to the deposition period. The thickness of the insulating SiOx layer decreases by ∼0.2–0.3 nm. No further reaction during the 8 h following deposition could be observed.
In situ X‐ray photoelectron spectroscopy of surfaces at pressures up to 1 mbar
Authors: Ruppender H. J. , Grunze M. , Kong C. W. , Wilmers M. 
Published: December 2004

AbstractIn this article we describe an x‐ray photoelectron spectrometer that can either be used as an ultra‐high vacuum instrument (p < 10−10 mbar) or, after insertion of a movable aperture, to analyse materials at ambient pressures up to 1 mbar. We will describe the basic design of the instrument, and the methods used to determine the pressure at the location of photoelectron ejection. One way to estimate the pressure is by attenuation of the substrate signal by the gas phase and comparing experimental with published ionization cross‐sections; the second method uses condensation isobars. Examples are given for gas‐phase spectra. Application of the instrument in surface science studies is demonstrated by two examples where surfaces were analysed under high‐pressure conditions as a function of temperature, showing that the instrument allows steady‐state equilibrium measurements of surface composition.
Method for the alignment of samples and the attainment of ultra‐high‐resolution depth profiles in Auger electron spectroscopy
Authors: Hunt C. P. , Seah M. P. 
Published: December 2004

AbstractThe need to align the electron beam, the electron spectrometer axis and the ion beam all at the same point on the sample surface in sputter‐depth profiling using Auger electron spectroscopy is crucial to the attainment of efficient high‐resolution profiles. In this study we develop a method that allows these axes to be set to ±25 μm in concentric hemispherical analyser systems. Then, using the coincidence of the electron beam and spectrometer axes, samples may be repositioned repeatedly to ±25 μm and the point of analysis on the sample to within ±40 μm of the centre of the ion‐sputtered crater. The method is illustrated in the characterization of a second batch of tantalum pentoxide on tantalum reference material. New resolutions of 1.51 and 1.60 nm are achieved for the 31.1 and 95.8 nm thick oxides, respectively, when using the standard conditions of 2 keV argon ions and monitoring the oxygen Auger electrons. If the ion energy is reduced to 1.5 keV and the tantalum low‐energy peaks are used, the resolution for the 95.8 nm oxide may be reduced to 0.82 nm.
XPS determination of the thickness of adsorbed mouthrinse components on dental enamel
Authors: Busscher H. J. , Van der Mei H. C. , Genet M. J. , Perdok J. F. , Rouxhet P. G. 
Published: December 2004

AbstractIn this paper, the stationary charging voltage of human dental enamel samples due to photoelectron ejection in an x‐ray photoelectron spectrometer is related to the amount of material adsorbed from commercially available mouthrinses and the adsorbed layer thickness. A clear relationship was observed between the charging voltage versus the C/Ca elemental surface concentration ratio, taken as a measure of the amount of adsorbed material. Consequently, a similar relationship was found between charging versus adsorbed layer thickness.
Contributions of surface analysis to corrosion science: Selective dissolution and oxidation phenomena in alloy corrosion
Authors: Landolt D. 
Published: December 2004

AbstractThe role for corrosion kinetics of corrosion‐induced surface composition changes on alloys is discussed and illustrated with surface analytical (AES, XPS, SIMS) and electrochemical (polarization behaviour) results from the author's laboratory. In situ oxidation of FeCrMo alloys, anodic dissolution in the active state of binary noble metal alloys (AgPd) and anodic dissolution in the passive state are compared. It is shown that selective oxidation and dissolution phenomena and differences in the transport rate of cations in thin oxide films control the chemical composition of the surface region and thus greatly affect the corrosion rate.
The effect of atomic‐scale etch pit formation on depth resolution in sputter profiling
Authors: Carter G. , Nobes M. J. , Katardjiev I. V. 
Published: December 2004

AbstractA very simplified model of atomic‐scale etch pitting during sputtering erosion for composition depth profiling is used to modify the Benninghoven–Hofmann approach to layer‐by‐layer sputtering. It is shown that analytically tractable defining equations result, with solutions that indicate that etch pitting slightly worsens depth resolution as the probability of producing deep etch pits increases.
The ageing of Li implants in cadmium mercury telluride
Authors: Blackmore G. W. , Courtney S. J. , Astles M. G. , Shaw N. 
Published: December 2004

AbstractSecondary ion mass spectrometry (SIMS) requires the preparation and measurement of standard samples in order to be considered a quantitative technique. This normally can be achieved by the production of ion‐implanted specimens in the matrix to be studied. The measured SIMS depth profile then can be integrated and compared with the known implanted dose in order to produce quantitative results. This paper reports a potential source of error in this method, discovered by studying the ageing of a lithium‐implanted cadmium mercury telluride (CMT) specimen over a six‐year period. Lithium has been shown to be a mobile impurity in CMT.It is shown that the original implant produced a satisfactory profile shape, but that room‐temperature diffusion subsequently degraded its shape over a period of five years. This finding is confirmed by the further action of annealing the implanted specimen at 250°C and studying the resulting profile. The change in the shape of the implant profile is discussed in relation to diffusion theory. SIMS images are shown to demonstrate the spatial inhomogeneity of the sample.
Depth analysis of nickel thin films on silicon by glow discharge spectroscopy: The interface region
Authors: Weiss Zdeněk 
Published: December 2004

AbstractDepth profiles of nickel thin films on silicon obtained with a Grimm glow discharge lamp operating at various conditions were compared. The best conditions for the profile analysis are: high argon pressure, high discharge current and low discharge voltage. The signal response at the interface was described quantitatively using piecewise linear model functions. Influence of the discharge parameters on the signal response at the interface was discussed. Interface broadening was confirmed to be caused by the crater effect, with a non‐uniform removal rate distribution across the analysed spot that does not depend on the total sputtered depth in the analysis of a homogeneous sample.