bluuebunny/crossref_metadata_2025_split huggingface dataset:
An XPS study of the kinetics of dissolution of ZrO2 in α‐Zr
Authors: Prieto P. , Galán L. , Sanz J. M. , Rueda F. 
Published: May 2005

AbstractThe dissolution of a 15 Å thick oxide layer into polycrystalline Zr at temperatures between 440 and 600 K and under non‐oxidizing conditions has been studied by XPS. The thickness of the oxide layer as a function of the annealing time shows a parabolic dependence. It is then concluded that the rate of dissolution is controlled by diffusion into the Zr substrate of oxygen atoms, which generate at the interface by decomposition of the oxide. In addition, the effective oxygen diffusion coefficient in the 440–600 K temperature range has been determined as D = 4.42 × 10−6 exp(−99.7/RT) cm2 s−1, with the activation energy in kJ mol−1.
XPS study of MnO2 minerals treated by bioleaching
Authors: Di Castro V. , Polzonetti G. , Contini G. , Cozza C. , Paponetti B. 
Published: May 2005

AbstractXPS has been used to follow the change of the ore surface composition during bioleaching with a mixed culture of microorganisms. In the original sample, the presence of MnO2 together with silica and alumina is observed. During bioleaching, Mn(IV) is progressively reduced to Mn(II) and signals due to the presence of the microorganisms appear in the C 1s and N 1s spectra.In the residual sample, a considerable amount of Mn associated with the cells of the microorganisms of reprecipitated in the from of the Mn(OH)2 is present on the surface of the ore. This Mn species can be removed completely by treatment with a dilute soultion of HCI.
Quantitative AES: Calibration of spectrometers for true spectral measurements—results of a VAMAS round robin and recommendations for acquiring reference data banks
Authors: Seah M. P. , Smith G. C. 
Published: May 2005

AbstractAs a result of careful calibration, a metrology spectrometer has been developed at the National Physical Laboratory (NPL) to give true spectra. This instrument has been used to measure the true spectra from three reference materials under defined conditions in AES. Measurements for these reference materials, on any other instrument, allow that instrument's intensity–energy response function to be calibrated so that that instrument, in turn, may produce true spectra. In a VAMAS interlaboratory assessment involving 38 respondees, these methods and data have been tested. The results show that AES instruments may be calibrated over the energy range 10–2500 eV to give true spectra to an accuracy in the range 1.5–3.0% in the direct mode and ∼12% in the differential mode. For the first time, all these instruments may be calibrated to give: (1) the same spectra; and (2) spectra in which the instrumental systematic intensity errors are reduced to the above levels.
Application of factor analysis to the AES and XPS study of the oxidation of chromium
Authors: Palacio C. , Mathieu H. J. 
Published: May 2005

AbstractAuger electron spectroscopy (AES), x‐ray photoelectron spectroscopy (XPS) and factor analysis of the MVV Auger spectra and the Cr 2p XPS spectra were applied to study quantitatively the initial stages of the oxidation of polycrystalline chromium. Application of factor analysis allows the identification of up to three real factors. According to the previous works on chromium oxidation, the factors responsible for variations in data were identified as being due to pure metal, chromium oxide (Cr2O3) and chemisorbed oxygen, respectively. The very first stages of the oxidation, <1 L exposures, were found to be characterized by only two factors. Since two standard spectra are known (i.e. metal and chromium oxide spectra), the quantification of all three real factors mentioned above is possible by the application of target testing procedures.
XPS investigation on the corrosion behaviour of nickel in sea water
Authors: Arfelli M. , Ingo G. M. , Mattogno G. , Beccaria A. M. 
Published: May 2005

AbstractThe effect of hydrostatic pressure on nickel corrosion in sea water and in similar solutions has been investigated.By increasing the hydrostatic pressure, the corrosion rate of nickel increases in 0.58 M NaCl and in 0.1 M Na2SO4 and decreases in 0.01 M Na2SO4 and in sea water.This fact is explained by the different nature and composition of the corrosion film grown in these solutions, obtained by XPS, the results of which are compared with electrochemical data.
Surface modifications during Y zeolite dealumination
Authors: Merlen E. , Lynch J. , Bisiaux M. , Raatz F. 
Published: May 2005

AbstractThe external shell formed on a Y zeolite during steaming is shown by XPS to contain both Al and Si extracted from the framework. The progressive formation of SiOH defect groups during steaming and subsequent acid leaching may be followed by binding energy changes and by peak decomposition. The usefulness of the latter for characterization of the chemical environment in silica aluminas is, in this case, limited to suggesting a coherent framework for interpretation of binding energy shifts.
Chemical reactions induced in polymers by keV ions, electrons and photons
Authors: Marletta Giovanni , Catalano Salvatore M. , Pignataro Salvatore 
Published: May 2005

AbstractPolyvinylcarbazole, polyvinylpyridine and polyethersulphone films have been bombarded with 150 keV Ar+ ion beams and the midified surfaces have been characterized chemically by ESCA and REELS (reflection electron energy loss spectroscopy).In the explored fluence range (5 × 1012−1 × 1016 ions cm−2), several types of chemical reactions, such as dehydrogenation, loss of heteroatopms, loss of aromaticity via ring opening, reduction, etc., heve been shown to occur, depending on the chemical structure of the pristine system.For the polyethersulphone, a comparison of the chemical effects produced by electrons, photons and ion beams of comparable energy (∼1 keV) and fluence (1015−10−16 ions cm−2) also has been reported.The results are discussed in terms of energy deposition mechanisms, as well as chemical grounds. In particular, they allow a further assessment to be made of the field of chemical reactions induced by ion beams. Furthermore, they show that for a given dose the chemical modification of a polymer surface by an ion beam is much greater than that expected for electrons or photons.
XPS study of BN thin films deposited by CVD on SiC plane substrates
Authors: Guimon C. , Gonbeau D. , Pfister‐Guillouzo G. , Dugne O. , Guette A. , Naslain R. , Lahaye M. 
Published: May 2005

AbstractBN films deposited from a BF3NH3 precursor, under chemical vapour infiltration conditions, on plane sintered α‐SiC substrates were analysed by XPS. The films are non‐stoichiometric with an N/B atomic ratio of <1. They also contain significant amounts of oxygen atoms, homogeneously distributed in the film and thought to replace partly the nitrogen atoms in the turbostratic hexagonal network. As a result, ternary BNxOy species are formed locally. Near the BN/SiC interface, the oxygen concentration increases owing to the occurrence of ternary SiNxOy species, thought to be the result of an oxinitriding reaction on the substrate surface with the gas phase containing residual oxygen, at the very beginning of the BN deposition process.
Electronic structure of metal–sapphire interfaces
Authors: Gillet E. , Ealet B. , Berlioz J. L. 
Published: May 2005

AbstractWe have investigated metal‐Al2O3 bonding by AES (Auger electron spectroscopy), EELS (energy electron loss spectroscopy) and XPS (x‐ray photoelectron spectroscopy). The metal–alumina interfaces were formed by in situ vapour deposition and we studied the early stages of metal condensation for Pd, Ni, Cr and Zn at room temperature on well‐defined (0001) and (1012) sapphire surfaces. Depending on the treatment, these surfaces exhibit different electronic structures. Upon increasing the metal coverage, new electronic features appear, which point out the role of surface defects (oxygen vacancies, dangling bonds, etc.) during the formation of the first metal monolayer.
Experimental and theoretical XPS study of model molecules for poly(methyl methacrylate)
Authors: Naves de Brito A. , Keane M. P. , Correia N. , Svensson S. , Gelius U. , Lindberg B. J. 
Published: May 2005

AbstractHigh‐resolution C is and O is gas‐phase X‐ray photoelectron spectra of methyl isobutyrate, methyl methacrylate, methyl acrylate, acrylic acid, acetic acid and formic acid have been investigated as model compounds for solid poly(methyl methacrylate) (PMMA). Secondary chemical shifts, variations in peak shapes and intensities for the different core lines were observed. It is shown that asymmetries and differences in line widths of the component peaks should be considered for a correct analysis of the solid polymer spectra. The observed intensities of the different C 1s and O is peaks in the gas‐phase spectra do not follow stoichiometric ratios owing to different shake‐off/shake‐up probabilities. The gas‐phase core electron binding energies have been compared with ab initio ΔSCF calculations where the relaxation of the core‐hole state was included. Using a group shift argument, the relationship between the gas‐phase model molecule shifts and the solid PMMA shifts have been discussed and applied to the analysis of the PMMA spectra.
Mass spectrometry of secondary neutrals and ions for chemical analysis of salts
Authors: Fichtner M. , Lipp M. , Goschnick J. , Ache H. J. 
Published: May 2005

AbstractComplete characterization of solid environmental samples requires sensitive chemical analysis, which includes quantitation of elements, identiflcation of compounds and determination of their spatial distribution. In order to investigate the possible contribution to an analysis of microparticles collected from the atmosphere, plasma‐based secondary neutral mass‐spectrometry (SNMS) and SIMS were examined using salt samples as these are frequent components of such environmental materials. Chlorides, carbonates, nitrates and sulphates were bombarded with high fluxes of argon ions to meet the dynamic conditions for depth‐resolved analysis. This first application of plasma‐based SNMS to salts revealed that their neutral secondary emission mainly consists of those atoms or elements that the bombarded sample is composed of. Thus, mass analysis of the emitted atoms enables the identification of all elements and an example shows that elemental quantitation can be performed with a moderate matrix dependence. A small fraction of binary clusters within the total neutral emission offers compound‐specific information of compounds owing to the emission of characteristic polyatomic ions. Quantitation of the stoichimetry of complex sulphur anions was found to be rather less matrix‐dependent using negative SIMS than SNMS. Although dynamic bombardment inevitably induces chemical reactions, the results demonstrate that depth‐resolved analysis of salt‐containing samples, including elemental quantitation and chemical speciation, can be performed using SNMS and SIMS.
XPS O 1s binding energies for polymers containing hydroxyl, ether, ketone and ester groups
Authors: López Gabriel P. , Castner David G. , Ratner Buddy D. 
Published: May 2005

AbstractXPS spectra of nine model polymers containing oxygen functional groups are studied. The measured O 1s binding energies were 532.8 eV for ether and alcohol oxgens, 532.2 eV for ketone oxygens and 532.2 and 533.7 eV for the carbonyl‐ and ether‐type oxygens in ester groups, respectively. Comparison with previous experimental and theoretical O 1s binding energies for these groups is also presented. Absolute O Is binding energies of polymers are not in agreement with those published by other groups. However, with the exception of ketone oxygens, binding energy shifts observed for the various functional groups are comparable.
Secondary neutral mass spectrometry using a gallium ion probe
Authors: Bishop H. E. , Greenwood S. J. 
Published: May 2005

AbstractAn electron beam pos‐ionization cell has been fitted to the input optics of the quadrupole mass spectrometer of a gallium microprobe secondary ion mass spectrometry (SIMS) instrument. The use of gallium as the primary beam for secondary neutral mass spectrometry (SNMS) has been evaluated. Although much higher probe currents are required for SNMS than for SIMS, no problems have been encountered from gallium retained in the sample. Examples of quantitative analysis of insulating samples and of depth profiles are given.
Auger electron spectroscopy study of the surface segregation in silver–palladium alloys
Authors: Reniers F. , Jardinier‐Offergeld M. , Bouillon F. 
Published: May 2005

AbstractAn AES study of the surface composition of silver–palladium alloys is described. The influence of sulphur contamination, matrix effects and attenuation coefficients on the quantification of the first layer composition is discussed. The experimental Auger data are treated following the Pons et al. model. A weak silver segregation is observed and the results are compared with theoretical models and other experimental studies.
An X‐ray photoelectron spectroscopic investigation of the selectivity of hydroxyl derivatization reactions
Authors: Chilkoti Ashutosh , Ratner Buddy D. 
Published: May 2005

AbstractThe Selectivity of trifluoroacetic anhydride (TFAA), used for the vapor‐phase derivatization of hydroxyl groups in multifunctional oxygen‐containing polymeric surfaces, has been investigated by XPS studies on model epoxides systems. The reactivity of TFAA towards epoxides observed here is discussed in the context of the large amount of published literature implying high selectivity of this reaction towards hydroxyl groups. Acetyl chloride (AcCl) and heptafluorobutyryl chloride (HFBuCl), used to derivatize hydroxyl groups in the literature, were also examined, with regard to cross‐reaction with epoxides. Both AcCl and HFBuCl react with epoxides, forming chloroacetates and perfluorinated chloroacetates, respectively. Moreover, HFBuCl is shown to react with double bonds forming perfluorinated chloroacetates, while AcCl is unreactive towards them. The reactivity of HFBuCl to wards epoxides and unsaturation compromises its use as a derivatization reagent of hydroxyl groups. However, the unique reaction products formed by exposure of hydroxyls and epoxides to AcCl vapor may allow hydroxyl species to be distinguished from epoxides in multifunctional carbon‐oxygen polymeric surfaces.
Application of Tougaard background subtraction to Auger spectra. II. Ti and Co silicides
Authors: Bender H. 
Published: May 2005

AbstractThe application of the Tougaard algorthm for the calculation of the inelastic background of surface electron spectra to the investigation of titanium and cobalt silicides is disecussed. The differential inelastic scattering cross‐section is calculated based on optical or energy loss experiments, derived from REELS spectra or approximated by the ‘Universal cross‐section’. The signal‐to‐noise ratio, the sensitivity for small peaks and sensitivity factors are discussed.
Self‐induced floatability of sulphide minerals: Examination of recent evidence for elemental sulphur as the hydrophobic entity
Authors: Buckley A. N. , Riley K. W. 
Published: May 2005

AbstractRecent evidence, based on spectrophotometric analysis of ethanol extracts, for elemental sulphur being present at the surface of sulphide minerals dry–ground in air has been re–examined. Analysis of ethanol and cyclohexane extracts of ground galena, and electron spectra of abraded galena surfaces, have revealed that while ethanol does extract or leach a sulphur species from galena, sulphur is not present in elemental from on a freshly ground mineral surface.
Low‐energy implantation and sputtering of TiO2 by nitrogen and argon and the electrochemical reoxidation
Authors: Wolff M. , Schultze J. W. , Strehblow H.‐H. 
Published: May 2005

AbstractIn this paper we report the investigation of the implantation and radiation damage during sputter profiles of 30 nm TiO2 layers on Ti with 3 keV N2+. The profiles are analysed by normal and angle‐resolved XPS measurements. Supplementary electrochemical reoxidants are performed, handling the sample without any contact to air during the whole process. Additional information is obtained by comparison with 4 keV Ar+ and 3 keV air sputter profiles.At the beginning of a 3 keV N2+ sputter profile some TiO2 at the surface is converted to TiNxOy, which is only partially oxidizable by repassivation. A portion of the implanted nitrogen exists as molecular N2. After higher sputter dosed the composition changes drastically. Preferential sputtering reduces the oxygen concentration to an extent to allow TiNxO1−x and TiN formation. The TiNxOy changes its composition since it is now fully reoxidizable, as are all compounds with a Ti oxidation state of less than 4 +. N2 reacts with TiNxO1−x by recoil excitation and no longer exists. The occurrence of TiO, Ti2O3 and Ti3N4 is unlikely, but possible in small concentrations. The products of all electrochemical repassivations are TiO2 and N2.Angle‐resolved XPS measurements show Ar‐ and N2‐attenuated surface layers. During Ar and air implantation these layers remain constant owing to an equilibrium between outgassing and implantation of new sputter gas. After nitrogen implantation the N2‐attenuated layers are constant in the beginning and increase when the N2 begins to react with TiNxO1−x until the N2 totally disappears.An addition of oxygen to the sputter gas can decrease the surface roughening effect, which is often found after prolonged sputtering, XPS binding energies show that Ar and N2 gas do not occur in gas bubbbbles.
Sample rotation during depth profiling with secondary ion mass spectrometry
Authors: Vajo John J. , Cirlin Eun‐Hee 
Published: May 2005

AbstractDepth profiles obtained using secondary ion mass spectrometry with O2+ primary ions and without sample rotation have been measured for Mg‐implanted GaAs, B‐ and 2H‐implanted bulk Mo, a deposited Ni/SiO2 interface and for a molecular‐beam‐epitaxy‐grown structure consisting of monolayers of AIAs in GaAs. For the Mg‐implanted GaAs sample profiled without rotation, secondary ion yield changes associated with the development of surface ripples distorted both the matrix an implant profiles. Rotation of the sample during profiling prevented the formation of; surface ripples and, therefore, the associated yield changes. For the bulk Mo sample, surface roughness developed for both rotated and stationary samples. However, with sample rotation, the roughness was considerable reduced and, consequently, depth resolution for the implant profiles was improved. Similarly, the resolution of the Ni/SiO2 interface was greatly increased using sample rotation. For the monolayer AIAs/GaAs sample, profiles were obtained with low primary ion primary ion energy and large angle of incidence with respect to the surface normal in order to optimize the depth resolution. Under these conditions without sample rotation, uneven sputtering by spatially averaging the ion current density, thereby providing good depth resolution of the AIAs monolayers almost without degradation.
Conversion of sputtering time into depth in depth profiles of oxidized CuNi alloys obtained by glow discharge spectroscopy
Authors: Tsuji Kouichi , Hirokawa Kichinosuke 
Published: May 2005

AbstractDepth analyses of oxidized Cu–Ni alloys were performed in the constant voltage mode by glow discharge optical emission spectroscopy. A Cu‐rich oxide was segregated on the surface of Cu–Ni oxidized layer and, moreover, the discharge current varied strongly with the sputtering time. Therefore, it is presumed that the sputtering rate varied with the sputtering time. The dependence of the sputtering rate on the composition of samples was investigated for oxidized Cu–Ni layers in order to convert intensity vs. sputtering time to intensity vs. depth. The region of the Cu‐rich oxide layers in the corrected depth profiles was larger than that in the uncorrected sputtering time profile.
An XPS analysis of different SiO2 modifications employing a C 1s as well as an Au 4f7/2 static charge reference
Authors: Gross Th. , Ramm M. , Sonntag H. , Unger W. , Weijers H. M. , Adem E. H. 
Published: May 2005

AbstractFour different silica modifications—thermally grown SiO2, quartz glass, silicalite and silica gel—have been investigated by XPS. Binding energies for Si 2p, Si 2s and O 1s were obtained by employing different methods of static charge referencing. In any case, a C 1s references was used as usual. In another experiment, deposited 20 nm gold particles were used to provide an Au 4f7/2 binding energy (BE) reference. The two different charging correction procedures result in essentially identical BE data. Furthermore, the results confirm that different modifications of silica give substantially the same relevant BEs in XPS. Though the investigated samples are characterized by quite different concentrations of silanol groups, no significant effect on the measured BEs has been found. On the other hand, the analysed silica samples are observed with quite different Si 2p and O 1s peaks widths. This effect is discussed in terms of differential charging.A rather extensive compilation of XPS literature BEs of silica modifications is given.
Characterization of polycrystalline silicon thin‐film multilayers by variable angle spectroscopic ellipsometry
Authors: Snyder Paul G. , Xiong Yi‐Ming , Woollam John A. , Krosche Eric R. , Strausser Yale 
Published: May 2005

AbstractSamples of polycrystalline silicon (poly‐Si) thin‐film multilayers were prepared by low‐pressure chemical vapor deposition. Analysis of these samples by cross‐sectional transmission electron microscopy (XTEM) revealed large changes in grain size between the undoped–as‐deposited and doped–annealed poly‐Si layers. Roughness at the top of the poly‐Si layers was also observed by XTEM. Non‐destructive variable angle spectroscopic ellipsometry (VASE) was used to characterize these structures and to determine the layer thicknesses and compositions. The poly‐Si and roughness layers were each modeled as physical mixtures, using the Bruggeman effective medium approximation, and incorporated into the appropriate multilayer fitting models. As a result, layer thicknesses and compositions, as well as the surface and interface roughnesses, were determined. The VASE‐obtained thicknesses compared well with those determined by destructive XTEM. The effects on the poly‐Si layer microstructure due to doping and annealing were also characterized.
X‐ray photoelectron spectroscopy and infra‐red studies of X‐ray‐induced beam damage of cellulose, ethyl cellulose and ethyl‐hydroxyethyl cellulose
Authors: Brown Norman M. D. , Hewitt Janet A. , Meenan Brian J. 
Published: May 2005

AbstractThe cellulose derivatives ethyl cellulose and ethyl‐hydroxyethyl cellulose (EHEC) have been studied by XPS in the form of solvent‐cast films. All the films, as well as a sample of cellulose used as a standard material, show significant surface degradation on irradiation in the time period consistent with XPS data acquisition. Under the experimental conditions employed here the four materials studied behave similarly, in that a reaction occurs in the cellulose skeleton, resulting in dehydroxylation of some of the pyranose units in the surface layers, with concomitant elimination of molecules of water.An infrared (IR) analysis of the ethyl cellulose and high‐molicular‐weight EHEC films indicates the presence of a strong carbonyl band, no evidence for which is found in the XPS spectra. However, other features of the IR spectra support the proposed dehydroxylation mechanism. The origin of this inconsistency is nuclear but may be attributable to either differences in the surface and bulk degradation products formed or to the detection differences of the XPS and IR techniques.