bluuebunny/crossref_metadata_2025_split huggingface dataset:
SIMS–RBS depth profiling of silver‐diffused glass systems
Authors: Quaranta A. , Gonella F. , Caccavale F. C. , Brusatin G. 
Published: May 2005

AbstractBoth SIMS and RBS techniques are used to obtain smooth accurate concentration profiles of silver diffused into soda‐lime glass systems. By a computer simulation, a combination of the two techniques enables more detailed information to be obtained on the silver distribution at a depth of up to several micrometres, and the concentration profiles can be used effectively for testing the reliability of some optical behaviour characterizations of glass waveguiding structures.
Time‐of‐flight secondary ion mass spectrometry of polybutadienes
Authors: Hittle Lucinda R. , Hercules David M. 
Published: May 2005

AbstractHigh resolution time‐of‐flight secondary ion mass spectrometry was used to study a series of polybutadienes with molecular weights between 400 and 170 000 Da. The number‐averaged and weight‐averaged molecular weights of polybutadienes with molecular weights of <5000 Da were determined and showed reasonable agreement with values obtained by conventional methods. Samples with molecular weights of >5000 Da showed primarily fragments in the mass range 500–4000 Da, resulting from main chain cleavage of CC single bonds. A fragmentation model based on simple statistical chain cleavage was used to explain the fragmentation patterns observed in the spectra. These fragmentation patterns contained Rn, +Δ, +2Δ and −Δ species, where Rn represents an integral number (n) of repeat units and Δ is a methylene group. The relative intensities of these clusters as a function of sample molecular weight and cluster size were studied, and were the same regardless of polymer size. The fine structure of the fragment clusters was also examined, and the mechanisms responsible for their formation are discussed.
Degradation of cleaved LnSb(Ln = La, Ce) by reaction in ultrahigh vacuum and air
Authors: Oku Masaoki , Suzuki Takashi 
Published: May 2005

AbstractThe degradation of LaSb and CeSb in ultra high vacuum and air has been studied by XPS. The exposure of the surfaces cleaved in situ to the XPS spectrometer vacuum, produced with a cryo pump, slowly changes them into lanthanide oxides and elemental antimony. The cleavage of LaSb in air also induced oxidation of the elemental antimony. The binding energies of Sb3/2,5/2 of elemental antimony produced in the vacuum were the same as those of bulk metal Sb. However, a chemical shift of the level of the elemental Sb in decomposition layers on the samples cleaved in air was positive for LaSb and negative for CeSb.
Chemical environment of Ba2+ in a series of chalconide and halide salts
Authors: Berrie C. L. , Langell M. A. 
Published: May 2005

AbstractBarium Auger parameters correlate linearly with fractional ionic character, defined by simple electronegativity concepts. More fundamentally, the variation in Auger parameter is quantitatively associated with ligand polarization energy Ep, resulting from the interaction of the polarizable ligands with the barium core hole coulombic field. This paper demonstrates the Ba2+ Auger parameter correlations, and is complementary to work published previously in this journal (C. L. Berrie and M. A. Langell, Surf. Interface Anal. 17, 635 (1991)).
Preparation and characterization of organic superlattice thin films grown on hydrogenated silicon single‐crystal substrates
Authors: Ishitani A. , Nonaka T. 
Published: May 2005

AbstractWe have succeeded in preparing very thin (nanometre order) alternating layers that can be called ‘organic superlattices’ by using a special combination of materials, substrates and deposition conditions with good verification by various characterization techniques.Specially surface‐treated single‐crystal silicon substrates with hydrogen‐terminated dangling bonds on the surface were used to induce van der Waals heteroepitaxial growth. Choice of materials with the appropriate molecular shapes and aggregation force is also important for preparing flat molecular films. Tetraphenylporphyrins (H2TPP and ZnTPP) and phthalocyanines were used for this purpose. A molecular beam epitaxy chamber with specially designed cells was used with the cooled substrates.Direct proof of the alternating composition was given by transmission electron microscopy observation, avoiding decomposition by the electron beam, and also by SIMS depth profiling under special conditions to ensure good depth resolution. X‐ray diffraction in the small‐angle region gives the periodicity of the alternating layers, as well as their crystal quality. Atomic force microscopy confirms the atomic flatness and also gives the molecular orientation in the films. Fourier transform infrared spectroscopy examines the chemical stability of the compounds during deposition and also gives the axial orientation of the molecules in the films.
Interaction of oxygen with ZrN at room temperature: An XPS study
Authors: Prieto P. , Galán L. , Sanz J. M. 
Published: May 2005

AbstractQuantitative XPS has been used to characterize the interaction of oxygen with ZrN at room temperature. The results indicate that ZrN remains unaffected for oxygen exposures <104 L at oxygen pressures <10−7 Torr. However, higher oxygen exposures at higher pressures cause the formation of an oxynitride (ZrN0.5O0.5) and ZrO2. At 108 L saturation is reached, with the formation of an oxidized layer that is 17 Å thick formed by 5 Å of ZrO2 and an interface layer (12 Å thick) of average composition ZrN0.5O0.5. Analysis of the core levels and valence band of the oxynitride demonstrates its ionic character as well as its insulating properties in comparison with metallic ZrN.
An in situ XPS study of the formation of nickel—polyethylene and nickel—polypropylene interfaces
Authors: Marcus P. , Meyer A. , Hinnen C. 
Published: May 2005

AbstractThe initial stages of formation of nickel–polyethylene and nickel–polypropylene interfaces have been investigated by X‐ray photoelectron spectroscopy (XPS). Nickel was sputter‐deposited on the polymer surfaces in the UHV chamber attached to the spectrometer, and the Ni 2p3/2 and C1s regions were analysed in situ as a function of deposition time, until the completion of a metallic overlayer of ∼30 Å. The examination of the measured XPS spectra shows that there is no additional signal in the C1s region which would be associated with the formation of a strong chemical bond with charge transfer, in contrast with previous findings for aluminium sputter‐deposited on the same polymers. Accordingly, the Ni 2p3/2 region does not show any additional signal, but it exhibits a marked shift in the binding energy for the small amounts of deposited nickel (0.7 eV for the shortest deposition time). This shift in binding energy decreases with increasing amount of deposited metal. This observation gives evidence of the presence of small clusters on the surface, which finally form a continuous metallic layer with a thickness of ∼8 Å.
Use of XAS and chemical probes to study the structural damage induced in oxide ceramics by bombardment with low‐energy ions
Authors: Caballero A. , Leinen D. , Espinós J. P. , Fernández A. , González‐Elipe A. R. 
Published: May 2005

AbstractA preliminary study by x‐ray absorption spectroscopy (XAS) of the structural modifications induced in mixed oxides by low‐energy (1–5 keV) Ar+ bombardment is presented in this paper. The analysis of the extended x‐ray adsorption fine structure (EXAFS) and x‐ray adsorption near‐edge structure (XANES) spectra recorded for bombarded Al2TiO5 and BaTiO3 has shown the randomization of the atomic network and the formation of TiO2 in the outermost layers of these materials. On the other hand, SO2 is proposed as a probe molecule to asess semiquantitatively the extent of structural damage in the surface layers of bombarded oxides. The incorporation of sulphur into this zone has been proved by depth profiling with XPS and Ar+ ions of 0.5 keV. In BaTiO3 the incorporation of sulphur increases with the energy of the primary ions. This fact suggests that the concentration of defects increases with the energy of the Ar+ beam and that the most disordered surface layers are more reactive towards SO2. A similar effect is not observed with TiO2 and Al2TiO5 because in these materials, where a considerable reduction of titanium to Tin+ (n < 4) species is produced by the preferential removal of oxygen, an overlay of elemental sulphur is formed by the reaction of SO2 with these species. This overlay prevents the diffusion of SO2 and therefore the incorporation of sulphur into the damaged layer of those samples.
XPS/AFM study of thermally evaporated aluminium/polycarbonate interface
Authors: Massoro Claudia , Le Quoc Toan , Pireaux J. J. 
Published: May 2005

AbstractThe interfacial interaction between polycarbonate and in situ thermally evaporated aluminium has been studied by x‐ray photoemission spectroscopy.Core‐level spectra indicate that aluminium reacts, in the initial reaction stage, with the carbonyl groups (CO). In a second step, the CO entities begin to be involved. These mechanisms lead to the formation of a AlOC complex, confirmed by the appearance of a new component at lower binding energy in the C 1s signal.After about 1.7 Å of Al deposition a new C 1s component is also observed at lower binding energy and is attributed to the interaction between Al and the phenyl ring, which leads to a strong perturbation of the π electron system of the phenyl ring and then to an AlC bond. Analysis of the shake‐up satellites of metallized polycarbonate confirmed these interactions.The morphology, as observed by atomic force microscopy measurements, of the Al on polycarbonate is also presented.
XPS study of passive films formed on an iron—aluminium intermetallic compound in acid solution
Authors: Frangini S. , Giorgi R. , Lascovich J. , Mignone A. 
Published: May 2005

AbstractSurface films grown on the intermetallic B2‐FeAl alloy after wet‐mechanical polishing and after a wide range of anodic polarization conditions in 1N H2SO4 have been analysed by x‐ray photoelectron spectroscopy. The results clearly indicate a remarkable enrichment of aluminium within all the films regardless of the growth conditions. Analysis of the metal–oxygen bonds has made it possible to distinguish several oxidized species. It has been found that most of the iron hydroxides are concentrated on the film surfaces, whereas aluminium hydroxides appear more homogeneously distributed over the depth of the oxide films. The thickness of the film shows an abrupt increase at 1 V, accompanied by a marked increment of Al hydroxide species.
Surface analysis of patterned and selectively metallized silicon surfaces with imaging and static SIMS
Authors: Van Der Wel H. , Van Der Sluis‐Van Der Voort E. , Willard N. P. 
Published: May 2005

AbstractThe use of imaging and static secondary ion mass spectrometry is demonstrated for the chemical characterization of the top monomolecular layers of chemically modified and patterned silicon wafers. Surfaces with areas of different chemical compositions and reactivities (e.g. hydrophobic/hydrophilic) were created by chemical modification with a light‐sensitive organosilane, followed by UV irradiation or by chemical modification with 3‐aminopropyltriethoxysilane, followed by local removal of the silane through oxidation with UV ozone. The latter surfaces were also selectively metallized on the aminosilylated areas as an example of the applications possible for these patterned surfaces.The chemical surface composition and structure of the organosilylated and selectively metallized silicon wafers are adequately characterized with static SIMS. The patterns created on the wafers are observed with good contrast in the SIMS images of the molecular ionic fragments and elemental ions characteristic for the particular surface compositions. The results can be used to improve the chemical modification reactions.
Application of factor analysis to the auger electron spectroscopy study of YBa2Cu3O7−x superconductors
Authors: Roose N. , Ye M. , Vereecken J. , Seibt E. W. 
Published: May 2005

AbstractIn this paper factor analysis applied on AES measurements is used in the study of the chemical composition of YBa2Cu3O7‐x superconductors.In the first part, YBa2Cu3O7‐x thin films deposited on MgO and SrTiO3 are investigated by AES depth profiling. Factor analysis makes it possible to identify secondary phases present at the surface and the interfaces. This method also offers the possibility of determining the real interface thickness, as the edges of pure film and pure substrate are more accurately defined.In the second part, the radiation induced effects of a 10 keV electron beam are investigated on YBa2Cu3O7‐x single crystals. Besides the stoichiometric changes the chemical changes in function of the radiation dose are studied. Factor analysis indicates clear peak changes throughout the irradiation process.
Interaction of copper(II) ions with pyrite and its influence on ethyl xanthate adsorption
Authors: Voigt S. , Szargan R. , Suoninen E. 
Published: May 2005

AbstractX‐ray photoelectron spectroscopy (XPS) has been used to investigate the interaction of copper(II)‐containing aerated aqueous solution (pH 4–10) with pyrite (FeS2) surfaces and its influence on subsequent ethyl xanthate adsorption from solution. Evidence is provided that Cu(II) ions can be adsorbed independent of pH, changing their oxidation state to Cu(I). This is attributed to a new Cu–S surface species, In addition, Cu(II) can be stabilized as a complex hydroxy species on pyrite at pH ≥ 6. Time‐dependent adsorption studies were carried out to elucidate the influence of pH on the copper adsorption rate, considering also the different copper oxidation states. A fast saturation of the sulphide surface with Cu(I) is observed at pH 5, whereas the Cu(I) uptake starts only slowly at pH 8 and pH 10. Prolonged conditioning in alkaline solution results in a precipitation of Cu(II) hydroxy species. Simultaneously, the amount of adsorbed Cu(I) increases until the same Cu(I) level is reached as in acidic media. After subsequent immersion in ethyl xanthate solution of pH 6–9, both Cu(I) and Cu(II) ions adsorbed on pyrite are found to form Cu(I) ethyl xanthate in accordance with previously published infrared spectroscopic and microflotation results.
Simultaneous background subtraction and depth profile determination from AES/XPS measurements
Authors: Werner Wolfgang S. M. , Tilinin Igor S. , Beilschmidt Herbert , Hayek Markus 
Published: May 2005

AbstractA general expression for the energy and angular distribution of Auger/photoelectrons emitted from a specimen with an arbitrary depth profile is presented. The central quantities in this expression are the so‐called partial escape distributions, which describe the probability that a signal electron generated in a certain depth interval escapes from the surface with a direction in a certain angular interval after experiencing a certain number of inelastic scattering processes. The partial escape distributions accounting for elastic scattering are calculated in the transport approximation. Comparison of analytical calculations with Monte Carlo data based on the more relastic Mott crosssection for elastic scattering yields excellent agreement. As an illustration of the general approach, the energy/angular spectrum of a sample with a model depth profile has been evaluated using analytical calculations and Monte Carlo data. The results obtained show that the proposed formalism properly accounts for elastic and inelastic processes and correctly predicts the shape of the energy distribution in the vicinity of the peak. It is, moreover, shown that the true intrinsic spectrum and depth profile may be reconstructed simultaneously from the measured energy/angular distribution of emitted electrons.
Determination of surface stoichiometry in polycrystalline alloys by a crystallographic electron attenuation model: Application to the Ce/Rh system
Authors: Andersen J. E. T. , Warren J. P. , Zhang X. , Lambert R. M. 
Published: May 2005

AbstractIn order to obtain quantitative surface compositional information, an earlier crystallographic electron attenuation model has been extended to treat polycrystalline alloys. Simple correction factors are obtained that yield large corrections to elemental Auger intensity ratios. The model has been applied to a binary surface alloy formed by heating cerium overlayers on a polycrystalline rhodium substrate. It is shown that an alloy film is formed whose thickness is proportional to the number of Ce layers initially deposited. The surface alloy is identified as Ce3Rh2, which corresponds to a known bulk phase.
Influence of the surface chemistry on the wettability of stainless steel
Authors: Mantel M. , Wightman J. P. 
Published: May 2005

AbstractDegreasing with solvents, chemical etching, polishing, oxygen and argon plasma treatment and heating and drying produce stainless‐steel surfaces with different amounts of organic contamination and ‘bonded water’. The hydroxide/oxide layer of the passive film formed on stainless‐steel foils is also affected by surface pretreatment. Electron spectroscopy for chemical analysis (ESCA) has been used to analyze the composition of the surface film formed after different cleaning procedures. Organic contamination on 304 stainless‐steel foils can be reduced by a factor of five using various cleaning treatments. Wettability or surface energy measurements have been performed on the treated surfaces and it was found that the surface energy of the metal decays with the inverse of the contamination layer thickness. As these cleaning treatments lead to different oxide layers, it is concluded that the nature of the oxide layer is not the main parameter that determines the surface free energy of metals.
Calculations of a CHA transmission function for quantitative analysis in the constant pass energy mode. I. Point sources for AES
Authors: Kato M. , Sekine T. 
Published: May 2005

AbstractThe analyser transmission function T of a concentric hemispherical analyser (CHA) with an input lens system has been studied, and the behaviour of T under suitable operation conditions for a point source has been determined by means of numerical calculations. One of the significant factors controlling T was found to be the aberrations of the input lens, which have a strong dependence on the retardation ration γ and the angular magnification Mα of the lens. The Mα also determines the entering angles of electrons to the CHA, and thus this should be kept sufficiently small as far as the aberrations in the CHA are concerned. The calculated results showed, however, that for each γ there exists an optimum Mα, which corresponds to a compromise point between the aberrations of the input lens and those of the CHA. If Mα is kept constant, T varies according to the increase or decrease in the lens aberrations as functions of γ. Lineshapes calculated for a monochromatic point source were also shown. These were found to be asymmetrical and have tailings on the low‐energy side due to the aberrations of the CHA.
Incorporation of elastic scattering into composition–depth profile reconstruction from angle‐resolved Auger/XPS data
Authors: Dwyer V. M. 
Published: May 2005

AbstractNeglecting elastic scattering in the inversion process for reconstructing composition–depth profiles from angle‐resolved Auger/XPS spectra leads to several effects that are likely to be misinterpreted. For example, there appears to be an erroneous diffusion of the substrate material to the surface in the case of a simple overlayer. In addition, the thickness of the overlayer is likely to be overestimated by typically ∼20% for Auger/XPS energies.
Inhomogeneous charge effect on a natural mineral studied by XPS
Authors: Rueda F. , Mendialdua J. , Rodríguez A. , Casanova R. , Barbaux Y. , Gengembre L. , Jalowiecki L. , Bouqueniaux D. 
Published: May 2005

AbstractWe report on XPS results that show an inhomogeneous charge effect, greater than 1.0 eV and far greater than the accuracy of the measurements (∼0.2 eV), exhibited by a natural mineral essentially composed of SiO2 and Fe2O3. This mineral has proved to be an efficient catalyst in a Fischer–Tropsch reaction. We have corrected this differential charge effect by using two internal references in order to interpret satisfactorily our XPS data.
Oxidation study of 3d transition metals (Cr, Fe, Co and Ni) and rare earth (Tb): Application to auger depth profiling of magneto‐optical disk
Authors: Abe Y. , Kato A. , Nakamura T. 
Published: May 2005

AbstractThrough the oxygen exposure experiments on 3d transition metals (Cr, Fe, Co and Ni) and rare earth (Tb), we studied the initial oxidation by means of Auger peak‐to‐peak height (APPH) method. Based on the results obtained, a simple technique using the ratio of APPH was applied to the Auger depth profile analysis of magneto‐optical disk (MOD). It was clearly indicated that the preferential oxidation of Tb occurred only at the lower interface between the TbFeCo and metal‐oxide layers, and this technique can be used to obtain the chemical information about the interface oxidation in Auger depth profiling.
Ion beam analyses of ceramics and glasses in nuclear energy
Authors: Matzke Hj. 
Published: May 2005

AbstractIon beam techniques (Rutherford backscattering (RBS) with and without the channeling effect technique, resonance scattering on 16O with high energy He‐beams, elastic recoil detection analysis (ERDA), SIMS and nuclear reactions such as H(15N, αγ)12C for H detection, etc.) have been used extensively and successfully in the past years to investigate surfaces and surface‐near layers of materials of importance for nuclear energy. These materials include the nuclear fuels UO2 and UN, the tailor‐made borosilicate glasses and the special ceramics (e.g. SYNROC) for solidification and safe long‐term storage of high level radioactive waste. In this latter area, ion beam techniques have significantly improved the understanding of the mechanisms and kinetics of corrosion in water. Ion beam techniques have also been applied to introduce foreign atoms and to modify the surfaces of these materials, and additional ion beam techniques were subsequently used to analyse the surface changes and modifications. This article presents a review of these largely unpublished activities and points out some of the important progress achieved recently, e.g. on the mechanism of polygonization of UO2.
Interfacial effects of a multifunctional additive on carbon black filled rubber
Authors: Sheng E. , Bradley R. H. , Sutherland I. , Freakley P. K. , Ismail H. 
Published: May 2005

AbstractInterfacial effects of a multifunctional additive (MFA), i.e. n‐tallow‐1,3‐propanediamine salt of a carboxylic acid, on carbon black filled rubber have been studied. Surfaces of several normal cure rate carbon blacks were characterized by XPS and vapour‐phase chemical derivatization, and the carbon blacks were found to have very few functional groups on their surfaces. The MFA has been found to decompose at ∼120 °C and the decomposition generates a diamine and a carboxylic acid. Bound rubber, determined by o‐xylene extraction, was found to decrease with the addition of MFA and a limiting bound rubber value was obtained at the MFA loading which corresponds to a monolayer coverage of the carbon black. The reduction of bound rubber with the addition of MFA is attributed to the release of the occluded rubber within carbon black agglomerates as a result of improved dispersion induced by the MFA. Mechanical properties were found to improve with the addition of MFA and the improvement was again attributed to the dispersing effect of MFA. Optimum mechanical properties were again observed to occur at an MFA loading which approximately corresponds to a monolayer coverage of the carbon black surface.