bluuebunny/crossref_metadata_2025_split huggingface dataset:
A time‐of‐flight study of water molecular ion and neutral scattering from copper surfaces
Authors: Xu N. S. , Pearce C. G. , Sullivan J. L. 
Published: May 2005

AbstractCollision of water molecule ions with solid surfaces can result in neutralization and fragmentation of the molecule. The energy distribution of total scattered yield was measured with a time‐of‐flight mass spectrometer. The major spectral peak energy is close to the value expected for a binary collision of OH with a copper atom, and the energy distribution can be accounted for by the existing dissociation models. Comparisons are made between the scattering of water molecule ions and that of He+ and Ne+ ions in terms of the spectral full width at half‐maximum, shape and the scattered yield. It is found that significant water vapour neutral peaks appear in the spectra of scattered Ne. This implies that strong non‐resonance charge exchange mechanisms occur in the projectile beams. The spectral peak heights of the water ion and neutral scattered at different incident angles are compared to those of Ne.
Determination of ultrathin film growth modes using inelastic Auger electrons: Sm/Cr (211)
Authors: Dubot P. , Barthés‐Labrousse M. G. , Langeron J. P. 
Published: May 2005

AbstractA new method for the characterization of ultrathin films adsorbed onto clean metal crystals is proposed by monitoring the variation of the substrate peak‐on‐tail (P/T) ratio in the direct Auger spectrum as a function of adsorbate deposition time. Because the inelastic tail on the low‐ energy side of the Auger peak is strongly dependent on the in‐depth concentration of the emitting atoms, a comparison of the experimental P/T values with computational simulations based on a numerical layer‐by‐layer model allows determination of the adsorbate and substrate indepth distribution, thus giving some insight on the growth mode. We have used this technique to follow the adsorption of Sm onto a Cr(211) surface at 300 and 900 K. Comparison has been made with the results obtained when monitoring variations of the Auger peak‐to‐peak heights as a function of adsorbate deposition time in the derivative spectrum (AS–t plots). At 300 K, both methods clearly show evidence of the formation of a dense Sm monolayer followed by three‐dimensional crystallites (Stranski–Krastanov growth mode). At 900 K, the AS–t plots do not allow discrimination between the formation of a CrSm surface compound and a pure low‐density Sm overlayer. By using P/T ratios, the formation of a surface compound can be set aside in favour of a pure Sm monolayer with a density approximately equal to half the density of a close‐packed Sm overlayer.
Hydration of oxide films on aluminium and its relation to polymer adhesion
Authors: Thorne N. A. , Thuéry P. , Frichet A. , Gimenez P. , Sartre A. 
Published: May 2005

AbstractIn the flexible packaging industry, aluminium foil is used to fabricate metal–polymer complex systems without any prior surface treatment (e.g. anodic oxide, chemical conversion coating). The inevitable delay between foil rolling and subsequent application of the polymer, in this case polyethylene, allows ageing of the aluminium oxide to occur, which may significantly reduce the adhesion strength of the metal/polymer joint.To enable a better understanding of the ageing phenomena occurring and hence to improve the industrial control of the key parameters, controlled ageing of mini‐coils of a 1200 aluminium alloy has been performed in H2O and D2 atmospheres, with some material being subsequently stored under dry conditions. The resultant hydration of the surface oxide has been followed by XPS, SIMS and electrochemical impedence spectroscopy (EIS).The combination of XPS and EIS indicates that loosely bound physisorbed water, partly removed by dry storage, plays a key role in the adhesion strength of the metal/polymer joint. SIMS imaging of deuterium incorporated in the film as Al(OD)3 shows clearly the heterogeneous nature of the hydration process, with preferential sites being associated with iron‐rich intermetallic phases. For storage periods of >50 days, the formation of these friable bayerite islands predominates and will cause catastrophic loss of adhesion. For shorter periods, however, the loosely bound water plays a major role, and its reversible nature points to the possibility of at least partial recovery of the joint strength by dry storage of the foil prior to application of the polymer.
Influence of plasma pretreatment of polypropylene on the adhesion with aluminium: An Auger spectroscopic study
Authors: André V. , Arefi F. , Amouroux J. , Lorang G. 
Published: May 2005

AbstractThe adhesion of polypropylene (PP) films with respect to an aluminium coating has been improved with the help of a non‐equilibrium plasma process, and the metal layer is deposited in situ immediately after pretreatment. Elsewhere, with the help of many complementary surface analyses (XPS, ISS, static SIMS), the modifications created by plasma treatment on the non‐metallized polymer have been explained partially. In this paper, the aluminium/PP interface has been studied by AES. The problems encountered during analyses of the metallized films are mentioned, which lead to the definition of the polymer–metal interface. It has been shown that independently of the pretreatment carried out on the polymer, the interface consists of an oxidized film of ∼4 nm thick. Furthermore, the role of the experimental conditions of the Auger analyses on the obtained profiles has been studied and discussed.
Surface and microanalytical studies on the corrosion of a Ti5Ta alloy in concentrated nitric acid
Authors: Eickmans J. , Holm R. , Müller G. , Horn E.‐M. , Droste R. 
Published: May 2005

AbstractThe Ti5Ta alloy shows interesting corrosion behaviour and is becoming technologically important, e.g. for chemical plant construction. Welding and further mechanical tests gave good mechanical properties. Therefore, the corrosion of this alloy was studied in comparison with the corrosion of unalloyed Ti and Ta. The samples were corroded for up to 24 days in hot 67.5% nitric acid.The resulting surface layers were investigated with SEM, transmission electron microscopy (TEM), energy dispersive x‐ray microanalyses (EDX), AES and sputtered neutral mass spectrometry (SNMS). Under these conditions, the oxide growth seems to be dependent on the orientation of the crystallites at the surface, which was not observed under milder attack. When Ti5Ta samples were immersed for 5 days in boiling HNO3, the oxide layer was ∼300 nm thick and a particular crack pattern developed on some grains during drying in air at room temperature. This was observed only for oxide layers thicker than 300 nm.After corroding Ti5Ta in boiling HNO3 we observed a TaTi atomic ratio of up to 1:1 using ESCA and up to 5 μm thick Ta oxide‐rich scales. The selected area diffraction pattern in the TEM indicates that the oxide film may contain mixed Ti/Ta oxides. The extraordinary Ta oxide enrichment, which is due to the selective dissolution process of Ti, is believed to cause the good corrosion resistance of the alloy. It was not observed after heat treatment in air up to 800 °C or after corrosion tests in HNO3 at room temperature.
In‐depth profiling of hydrogen in oxidic multilayer systems
Authors: Wagner W. , Rauch F. , Ottermann C. , Bange K. 
Published: May 2005

AbstractThe hydrogen concentration profiles of electrochromic multilayer systems produced by evaporation have been determined by means of nuclear reaction analysis. The H content of individual oxidic materials was found to be larger than for single films, especially for SiO2. The time‐dependent H uptake under various ambient conditions was investigated. Systems produced by ion plating were also profiled for hydrogen.
The preparation and characterization of a model supported ruthenium catalyst
Authors: Aas N. , Sakakini B. H. , West R. H. , Vickerman J. C. 
Published: May 2005

AbstractA model supported ruthenium catalyst was prepared by sputter depositing the metal onto a thin alumina film that had been formed by anodic oxidation of aluminium foil. The metal loading could be varied by changing the time of sputtering, and in this way the growth of the metal was investigated with XPS. Static SIMS combined with temperature‐programmed desorption (TPD) was used to study CO adsorption and to evaluate the metal–gas bonding, as well as the metal–oxide interaction.
Surface characterization of plasma‐treated PTFE
Authors: Morra M. , Occhiello E. , Garbassi F. 
Published: May 2005

AbstractPTFE was treated with oxygen and argon plasmas and the effects of treatment were evaluated by actinometry, SEM, XPS, static SIMS and contact angle measurements. At short treatment times for both plasmas and at long treatment times for argon plasmas, chemical modification of the surface was dominant, while at longer oxygen plasma treatment times, surfaces are deeply etched but chemically equivalent to untreated PTFE. Interestingly, the change in surface chemistry is paralleled by a simultaneous variation in plasma chemistry, suggesting that the two vary accordingly. The wetting behaviour of treated surfaces is interopreted on the basis of current theories on surface dynamics and contact angle hysteresis.
Application of X‐ray emission spectrometry (LEEIXS) to the study of insulator surface—molecular characterization of some metallic oxides or compounds
Authors: Gaillard F. , Romand M. 
Published: May 2005

AbstractLow‐energy electron‐induced x‐ray spectrometry (LEEIXS) is a soft and ultrasoft x‐ray emission technique. The wavelength‐dispersive x‐ray spectrometer used is equipped with a cold cathode tube. This device acts as an excitation source by bombarding the sample surface with a quasi‐monoenergetic electron beam, the energy of which is selectable over the range from 0.5–5 keV. The probed depth, depending among other parameters upon the incident electron beam energy and upon the sample nature, typically ranges from 5 to 150–200 nm, the probed area being ∼1 cm2. The capabilities of this technique in the fields of atomic and molecular surface analyses have been shown for a wide range of applications. The aim of this paper is to point out the ability of this technique to solve some problems dealing with the near‐surface analysis of insulating materials and, more particularly, of some metallic oxides.
Defect formation observed by AES in a‐SiO2 films prepared by photochemical vapour deposition
Authors: Nonaka H. , Ichimura S. , Arai K. , Le Gressus C. 
Published: May 2005

AbstractDamageless conditions in AES measurement were examined carefully on both thermally oxidized and photochemical vapour deposited amorphous SiO2 films as a function of dose rate and total dose. The lower dose rate resulted in the formation of a higher density of oxygen‐deficient defects under the constant total dose condition. Among the films examined, it was found that F‐doped films prepared by photochemical vapour deposition best resisted electron damage. The results are discussed using the model of defect generation consisting of a cascade process, bond breaking and diffusion of oxygen.
A third‐generation Auger microscope using parallel multispectral data acquisition and analysis
Authors: Prutton M. , Walker C. G. H. , Greenwood J. C. , Kenny P. G. , Dee J. C. , Barkshire I. R. , Roberts R. H. , El. Gomati M. M. 
Published: May 2005

AbstractThe Design and construction of an ultrahigh vacuum multi‐imaging scanning electron microscope is described. The microscope is designed to contain two field electron emission columns and can acquire simultaneous digital images from a 16‐channel electron spectrometer, a four‐quadrant back‐scattered electron (BSE) detector, an Si(Li) x‐ray detector, a SEM detector and the current flowing to ground through the sample. Because there is exact spatial registration between corresponding pixels in each of the images, it is possible to use the image set to make quantitative interpretations of the surface and subsurface chemistry. This is done using mathematical manipulations of the image set, together with models for the SEM, BSE and Auger signals. Techniques are described for setting up the alignment and characterizing the field of view and transmission function of the microscope and its spectrometer. Examples of multi‐imaging from simple samples are given. The close coupling between the microscope and its control and interpretation computers provides considerable power for the analysis of inhomogeneous surfaces.
Curve synthesis and optimization procedures for X‐ray photoelectron spectroscopy
Authors: Evans Stephen 
Published: May 2005

AbstractThe selection of functions to represent XPS lineshapes is discussed. An improved Lorentzian/Gaussian product function is proposed for fitting symmetrical XPS peaks, and a further empirical modification is shown to represent asymmetric (metallic) XPS peak profiles very closely. One additional parameter sets the asymmetry at half‐height, while a second governs the tail profile.An approach to curve synthesis that rapidly yields good first approximations to complex multicomponent spectra is described. Previous fits to model systems may be incorporated, and background intensity differences between the high‐and low‐energy sides of each model peak may be retained in the fit.A simple least‐squares optimization procedure is described in which divergence is impossible but which is still sufficiently fast for microcomputer implementation. Physically desirable parameter constraints can be applied, and excessively large parameter changes are prevented, even for small components of the fit. The relative precisions of the computed parameters also estimated.
New glow discharge lamp with Co–axially–arranged dual hollow anodes
Authors: Morita Hiromi , Wagatsuma Kazuaki , Hirokawa Kichniosuke 
Published: May 2005

AbstractA glow discharge lamp consisting of two hollow anodes set co‐a‐axially has been developed to attempt to improve the resolution at interfaces in depth profiling. The structure and the operating conditions of the lamp are described. In addition, an in‐depth analysis of Fe/Zn layers on steel plates has been attempted with this glow lamp. Compared to a conventional glow lamp, the measurements can be performed with improved depth resolution.
The effects of photoelectron diffraction on quantitative X‐ray photoelectron spectroscopy
Authors: Bishop H. E. 
Published: May 2005

AbstractAlthough not discussed in most reviews of quantitative x‐ray photoelectron spectroscopy (XPS), diffraction of the photoelectrons leaving a single crystal can lead to potential errors of a factor of two or more in the calculated surface composition. A series of experimental measurements has been made to demonstrate the magnitude of the diffraction effects. These results are used as the basis for a discussion of the influence of crystalline effects on quantitative XPS. If the full solid angle of modern electron spectrometers is used, the potential errors are relatively small and can be minimized by adopting suitable procedures. If the acceptance angle of the analyzer is restricted for angular‐resolved or for small‐area measurements, the potential errors are substantial and great care is required to avoid them.
Topographical contrast using scatter diagrams and correlated images form four backscattered electron detectors
Authors: Barkshire I. R. , El Gomati M. M. , Greenwood J. C. , Kenny P. G. , Prutton M. , Roberts R. H. 
Published: May 2005

AbstractThe York multi‐spectral Auger electron microscope has been used to examine the correlations between four images measured simultaneously by collecting energetic backscattered electrons (BSEs) with four quadrants of an Si p‐n junction BSE detector. Digital signal processing of the four images reveals the topography expected of the polyhedra on the surface of an Ag‐coated, anisotropically etched Si sample. Scatter diagrams formed form the pair of topographical images appear as distorted stereographic projections of the distribution of local surface normals. The use of such projections via models of the scattering process is proposed as a means of correcting topographical artifacts in Auger, EDX and other chemically specific images.
Image correlation: Application to correction of beam current fluctuations in quantitative surface microscopy
Authors: Barkshire I. R. , Greenwood J. C. , Kenny P. G. , Prutton M. , Roberts R. H. , El Gomati M. M. 
Published: May 2005

AbstractThe York multi‐spectral Auger microscope has been used to demonstrate the use of the anticorrelation between a SEM and a sample current image fluctuations. Such fluctuations may be important when using very bright electron sources or when collecting image data over long periods of time.
Maximum likelihood common factor analysis in Auger electron spectroscopy
Authors: De Volder P. , Hoogewijs R. , De Gryse R. , Fiermans L. , Vennik J. 
Published: May 2005

AbstractAn advanced multivariate statistical technique, maximum likelihood common factor analysis (MLCFA), is proposed as an alternative method to principal component analysis (PCA). From a critical review of both methods, it is shown that MLCFA is superior by far to PCA for decomposing overlapping peaks into their component spectra since it is not subject to the various arbitrary factors that characterize the PCA procedure and since it requires less a priori information about the system under study. Investigation of computer‐simulated sets of related spectral mixtures that simulate a series of background‐corrected Auger spectra in a depth profile confirms that, compared to PCA, MLCFA leads to an improved determination of the correct number of relevant components. When treating real Auger spectra, a correct interpretation of the experimental background, ion sputtering effects, etc. is necessary, as discussed previously in the literature. The present results, however, indicate that the implementation of MLCFA in the field of Auger electron spectroscopy contributes substantially to the correct characterization of the chemical composition of solid surfaces and interfaces.
Quantitative analysis of W(N), TiW and TiW(N) matrices using XPS, AES, RBS, EPMA and XRD
Authors: Alay J. L. , Bender H. , Brijs G. , Demesmaeker A. , Vandervorst W. 
Published: May 2005

AbstractThe structural and quantitative chemical analyis of tungsten nitrides and titanium–tungsten nitrides with variable N content (denoted as W(N) and TiW(N)) are explored by a combination of different analysis techniques. Special attention is given to the unraveling by XPS of the different binding states that are present in the surface contamination layer and in the bulk of the layers. The determination of our own sensitivity factors is essential for accurate quantification of both XPS and AES data. Comparison of the different techniques shows the presence of strong preferential sputtering for W(N) alloys, whereas this effect is unimportant for TiW(N). The influence of the vacuum of the analysis chamber of XPS and AES on the results is studied thoroughly.
Interfacial chemistry and adhesion: The role of surface analysis in the design of strong stable interfaces for improved adhesion and durability
Authors: Cayless R. A. 
Published: May 2005

AbstractDurability is a key issue in widening the application of adhesive bonding technology. This paper describes a fundamental study of the adhesion loss in epoxy‐steel bonds exposed to water, and the development of steel pretreatments, which significantly enhance durability. XPS studies have revealed two weak links in epoxy/steel bonds, both of which must be improved for optimum performance. They are displacement of the adhesive from the steel and breakdown of the oxide on the metal surface. The former has been addressed by applying monomolecular layers of an aminosilane adhesion promoter to the steel surface. Oxide instability has been remedies by use of a novel and simple treatment that modifies the oxide chemistry to a depth of 2–5 nm. Combining these, results in a joint that loses no strength after 2000 h of water immersion at 50°C, whereas untreated joints lose 68% of their strength after only 400 h. The study shows how careful identification of failure modes, combined with appropriate modification of the substrate surface, can be used to design strong stable interfaces. These modification, which affect only a few molecular layers, have a large impact on both bond strength and durability.
The effect of surface pretreatment on carbon fibre–polyimide matrix composite bonding
Authors: Moyer Denise J. D. , Wightman J. P. 
Published: May 2005

AbstractThe single lap shear test and the wedge test were used to evaluate the effect of surface pretreatment on the strength and durability of adhesively boned composite joints. Both types of joints were placed in three different environments: (1) room temperature, desiccator, 1000 h; (2) 204°C, 1000 h; (3) immersion in boiling water for 3 days for the single lap shear test and until failure for the wedge test. The failure surfaces were analyzed using XPS to determine the locus of failure. An oxygen plasma was found to be the best pretreatment. The improvement in adhesive bonding following exposure to an oxygen plasma in comparison to the other surface pretreatment was attributed to several factors—a reduction in fluorocarbon contamination caused better wetting of the composite surface and also may lead to covalent bonding at the composite/primer interface.
Fracture mechanisms of the fiber/matrix interfacial bond in fiber‐reinforced polymer composites
Authors: Latour Robert A. , Black Jonathan , Miller Bernard 
Published: May 2005

AbstractThe fracture behavior of the fiber/matrix interfacial bond is an important governing factor of both composite fracture behavior and its environmental resistance. Methods have been developed to investigate the ultimate and dynamic fatigue fracture behavior of the interfacial bond in both a dry and a saline environment at 37°C. a single fiber embedded within a thermoplastic microdroplet pull‐out test was used as the sample model for this work. Ultimate bond strength testing was conducted on a CGS mechanical test machine while fatigue testing was conducted on a custom‐built miniature closed‐loop mechanical test machine designed to apply accurately controlled dynamic loads to test samples within the range 0.000–0.200 N. The fracture behavior of the interfacial bonds formed between polysulfone thermoplastic and both carbon fiber and polyaramid fiber were investigated using these methods. Results show that the ultimate and fatigue strength of the carbon fiber/polysulfone interface is significantly greater than the polyaramid fiber/polysulfone interface in both the dry and saline invironments. The ultimate and fatigue strengths of the interfaces of both sample types were significantly lower in the saline environment compared to the dry condition. Evaluation of interfacial bond fracture surfaces by SEM indicated that interfacial bond fracture occurred by a combination of both interfacial adhesive and matrix cohesive failure. Results indicate that matrix cohesive failure occurs as a function of both the absolute magnitude of the applied interfacial shear stress and its value relative to the ultimate strength of the interface.