bluuebunny/crossref_metadata_2025_split huggingface dataset:
Acid–base interactions at carbon fibre/PEEK interfaces
Authors: Nardin M. , Asloun E. M. , Schultz J. 
Published: May 2005

AbstractThe stress transfer from the matrix to the fibre in composite materials depends to a large extent on the level of adhesion between these materials. In the present study, the work of adhesion between carbon fibres and PEEK polymer is estimated from the surface characteristics of the fibre and the matrix and, more precisely, from the dispersive component of the surface energy and the acid–base character of both material, determined by inverse gas chromatography at infinite dilution.The interfacial shear strength at the carbon fibre/PEEK interface is measured also by means of a fragmentation test on the respective single‐fibre composites.For PEEK polymer, it is shown that the acid–base characteristic of fibres and powder are different, indicating that the orientation of the macromolecules near the surface may be affected by the processing of such materials. Nevertheless, as already shown in previous studies for other systems, a linear relationship between the interfacial shear strength and the adhesion at the fibre/matrix interface can be established.
Surface study of polycarbonate membranes used as a substratum for animal cell culture
Authors: Dewez Jean‐Luc , Deren Aurora , Rouxhet Paul G. , Schneider Yves‐J. , Legras Roger 
Published: May 2005

AbstractThe aim of this work is to investigate the relationships between the chemical composition of a polymer surface and its physico‐chemical properties. The study of track‐etched membranes was undertaken in order to understand and control better the attachment of epithelial cells for reconstituting a highly differentiated cell tissue.The bis‐phenol A polycarbonate membrane surface properties have been modified by various procedures: sulphochromic acid, nitration, oxygen and ammonia radio frequency (rf) glow discharge, corona discharge. The surface chemical composition was determined by x‐ray photoelectron spectroscopy and the surface free energy was computed from the contact angle of various liquids.The presence of sulphur and nitrogen‐containing groups bound to the surface has been demonstrated after application of the corresponding wet surface treatments. All surface treatments lead to an increase of the oxygen surface concentration, the highest value being obtained after nitration. As a result, the polar contribution to the surface free energy also is increased; this seems to be correlated with the surface concentration of oxygen bearing a high electron density.The cell adhesion and growth on the membranes is improved by the surface treatments applied, in particular by oxygen rf glow discharge. However, steam sterilization tends to remove the effects of earlier surface modification; this seems to be more pronounced when the sample is in direct contact with liquid water.
Fractured interface characterization of epoxy‐bonded steel joints
Authors: Dodiuk H. , Kenig S. 
Published: May 2005

AbstractCharacterization of epoxy–maraging steel failure interface was carrier out using SEM/EDAX, Auger and FTIR spectroscopies. The steel surface was either sand blasted and/or treated in superheated steam (SHS) prior to epoxy bonding. Acetone wipe served as a reference. Experimental results showed that sand blasting is necessary prior to SHS treatment to avoid premature oxide–steel interfacial failure. In opening crack‐type wedge specimens, the interfacial failure that appears visually to be interfacial in nature, is really a mixed mode type failure as indicated by EDAX analysis and Auger spectroscopy. FTIR indicated that SHS treated maraging steel is superior, with respect to resistance of water absorption, when the bonded wedge specimens have been exposed to high humidity.
Interfacial layers and adhesion in the moulding of nitrile rubber
Authors: Lotfipour M. , Packham D. E. , Turner D. M. 
Published: May 2005

AbstractThe mould release of rubber gives a good example of circumstances where a consistent but low level of adhesion is of importance.In this paper, XPS work on mould release of rubber is described, and the influences on the adhesion of nitrile rubber to moulds are discussed.Two tests of adhesion have been developed, the ‘TMS’ rheometer and the blister test. XPS has been used to characterize the interfaces after separation.The fracture path during demoulding is close to the interface between the alloy and the polymer, within a layer consisting of residues such as coagulants and emulsifiers from the initial polymerization. Thus, the level of adhesion depends upon the nature of this layer formed at the interface during moulding.
Separation of spectral components and depth profiling through inelastic background analysis of XPS spectra with overlapping peaks
Authors: Hansen H. S. , Tougaard S. 
Published: May 2005

AbstractA Method for simultaneous separation and quantitative analysis of overlapping XPS spectral components originating from two different elements has been developed. The method is based on a detailed theory for electron transport in solids and involves deconvolution of the inelastic spectral background from the surface electron spectra. The method is tested through analysis of model spectra of adsorbate/substrate systems following the Frank–van der Merwe, the Stranski–Krastanow or the Volmer–Weber modes of growth. It is demonstrated that the total amount of adsorbate can be found from one single spectrum with an error of ⩽ 10% independent of t he mode of growth. In addition, the method gives information on the structural properties of the adsorbate and its mode of growth, with a resolution of the order of the inelastic mean free path.
In situ FTIR study of ethyl xanthate adsorption on gold, silver and copper electrodes under controlled potential
Authors: Talonen P. , Rastas J. , Leppinen J. 
Published: May 2005

AbstractThe applicability of a spectroelectrochemical method to the problems related to flotation was studied. The object of the study was to investigate the adsorption of ethyl xanthate on gold, silver and copper surfaces. Spectra were obtained using subtractively normalized interfacial Fourier transform infrared spectroscopy, which allows potential control of electrode while recording an infrared spectrum at the electrode surface. For each metal, a good correlation exists between the spectral intensities of the product of the surface reaction and the voltammogram of the metal electrode immersed in xanthate solution. On gold, xanthate is oxidized to dixanthogen, which is then adsorbed onto the gold surface. In the case of both silver and copper, xanthate reacts with the surface in two separate steps. The first comprises chemisorption of xanthate, the result being a monolayer of metal xanthate‐like surface compound. The second, more anodic, step is the formation of multilayers of metal xanthate.
Microcalorimetric and EGA study of germanium surfaces interacting with different gases
Authors: Stradella Luigi 
Published: May 2005

AbstractAn investigation of the adsorption of several vapours and gases (ammonia, water hydrogen, carbon dioxide, oxygen, carbon monoxide, nitrogen, dinitrogen oxide, propene) on polycrystalline germanium has been carried out at 305 K, in the pressure range between 1 × 10−4 Pa and 20 kPa, using a Tian‐Calvet microcalorimeter.Water, ammonia, hydrogen and carbon dioxide apart, the adsorption is physical and fully reversible. The Calometric data suggest a dissociative chemisorption for hydrogen and a strong coordinative bond of water and ammonia with more active surface sites.Evolved gas analysis experiments have been performed on the same sample in the range 300–1000 K, focusing on the H2–Ge, H2O–Ge and N2O–Ge systems. Temperature‐programmed mass spectra desorption mass spectra indicate that 700 K is the optimum temperature for H2O dissociation, while at 550 K there is a maximum in H2 chemisorption; as with the decomposition of N2O, a strong adsorption on the semiconductor of all the species present at the interface strongly interface with the chemical equilibrium.
XPS study of the Sc/SiOx interface at room temperature
Authors: Reichl R. , Gaukler K. H. 
Published: May 2005

AbstractThe reducing reaction of vapour‐deposited scandium layers on silicon oxide at room temperature has been investigated using XPS. The redox reaction took place during the deposition period and diminished the thickness of the silicon oxide layer by ∼ 0.3 nm. No further reaction during the 8 h following deposition was detected.
Quantitative trace analysis by non‐resonant laser post‐ionization
Authors: Hayashi S. , Hashiguchi Y. , Suzuki K. , Ohtsubo T. , McIntosh B. J. 
Published: May 2005

AbstractIn order to overcome the poor quantitativeness of conventional SIMS, sputtered neutral mass spectrometry (SNMS) employing non‐resonant laser post‐resonant laser post‐ionization has been studied. By studied. By combining a time‐of‐flight (TOF) analyzer with a powerful excimer laser, it was confirmed that non‐resonant laser post‐ionization is capable of quantitative analysis of impurities at the pm level. On comparing laser wavelengths, 193 nm (ArF) gave a higher post‐ionization efficiency than 248 nm (KrF). It was also demonstrated that the electronegative element sulphur can be detected as positive ions by post‐ionization. Furthermore, surface metallic contaminants in a small area (250 μm square) could be determined down to 1011 atoms cm−2.
Recent development in quantitative XPS in the USSR
Authors: Nefedov V. I. 
Published: May 2005

AbstractA review of the recent theoretical and practical achievements in quantitative XPS in the USSR is presented. The following items are discussed: theoretical development—determination of in‐depth profiles on the basis of angular dependences of ESCA intensities, correction for contamination layer, quantitative characterization of the supported particles, determination or calculation of some physical parameters (photoionization) cross‐section, photoelectron mean free paths, (line shapes); practical application of quantitative ESCA surface analysis—high‐temperature superconductors, oxidation of alloys and metals, fluorination of alloys and metals, amorphous alloys, catalysts, semiconductors and related systems, oxides and related systems, adsorption, films on solids.
Study of tinplate structure using imaging secondary ion spectrometry
Authors: Ramamurthy S. , Walzak T. L. , Lu S. F. , Lipson T. C. , McIntyre N. S. 
Published: May 2005

AbstractTinplate surfaces have been analysed on a microscopic scale for differences in composition which are related to their effectiveness in providing cathodic protection of the underlying steel. Secondary ion mass spectrometric images of a number of elemental and molecular ions have been collected and collated in stacks that represent the three‐dimensional distribution of the ions in the tinplate. An iron–tin alloy structure at the interface of the tin and steel appears to be detectable by the measurement of the 176FeSn− molecular ion image. The localized corrosion behaviour of the tinplates studied has been correlated to the microscopic distribution of iron near the outer surface of the tinplate; the presence of such an iron‐rich phase could increase the dissolution rate of surrounding tin and thus reduce the effectiveness of the cathodic protection provided to the steel substrate. The steel substrate was shown to have a low but detectable concentration of oxygen from its interface with tin down to a depth of 1–2 μm.
XPS and SSIMS analysis of polymers: The effect of remote nitrogen plasma treatment on polyethylene, poly(ethylene vinyl alcohol) and poly(ethylene terephthalate)
Authors: Foerch R. , Johnson D. 
Published: May 2005

AbstractA study has been undertaken in which both x‐ray photoelectron spectroscopy (XPS) and Fast atom bombardment static secondary ion mass spectrometry (FAB‐SSIMS) have been used to study the effects of remote nitrogen plasma treatment on polymers such as linear low‐density polyethylene (LLDPE), poly(ethylene vinyl alcohol) (EVOH) and poly(ethylene terephthalate) (PET). For comparison, remote oxygen plasma treatment was also performed on LLDPE. A very rapid uptake of nitrogen was observed for all polymers. Negative FAB‐SSIMS indicated CN−, CNO− and C2N fragments on each of the nitrogen plasma‐treated polmers. Positive FAB‐SSIMS spectra of plasma‐treated LLDPE showed relatively high intensity, high mass fragments, thought to originate from additives. These were not observed for the other two polymers. Significant amounts of aromatic‐type fragments were observed in the positive FAB‐SSIMS spectra of all treated polymers. Surface stability studies have shown that for both nitrogen and oxygen plasma‐treaed LLDPE there is a substantial decrease in the surface functionality on exposure to air. This effect was much less prevalent for EVOH and PET.
Depth profile analysis of aluminium metallization in microelectronics: Optimization of depth resolution
Authors: Pamler W. , Wangemann K. 
Published: May 2005

AbstractDepth profiling of aluminium metallization in microelectronics devices by Auger or SIMS analysis is impeded by the severe sputter‐induced roughening which causes a serious loss in depth resolution. This paper discusses strategies to avoid this deteriorating effect: optimization of the bombardment angle, sample rotation during sputtering and the use of heavy or reactive ions. The best depth resolutions were achieved by sputtering with normal incidence 15 keV O2+ ions. In this case, an interface width of 12 nm was measured for a film of 1 μm thickness. This is an improvement by more than a factor of 10 compared to the extremely poor depth resolution of 160 nm resulting from routine analysis parameters (Ar+ ions incident at 55°).
Structural and electronic studies of clean and oxidized thin Fe films on polycrystalline copper
Authors: Di Nardo S. , Passacantando M. , Picozzi P. , Santucci S. , Lozzi L. , De Crescenzi M. , den Daas H. 
Published: May 2005

AbstractThe local structure of very thin films of iron, deposited in an ultrahigh vacuum (UHV) onto polycrystalline copper and submitted to oxidation and thermal treatments, has been studied by surface electron energy‐loss fine structure (SEELFS) spectroscopy in reflection mode beyond the L2,3‐edges of iron and the K‐edge of oxygen. These results have been correlated to x‐ray photoemission (XPS) measurements performed on the same samples. Our results can be summarized as follows: lowering of the lattice parameter of the iron deposit, supporting the hypothesis of a cluster growth; selectivity toward the oxidation process of the iron deposits with respect to the copper substrate; restoring the metallic behaviour of the iron deposit after thermal treatment.
Optical Characterization of Silicon Oxynitride Thin Films by Variable Angle Spectroscopic Ellipsometry
Authors: Xiong Yi‐Ming , Snyder Paul G. , Woollam John A. , Al‐Jumaily G. A. , Gagliardi F. J. , Mizerka L. J. 
Published: May 2005

AbstractSilicon oxynitride (SiOx Ny) thin films were deposited on silicon substrates by ion‐assisted deposition. Variable angle spectroscopic ellipsometry (VASE) was used to optically characterize the deposited film properties, such as layer thickness and composition, film surface and interface qualities, as well as the retractive index spectrum in the wavelength range 320–820 nm. The measured VASE spectra were analyzed by assuming SiOx Ny to be a physical mixture of two distinct phases, silicon dioxide and silicon nitride, using the Bruggeman effective medium approximation. Remarkably good agreements between the measured spectra and model calculations were obtained over the entire spectral range for all the samples studied. Layer thicknesses of SiOx Ny films determined by VASE were consistent with their corresponding nominal values. The ellipsometrically deduced refractive index spectrum was observed to be strongly dependent on the film composition. In addition, the film refractive index at each applied wavelength was found to be a linear function of its constituent relative volume fraction. The results from VASE analysis also indicated that all the sample films investigated exhibited smooth surfaces, sharp interfaces between the film and substrate and high packing density.
Characterization of epitaxial SiGe thin films on Si: Analytical considerations
Authors: Evans K. L. , Anderson T. A. , Liaw M. , Gregory R. , Munukutla L. V. , Graham R. J. , McCartney M. R. 
Published: May 2005

AbstractEpitaxial silicon—germanium (SiGe) thin films are being developed for a number of interesting applications. Potential uses include applications as fabrication layers for heterojunction bipolar transistor devices and a number of other novel electronic devices. For device applications, SiGe structures offer the potential for increased speed, bandgap engineering, rapid oxide growth and low processing temperatures.For electronic device applications, successful fabrication of SiGe films with the desired properties requires a thorough understanding of deposition, oxidation, interdiffusion and interface behavior. This paper details the analytical methods employed to characterize SiGe thin films deposited in various molecular beam epitaxy (MBE) and chemical vapor deposition (CVD) reactor systems. Rutherford backscattering spectrometry (RBS), secondary ion mass spectrometry (SIMS), Auger electron spectroscopy (AES) and transmission electron microscopy (TEM) are used to study both the as‐deposited and oxidized films.Determination of Ge content and distribution, measurement of dopant concentrations within the SiGe, build‐up of Ge at oxide interfaces, build‐up of oxygen at interlayer interfaces and film thickness measurements will be illustrated. Methods for the cross‐correlation and calibration of the various instrumental techniques and use of the characterization data to optimize processing conditions will also be discussed.
Quantification of surface hydroxides using chemical labeling and XPS
Authors: Dang Tuan A. , Gnanasekaran R. , Deppe Denise D. 
Published: May 2005

AbstractXPS when used in conjunction with silylation can determine surface hydroxide. The penetration depth was studied using DRIFT and various silylation conditions. Application of this technique to many different inorganic matrices, including Si3N4, glass, silica thin film, zinc silicate lamp phosphor and Al2O3, is illustrated.
Surface oxidation of silicon carbide platelets as studied by x‐ray photoelectron spectroscopy and bremsstrahlung‐excited Auger electron spectroscopy
Authors: Wang Pu Sen , Malghan Subhas G. , Hsu Stephen M. , Wittberg T. N. 
Published: May 2005

AbstractX‐ray photoelectron spectroscopy (XPS) and Bremsstrahlung‐excited Auger electron spectroscopy (XAES) were used to study the surface composition and oxidation of silicon carbide platelets which had been heated in air at 500–800° C. The surface oxide thickness for each heating time and temperature was calculated independently from the SiO2/SiC intensity ratios in both the Si 2p XPS and the Si KLL XAES spectra. The results from these two methods agreed to within our calculated experimental error. Both methods revealed that the oxidation rate was non‐linear and non‐parabolic in this temperature range. Boron oxide was observed on the SiC platelets after heat treatment. Boron is used by the manufacturer as a catalyst and remains as an impurity in the SiC platelets.
AES determination of compositional variation in LPCVD tungsten silicide films in confined spaces
Authors: Rogers B. R. 
Published: May 2005

AbstractCompositional variation in chemical vapor deposited tungsten silicide films in confined spaces has been studied using scanning Auger electron spectroscopy. ‘Infinitely’ long silicon trenches with aspect ratios ranging between 1.5 and 5 were used to define the confined space. Composition changes down the sidewall of a partially filled trench were determined by cleaving the sample along the length of a trench and analyzing specific points down the sidewall. The samples were lightly sputtered before analyzing to remove the native oxide and reach a uniform composition of the silicide. The sample was carefully positioned during sputtering to minimize any redeposition of material onto the analysis area due to sputtering of adjacent surfaces. Using this method the silicon content of the silicide was shown to increase as a function of distance from the surface. This spatial variation in film composition qualitatively agrees with the predictions of a computer simulation of the deposition process.
A tandem SIMS study of poly(vinyl methyl ether)
Authors: Leggett G. J. , Chilkoti A. , Ratner B. D. , Vickerman J. C. 
Published: May 2005

AbstractResults are presented for a tandem‐SIMS investigation of the fragmentation patterns of secondary ions sputtered from the surface of poly(vinyl methyl ether) (PVME). A complete fragmentation sequence is deduced which is capable of explaining the formation of most of the major ions observed in the SIMS spectrum in terms of fragmentation steps proceeding from the largest secondary ion observed. The fragmentation steps involved in the formation of these ions are discussed and the secondary ion structures are identified.
Towards a universal curve for electron attenuation: Elastic scattering data for 45 elements
Authors: Werner W. S. M. 
Published: May 2005

AbstractThe attenuation parameter (AP), which quantitatively describes the influence of elastic electron scattering on the electron spectroscopies, has been calculated for 45 elements (Be, C, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, As, Se, Sr, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, Cd, In, Sn, Sb, Te, Ba, La, Hf, Ta, W, Re, Os, Ir, Pt, Au, Pb) and for energies of 250, 500, 1000 and 1500 eV. The calculations were performed with a Monte Carlo algorithm in which elastic scattering is modelled by use of the partial wave expansion method. The results show a linear relationship between the AP and the inelastic mean free path (IMFP), and a linear least‐squares fit of the data provides a simple formula to calculate the AP for a given material and energy. The depth distribution function (DDF), which in the most general sense discribes the attenuation properties of signal electrons, can be calculated analytically using this AP. The possibility of using the calculated AP values in combination with this DDF to extract IMFP data from an overlayer experiment has also been explored. Evidence is found, and discussed, that the presentedalgorithm can be used to convert IMFPs to attenuation lengths (AL).
Investigation of sputter‐induced surface composition modification during in‐depth profiling of implanted materials by sims, XPS and AES
Authors: Darque‐Ceretti E. , Aucouturier M. , Boutry‐Forveille A. 
Published: May 2005

AbstractDepth profile analysis by SIMS (secondary ion mass spectrometry), XPS (x‐ray photoelectron spectroscopy) and AES (Auger electron spectroscopy) have been performed on copper‐implanted monocrystalline silicon and zinc‐implamented polycrystalline copper under various ion sputtering conditions. A comparison of the different composition profiles shows an important influence of the ion sputtering parameters and of the analysis method on the apparent distribution of the implanted impurities.The results can be interpreted in terms of variations of the surface or subsurface composition during sputtering, taking into account preferential sputtering and/or sputter‐induced segregation phenomena. An unexpected improvement of ionization yields owing to contaminating oxygen may also induce artefactal modifications during the transitory sputtering period. The analysis of sputtered matter (SIMS) under O2 sputtering appears to be the most reliable analysis method, although the results, even in that case, can be altered by segregation phenomena.A comparison of the sputtered matter and the surface analysis method leads to the experimental determination of differential sputtering ratios for both systems.