bluuebunny/crossref_metadata_2025_split huggingface dataset:
Intergranular fracture surface analysis of molybdenum
Authors: Morito Fumio 
Published: December 2004

AbstractBend properties of plasma beam and/or electron beam melted molybdenum and several dilute alloys containing C, B, T, V and Re were investigated. Fracture surfaces and microstructure were examined in detail by SEM and AES. Considerable intergranular fracture occurred in almost all of the samples as the test temperature decreased. But proper alloy addition, such as B and Ti, and hot‐rolling induced a change in the fracture mode to a transgranular mode. Segregation of nitrogen and/or oxygen to grain boundaries was often recognized in plasma beam or electron beam melted ingots and decreased the strength of grain boundaries. Small precipitates due to comparatively low alloy addition such as C, B, Ti and Re, were effective to enhance the grain boundary cohesion.
Silver halide infrared fibre‐optic evanescent wave spectroscopy for in situ monitoring of the chemical processes in adhesive curing
Authors: Margalit E. , Katzir A. , Dodiuk H. , Kosower E. M. 
Published: December 2004

AbstractA silver halide infrared fibre‐optic evanescent wave spectroscopic technique for in situ monitoring of chemical processes and surface analysis is described. Attenuated total internal reflection (ATR) measurements with a Fourier transform infrared (FTIR) spectrometer allow spectra to be acquired at successive stages of chemical processes occurring within the surface layer. Samples are spread onto a fibre contained in a Teflon‐lined cell, and may be maintained under appropriate conditions of temperature and atmosphere. Monitoring of adhesive curing and coupling agent polymerization is accomplished easily and changes in spectroscopic features may be recognized in films as thin as a monolayer. The advantages and limitations of this surface analysis technique are discussed.
Surface enrichment in CuOx/ZnO samples at low Cu contents
Authors: Reyes Patricio , Sermon Paul A. 
Published: December 2004

AbstractA recent report (G. Moretti et al., Surf. Interface Anal. 14, 325 (1989)) in this journal has used XPS to show unequivocally that surface enrichment of calcined CuOx/ZnO co‐precipitates does not occur substantially; here, similar evidence for samples of low Cu content suggests that surface enrichment by copper does occur. This is an important finding for model precursors of methanol synthesis catalysts.
XPS study of transition metal/alumina model catalysts: Equilibrium and energy referencing
Authors: Légaré P. , Fritsch A. 
Published: December 2004

AbstractWe have used XPS to examine some model catalysts obtained by vapour deposition of Ni, Pd and Pt on an α‐alumina single‐crystal. It is shown that the binding energies of the substrate core levels with respect to the metal Fermi level depend on the metal work function. This is due to the fact that the common reference level between the metal and the insulating support is the vacuum level, although the Fermi level reference only gives a chemical aspect to the binding energy shifts on the metal. The consequences for XPS analysis of supported catalysts or any metal/insulator system are discussed.
Surface structure of MgF2‐supported vanadium oxide monolayer catalysts
Authors: Haber J. , Stoch J. , Wojciechowska M. 
Published: December 2004

AbstractVanadium oxides supported on MgF2 with rutile structure, obtained by impregnation and precipitation–deposition, were investigated. XPS, ESR, IR and XRD studies revealed that the surface of MgF2 is partially covered by non‐acidic OH groups, which persist after loading with vanadium oxides. In impregnated samples, the surface fraction of vanadium is linearly dependent on loading. In precipitated–deposited samples, the surface fraction of vanadium remains constant because of the increase of surface area due to peptization of MgF2 aggregates. At a low concentration of vanadate solution, (VO)F5‐type surface complexes are formed. At higher concentrations, isolated VO4 tetrahedra appear at the surface, which undergo polymerization to form chains of tetrahedra or trigonal bipyramids. These may condense further into islands of the monolayer of polyvanadate species, with the σπ‐bonded terminal oxygen sticking out perpendicular to the surface.
Restoration of the depth–concentration profile from the angle‐resolved relative intensities of x‐ray photoelectron spectra
Authors: Jisl Rudolf 
Published: December 2004

AbstractA numerical method for the restoration of the depth–concentration profile from the angular distribution of XPS intensities is described. The proposed method is based on the regularization theory. A simpler formulation of the basic relationships than has been given in previous works2–8 enables the inclusion of more general a priori information. A new approach is also given for the choice of the most suitable profile for the experimental data, which enables restoration of profiles with up to two extremes. Calculations performed for all typical profiles show good agreement with the simulated data. The applicability of the method is demonstrated on the depth–concentration profile restoration of the SiO2/Si interface in the silicon surface barrier detector.
An IETS study of some selected tripodal adsorbates on plasma‐grown aluminium and magnesium oxides
Authors: Brown N. M. D. , Taggart G. M. 
Published: December 2004

AbstractA study of the inelastic electron tunnelling (IET) spectra of tris(hydroxymethyl)ethane, tris(2‐hydroxyethyl)amine, and tris(hydroxymethyl)phosphine oxide, show that all three hydroxy groups for each of these adsorbed species are surface bound. From closer inspection of the spectra for tris(hydroxymethyl)ethane and tris(hydroxymethyl) phosphine oxide, a tripodal geometry at the surface involving interactions between the three functional groups and one cation is proposed. Whereas for tris(2‐hydroxyethyl)amine and tris(2‐aminoethyl)amine, owing to their additional structural flexibility, more than one surface adsorption site may be involved per adsorbed molecule. In the case of tris(2‐aminoethyl)amine, the IET spectra indicate that both amino group protonation and Lewis acid‐Lewis base interactions are involved in the binding of this species to both oxide surfaces.
Preferential sputtering of GaAs
Authors: Malherbe J. B. , Barnard W. O. , Strydom I. Le R. , Louw C. W. 
Published: December 2004

AbstractLow‐energy (0.65–3 keV) Ar+ ions were used to sputter (100) and (110) GaAs. Preferential sputtering effects were investigated by means of Auger electron spectroscopy. The results show that the equilibrium sputtered surface composition on both surfaces is depleted in As. No sample orientation effects were observed. However, the equilibrium compositions of the sputtered surfaces become increasingly Ga‐enriched by increasing the energy of the bombarding ions. The sputtered surface composition is independent of the angle of incidence of the bombarding Ar+ ions. For the different experimental conditions, the mean final surface compositions varied from GaAs0.89 to GaAs0.69. These values are in broad agreement with other reported AES studies. This agreement is probably due to the fact that the sputtered surface composition is independent of the angle of incidence of the ions on the GaAs sample.
Tin, Tic and Ti(C, N) film characterization and its relationship to tribological behaviour
Authors: Bertoncello R. , Casagrande A. , Casarin M. , Glisenti A. , Lanzoni E. , Mirenghi L. , Tondello E. 
Published: December 2004

AbstractScanning electron microscopy observations, energy dispersive spectroscopy, x‐ray diffraction and x‐ray photoelectron spectroscopy analyses have been employed to study the composition and the microstructure of titanium carbonitride coatings deposited by a reactive ion‐plating industrial system. Both TiN and Ti(C, N) coatings show a very fine and dense microstructure and consist of a NaCl‐type single phase with a marked preferred orientation. X‐ray photoelectron spectroscopy analysis of the characteristic Ti, C and N lines establishes the extent of Ti(C, N) compound formation and the dependence of composition on the reactive gas flow ratio. Depth profiles obtained by XPS analyses after cycles of Ar+ sputtering indicate chemical uniformity of the films. Microhardness measurements taken on coated HSS specimens show that Ti(C, N) are significantly harder than TiN and TiC films deposited under the same conditions. Ti(C, N) coatings have a lower coefficient of friction and a higher wear resistance than TiN coatings, irrespective of the mating material.
Comparison of background removal methods for XPS
Authors: Repoux M. 
Published: December 2004

AbstractPhotoelectron peak areas are measured using various background removal methods. Linear, horizontal, Shirley's and Tougaard's backgrounds have been tested on many spectra for different pass energies in the spectrometer. These four values, obtained for each photoelectron line, are compared together and it is shown that the first three methods give proportional results. These values are then compared to theoretical intensitities for five elements (Au, Ag, Cu, Ni, Cr) and one oxide (Al2O3). These theoretical calculations are based on the knowledge of the spectrometer transmission, photoionization cross‐sections and inelastic mean free path, the product of which is commonly called the relative sensitivity factor. The best agreement is obtained when Tougaard's background is removed.
Auger analysis of etch residues in submicrometer via holes using focused ion beam sample preparation
Authors: Hoener Carolyn F. , Shaver Brian , Nguyen Thien T. 
Published: December 2004

AbstractThe composition and thickness of etch residues on the base of submicrometer via holes cannot be surmized from data on larger features. Auger sputter depth profiles were used to compare etch residues in 0.55 μm via holes produced by different etch processes and remaining after different cleans. These residues varied significantly in composition and thickness with the processing history of the sample and from those on larger features. A focused ion beam (FIB) sample preparation was developed to expose the bases of via holes and to help reduce sample charging.
X‐ray photoemission spectroscopy study of band bending at the interface of metal with poly(p‐phenylene vinylene)
Authors: Ettedgui E. , Razafitrimo H. , Park K. T. , Gao Y. , Hsieh B. R. 
Published: December 2004

AbstractWe report on our recent x‐ray photoemission spectroscopy investigations of the interface formation of metals with poly(p‐phenylene vinylene) (PPV) prepared under various conditions. We have found that during deposition the metal reacts with residual hydroxyl groups in the polymer. In addition, we have found that Schottky barrier formation and the associated band bending depend strongly on surface preparation. In the case of Al deposition, samples converted in situ, containing 5% surface oxygen, show band bending that depends on the thickness of the metal overlayer, with effects arising after as little as 1 Å of metal. On the other hand, a sample converted ex situ, with 10% surface oxygen, is insensitive to aluminium deposition. We feel that surface impurities and adsorbed species may delay Schottky barrier formation by acting as a buffer layer that prevents the PPV substrate from interacting with the growing layer of Al. By contrast, the Ca/PPV surface exhibits delayed band bending, with strong interactions between surface oxygen and Ca. Our results indicate that band bending at the metal/PPV interface is governed by the metallicity of the metal overlayer, which itself is influenced by the interface reaction of the deposited metal with the PPV substrate or the surface residual impurities. Finally, the degree of band bending observed did not correlate directly with the differences in work functions between the metals and PPV.
Studying long‐range spin ordering on surfaces by metastable He 23S scattering
Authors: Marynowski M. , Franzen W. , El‐Batanouny M. , Swan A. , Martini K. M. 
Published: December 2004

AbstractWe have developed a technique for using diffractive scattering of metastable 23S He (He*) to determine the long‐range electron spin ordering on the surfaces of magnetic insulators. The technique is based on the fact that the probability of He* surviving a scattering event can be significantly enhanced when an appropriately located electron energy gap and localized spins are present on the surface. A periodic arrangement of the orientation of the local moments on the surface then leads to a periodic modulation of the beam attenuation that is reflected in the corresponding diffraction pattern. In these initial studies, we measured the electron spin‐ordering on a NiO (100) surface, and found a structure of periodicity (6 × 1), which is quite different from the bulk antiferromagnetic arrangement. We modeled the scattering process using a modified version of the eikonal approximation, in which a dissipative hard corrugated wall simulates the spatially modulated attenuation of the He beam. Calculations performed on this model were in good qualitative agreement with our experimental data.
Application of the infinite velocity method for quantifying negative secondary ion emissions to multi‐layered samples
Authors: van der Heide P. A. W. , Ramamuthy S. , McIntyre N. S. 
Published: December 2004

AbstractThis report illustrates, in a stepwise fashion, the application of a new method for quantifying SIMS results (termed the infinite velocity method) to the depth profile analysis of multilayered samples. The two samples analysed comprised a silicon substrate implanted with cobalt and a silicon substrate bearing an oxide layer implanted with boron. Concentrations were extracted by: sampling the secondary ion emissions over several kinetic energies during the depth profile; correcting the resulting intensities for instrument transmission and sputter yield effects, so that these may be poltted against the inverse of the velocity; and referencing the point at which the resulting curves intersect with the intensity axis (intensity at infinite velocity) to an element whose concentration is known, or to the sum of all major element intercept data. Characteristic velocity data obtained from each cycle of the depth profiles were also used to illustrate a new method for defining the position of the interface. To illustrate the validity of these results, peak concentrations were compared with those calculated via the integration method as well as Auger depth profile analysis.
Static SIMS: Surface charge stabilization of insulators for highly repeatable spectra when using a quadrupole mass spectrometer
Authors: Gilmore I. S. , Seah M. P. 
Published: December 2004

AbstractSurface charge stabilization is important to achieve stable static SIMS spectra from insulators. For static SIMS using a quadrupole mass spectrometer, the problem is exacerbated by the narrow spread of ion energies passed by the quadrupole system. Here, for a positive ion beam we study three methods of electron beam surface charge neutralization and compare their effectiveness for large‐area static SIMS analysis. These methods are: a traditional low‐energy flood source aimed at the sample; a 500 eV electron beam aimed at the sample; and a low‐energy source of scattered electrons placed between the sample and the quadrupole‐based static SIMS entrance ion optics. The latter method is shown to be efficient, easy to use and reliable. Variations in the surface potential are considerably reduced but small variations still show an effect leading to variable intensities in different peaks. This variation is reduced a further order of magnitude so that, in the static mode, final scatters for poly(tetrafluoroethene) have standard deviations below 2%. This final reduction is achieved by the application of a triangular waveform potential of 32 V peak‐to‐peak amplitude at 6.5 kHz frequency, to the sample holder and the sample environment. The mass spectra are then equivalent to the results for a mass spectrometer with a 32 eV wide energy acceptance window.
Study of the reduction behavior of W/TiO2 catalysts by XPS using curve fitting, deconvolution and factor analysis
Authors: Fiedor Joseph N. , Proctor Andrew , Houalla Marwan , Hercules David M. 
Published: December 2004

AbstractX‐ray photoelectron spectroscopy (XPS, ESCA) was used to determine the tungsten oxidation states in a 5 wt.% WO3/TiO2 catalyst reduced in hydrogen in the temperature range 400–700°C. Because, in the region of interest, W 4f overlaps with the Ti 3p energy level, a multiple analysis procedure including deconvolution, non‐linear leastsquares curve fitting and factor analysis was used to analyze the data. Deconvolution was better able to resolve the peaks in the W 4f region and thus elucidate the positions of the tungsten components for each reduction temperature. It was shown that there is a maximum of three W 4f doublets. The W 4f7/2 peaks of these components were located at 35.5, 33.3 and 31.1 eV and they were assigned to W+6, W+4 and Wo, respectively. Factor analysis verified the presence of three spectral tungsten components. X‐ray diffraction verified the presence of Wo on reduction at 675°C. Non‐linear least‐squares curve fitting, using the positions from deconvolution, was able to determine the distribution of tungsten oxidation states as a function of reduction temperature: W+6 steadily decreased with increasing reduction temperature, W+4 initially appears at 408°C and goes through a maximum around 580°C; Wo was first detected following reduction at 550°C and was the only species present for reduction temperatures higher than 665°C. From the distribution, it is proposed that, unlike the molybdenum systems, tungsten undergoes a more simplified reduction process in which only one intermediate oxidation state (presumably W+4) is detected.
Analysis of polymers by auger electron spectroscopy with a cold stage
Authors: Sekine Tetsu , Ikeo Nobuyuki , Nagasawa Yuji , Kikuma Jun 
Published: December 2004

AbstractIn order to analyse polymers by AES, the electron discharge from the sample surface and the reduction of electron irradiation damage must be taken into account. A cooling device for a scanning Auger microprobe was developed that allows five axis movements, especially allowing a large dynamic range of tilt movement. The electron beam irradiation effects were examined for CI LVV and C KLL transitions at temperatures of −185, −150, −100 and 24°C using slices of polyvinyl chloride specimen of ∼200 nm in thickness. At −185°C, the allowed dosage for the analysis without causing any remarkable damage is up to 0.3 C cm−2. The electron dosage effects are not so strong. The logarithmic concentration ratio log(Ccl/Cc) falls down linearly against the logarithmic electron dosage log(electron dose) with a slope of about −0.22. At higher temperatures the damage take place immediately after electron irradiation, and it cannot be avoided. This immediate damage is not due to the dosage effects but to the temperature elevation.
Atomic force microscopy investigations on polymer latex films
Authors: Anczykowski B. , Chi L. F. , Fuchs H. 
Published: December 2004

AbstractAtomic force microscopy (AFM) is applied on two different types of thin latex films. Polystyrene dispersion particles are prepared by various methods to form well‐ordered monolayers and multilayers. Atomic force microscopy serves as a tool to study the surface structures of such films and to find the optimal preparation conditions. The micromorphology of the second system, an adhesive tape, was imaged successfully by AFM running in dynamic mode. Besides the morphological studies, the interaction between the sticky surface and the AFM tip is measured by the damping of the cantilever oscillation versus tip–sample distance.
Target factor and neural network analyses applied to titanium nitride composition recognition by AES
Authors: Card Jill , Testoni Anne L. , Le Tarte Laurie A. 
Published: December 2004

AbstractThis paper details the development of two pattern recognition approaches—modified target factor analysis (TFA) and artificial neural network analysis—applied to Auger electron spectra for precise discrimination of thin‐film TiNx compound composition. Use of Auger electron spectroscopy for the analysis of titanium nitride films offers advantages over other spectroscopic methods in its ability to analyze either blanket‐deposited films or submicron features on patterned wafers and its speed of sample preparation and spectral processing. However, severe overlap of the characteristic Ti LMM and N KLL transitions between 380 and 390 eV prohibit direct stoichiometry measurement. Modified TFA and multilayer perceptron (MLP) neural network approaches are applied to the task of discriminating TiNx stoichiometries to within 2% of a nominal 1:1 composition. The modified TFA procedure succeeded in accurate prediction of AES spectra TiNx stoichiometries in five of six sample groupings. The MLP neural network approach accurately predicted stoichiometries for all samples with reduced sample variance over standard analytical methods. This work combined AES and neural network technologies to improve significantly the precision of the stoichiometric composition recognition capability for TiNx compounds.
Quantitative investigation of the O2+‐induced topography of GaAs and other III–V semiconductors: An STM study of the ripple formation and suppression of the secondary ion yield change by sample rotation
Authors: Karen A. , Nakagawa Y. , Hatada M. , Okuno K. , Soeda F. , Ishitani A. 
Published: December 2004

AbstractRoughening procedures including the early stage of the O2+‐induced ripple formation of GaAs were studied quantitatively by scanning tunnelling microscopy (STM). Detailed examinations of the beginning of topography development using fast Fourier transform of the STM images revealed that the ripple formation was not caused by any accidental defects, particles or original irregularity on the substrate, but solely by the conditions of the ion beam. A systematic investigation of the rippled GaAs surface produced under various O2+ bombardment conditions was conducted. The ripple wavelength and the transition depth were almost exactly proportional to EPcos θ, where EP and θ are the energy of the ion beam and the incident angle, respectively. For GaAs, the secondary ion yield transition occurs when the slope of ripples facing the incident O2+ beam reaches a saturation angle of 20–30° from the macroscopic surface plane. Topography change on other III–V semiconductors was also examined for comparison. There was no ripple generation observed for GaP; InP gave a ripple‐like structure without secondary ion yield change. A relatively rough surface resulted on GaSb and InAs at a much shallower depth than for GaAs. Rippling and ion yield changes during depth profiling have been suppressed successfully by sample rotation even in a magnetic sector‐based instrument.
Update: lead stabilizers
Authors: Kincius Edward J. 
Published: December 2004

AbstractAs it stands today, the outlook for the lead stabilizer industry couldn't be better. There are several reasons why we feel this is so. One reason is that governmental regulations have been known to the industry for several years. Because of this, suppliers have been very successful in helping consumers meet existing regulations through education, training, and improved handling technology. Also, we are aware of no new or pending legislation that would place additional restrictions on lead.Other reasons for optimism include increased cost advantages when compared to other types of stabilizers available and the potential from new application areas.My intent is to review what the industry has done to promote customer compliance regarding governmental regulations and to elaborate on reasons for our optimistic outlook concerning the future of the lead stabilizer industry.