bluuebunny/crossref_metadata_2025_split huggingface dataset:
Viscosity effect on GaInSn studied by XPS
Authors: Scharmann F. , Cherkashinin G. , Breternitz V. , Knedlik Ch. , Hartung G. , Weber Th. , Schaefer J. A. 
Published: August 2004

AbstractViscosity measurements of GaInSn eutectic alloys were performed in a homebuilt device for low (9%) and high (95%) relative humidity for shorter (450 min) and longer (1800 min) time periods. At constant exposure time a characteristic increase of viscosity is observed with increasing humidity. For high humidity, high viscosity is obtained after a short time.Assuming that the measured viscosity change is strongly related to the absorption of oxygen, XPS was applied to the chemical and quantitative analysis of differently prepared samples. In all cases, Ga is predominantly oxidized at the surface whereas Ga atoms in the metallic state are located deeper inside. Besides Ga2O3 (the most stable oxide phase), the less stable Ga2O is detected. Indium and tin are almost stable in their metallic state. With increasing humidity the thickness of the oxide film increases in our case from about 19 Å to 25 Å, assuming a layer‐by‐layer model. The presented results confirm our assumption of the increase in viscosity of the GaInSn system as a consequence of the preferential oxidation of gallium in the near‐surface region. Copyright © 2004 John Wiley & Sons, Ltd.
AES characterization of thin oxide films growing on Al foil during oxygen plasma treatment
Authors: Mozetic M. , Zalar A. , Cvelbar U. , Babic D. 
Published: August 2004

AbstractThe oxidation phenomenon during exposure of an Al foil to a low‐pressure weakly ionized oxygen plasma was studied by Auger electron spectroscopy (AES). We used a high‐purity Al foil with a thickness of 10 µm. Prior to plasma experiments the samples were analysed by AES depth profiling. The surface composition slightly varied between samples but, generally, a native impurity film with a thickness of approximately 2.5 nm was found on the Al surface. The surface film consisted of Al, O and C. The chemical state of aluminium was determined from the Al (68 eV) and Al (51 eV) peaks. The samples were exposed to weakly ionized oxygen plasma for various periods up to 300 s. Plasma parameters were measured with Langmuir and optical fibre catalytic probes. The electron temperature was about 70 000 K, the density of charged particles was about 1 × 1016 m−3, and the density of neutral oxygen atoms 2.4 × 1021 m−3. The AES depth profiles of plasma exposed samples showed that even after a short exposure to oxygen plasma a thin but stoichiometric Al2O3 layer was formed. With further exposure to oxygen plasma the thickness of the oxide layers and broadening of the oxide/Al interface increased which was explained by thermal effects. Copyright © 2004 John Wiley & Sons, Ltd.
Ellipsometric and XPS study of the initial oxidation of zirconium at room temperature
Authors: Lyapin A. , Jeurgens L. P. H. , Graat P. C. J. , Mittemeijer E. J. 
Published: August 2004

AbstractThe initial oxidation of polycrystalline zirconium has been investigated with XPS and in situ spectroscopic ellipsometry. Oxidations were performed at room temperature at partial oxygen pressures (pO2) of 1.3 × 10−7, 1.3 × 10−6 and 1.3 × 10−5 Pa. Analysis of the measured Zr 3d XPS spectra revealed the presence of a Zr‐enrichment in the oxide contiguous to the metal/oxide interface, as well as at the oxide surface. Investigation of the oxide‐film growth kinetics at various values of pO2, as determined from both the XPS and the ellipsometry measurements, showed the occurrence of an initial regime of very fast, electric‐field controlled growth, followed by a much slower oxidation stage, ending up with a non‐stoichiometric oxide film of ‘limiting’ thickness. Copyright © 2004 John Wiley & Sons, Ltd.
The oxidation of PbTe(100) surface in dry oxygen
Authors: Yashina L. V. , Tikhonov E. V. , Neudachina V. S. , Zyubina T. S. , Chaika A. N. , Shtanov V. I. , Kobeleva S. P. , Dobrovolsky Yu. A. 
Published: August 2004

AbstractThe oxidation of PbTe(100) surface in dry oxygen was studied by means of XPS. The appearance of a Te+4 component in the Te 3d spectra and an additional component shifted 1.1 eV towards higher binding energies in the Pb 4f spectra was observed. It was revealed that the oxidation mechanism does not change in the range of oxygen exposure 1011–1015 L. The oxidation product stoichiometry is close to PbTeO3. Quantum chemical modelling of the interaction of the small cluster (PbTe)4 with one oxygen molecule was performed by employing the hybrid DFT B3LYP method. It was revealed that PbO (2.22–2.43 Å) and TeO (1.97 Å) bonds are formed during the energetically favourable chemisorption process, giving rise to the increase of Pb and Te effective Mulliken charges by +0.18–0.31e and +1.11e, respectively. These changes are in good correlation with the observed binding energies for additional components in the XPS spectra of the oxidized surface. Copyright © 2004 John Wiley & Sons, Ltd.
SO2 adsorption at room temperature on Ni(111) surface studied by XPS
Authors: Galtayries A. , Cousi C. , Zanna S. , Marcus P. 
Published: August 2004

AbstractThe aim of this work was to investigate the initial stages of the SO2 interaction with Ni(111) surfaces. SO2 adsorption was performed at 1 × 10−7 mbar, at room temperature, in a preparation chamber attached to the XPS analysis chamber. After each adsorption, the S 2p and O 1s core levels were analysed. Various S‐containing adsorbed species were observed: S(ads) located at 162.0 ± 0.2 eV, and SO3(ads) at 166.7 ± 0.2 eV. A weak signal at 163.8 ± 0.3 eV is tentatively assigned to a small amount of SO(ads). The data provided by the O 1s core level spectra have been used to confirm the nature of S‐containing adsorbed species. Changes in the surface concentrations of the different adspecies as a function of exposure indicate that, first, SO2 dissociates into S(ads) and O(ads), then SO2 can either dissociate or combine with the available O(ads) to form SO3(ads). The surface saturation is reached after 12 L. Copyright © 2004 John Wiley & Sons, Ltd.
Epitaxial growth of BaO film on a Ti buffered MgO(100) surface using low‐energy neutral scattering
Authors: Kawanowa Hitoshi , Mori Daisuke , Gotoh Yoshihiko , Souda Ryutaro 
Published: August 2004

AbstractThe atomic structure of the BaO film formed on the Ti buffered MgO(100) surface has been investigated by low‐energy neutral scattering spectroscopy (LENS). The LENS was developed for surface structure and composition analyses particularly of highly insulating materials. The polar angle dependences of scattered He0 intensities indicate that the Ba and O atoms in the BaO unit locate on the missing Ti site and on top of the Ti atom, respectively, in the TiO2 unit formed on the MgO(001) surface and the spacing between the BaO and TiO layers is about 0.15 nm, which is smaller than that of BaTiO3 (c/2 = 0.20 nm) by 0.05 nm. Copyright © 2004 John Wiley & Sons, Ltd.
Characterization of iron oxide thin films
Authors: Aronniemi Mikko , Lahtinen Jouko , Hautojärvi Pekka 
Published: August 2004

AbstractIron oxide thin films were grown with gas‐phase deposition on a glass substrate in order to study the effects of the deposition temperature and time on the film properties. Characterization of the samples was performed using x‐ray photoelectron spectroscopy, x‐ray diffraction, and atomic force microscopy. It was observed that the film deposited at 350°C consisted of γ‐Fe2O3 whereas films produced at temperatures between 400°C and 500°C could be identified as α‐Fe2O3. Increasing the deposition temperature resulted in an increase of the grain size at temperatures between 350°C and 450°C. When the deposition time was decreased, a part of the iron ions were observed to be in the divalent state. Copyright © 2004 John Wiley & Sons, Ltd.
Preparation of ultrathin HfO2 films and comparison of HfO2/SiO2/Si interfacial structures
Authors: Tan R. Q. , Azuma Y. , Fujimoto T. , Fan J. W. , Kojima I. 
Published: August 2004

AbstractStoichiometric HfO2 films were successfully prepared using both thermal oxidation of Hf metal film and direct reactive sputtering deposited on native SiO2/Si wafer. Angle‐resolved x‐ray photoelectron spectroscopy, Auger depth profiling and grazing incident x‐ray reflectivity have been exploited to study the interfacial structures of the generated HfO2 films. A thinner interface (about 1.2 nm) of Hf‐rich silicates is formed using thermal oxidation, while the reactive sputtering deposition leads to a thicker (about 3.2 nm) Si‐rich interface. The results of binding energy, chemical composition, thickness and density all indicate that both interfaces have a graded structure where the concentration of Hf in the silicate interlayer decreases gradually along the depth. Copyright © 2004 John Wiley & Sons, Ltd.
Oxidation behaviour of Al‐alloyed ductile cast irons at elevated temperature
Authors: Kiani Rashid A. R. , Edmonds D. V. 
Published: August 2004

AbstractThe oxidation resistance of ductile irons alloyed with aluminium in the range from 0.08 to 6.16 wt.% has been investigated by heating at 550°C for periods up to 1270 h. Examination by light and SEM microscopy and EPMA indicated that two quite distinguishable layers of oxide were established at the surface. It was found that, in alloys containing aluminium, a very thin and adherent film of aluminium oxide is produced after a short period of heating, which protects the bulk of the alloy from further attack. It is believed that the oxidation resistance can be improved by increasing the aluminium content: an increase in aluminium content led to a decrease in the average thickness of the iron‐rich oxide layer. It was also found that the Al addition improved decarburization resistance; after long times at 550°C a nodular iron with a 6.16% Al content was free of decarburization. Copyright © 2004 John Wiley & Sons, Ltd.
Determination of the oxidation kinetics of modified α‐iron substrate: correlation between TGA and AES
Authors: Grosseau‐Poussard J. L. , Panicaud B. , Dinhut J. F. , Lahaye M. , Silvain J. F. 
Published: August 2004

AbstractA conversion phosphating treatment has been performed on polycrystalline α‐iron in order to modify its thermal oxidation behaviour. This has been studied by means of in situ thermogravimetric experiments and line profile nanoscale AES of the phosphated surface layer, both before and after the oxidation experiments. Modifications of the α‐iron oxidation mechanisms and their correlations with the evolution of the oxidation kinetics of α‐iron under the influence of phosphate films are evidenced in this work. Copyright © 2004 John Wiley & Sons, Ltd.
Reproducible XPS on biopolymers: cellulose studies
Authors: Johansson Leena‐Sisko , Campbell J. M. 
Published: August 2004

AbstractThe development of ‘user‐friendly’ surface analytical instrumentation has expanded the application of x‐ray photoelectron spectroscopy (XPS) towards softer and more complex composite materials. However, the knowledge of fundamental phenomena in practical, interdisciplinary applications is dearly needed. In the case of polymers and polymer‐based or ‐reinforced composites, the analytical problems are not only related to detection limits and resolution; indeed, the effects of contamination and experimental artefacts on interpretation of the carbon signal are often the more crucial challenge.As a biopolymer, natural cellulose fibres provide an interesting model system for polymer studies. Numerous published XPS studies on lignocelluloses highlight both the possibilities and the problems of the surface analytical probes in analysis of air‐exposed organic materials.We report XPS experiments of cellulosic natural fibre materials, discussing the effects of sample storage, UHV exposure, radiation doses, charging and data analysis. Based on a large body of experimental data we also propose that clean paper specimens could be used as an in‐situ reference in polymer studies. Copyright © 2004 John Wiley & Sons, Ltd.
Labelling techniques for the chemical analysis of polymer surfaces
Authors: Holländer Andreas 
Published: August 2004

AbstractThe labelling of functional groups for the surface analysis of polymers has been developed to become a useful tool. We briefly review examples which show the power improvement of a number of instrumental techniques for the analysis of chemically complex surfaces.The application of labelling techniques to some real‐world samples is demonstrated with some examples. The relation between labelling for XPS and for a fluorescence determination is shown with an oxygen plasma treated polyethylene. It was reacted with diaminoethane (DAE) and with fluorescamin or with dansyl hydrazine. The sensitivity of the fluorescence labelling is about two orders of magnitude higher. The robustness of the fluorescence labelling technique is shown by an orthogonal coupling. The subsequent coupling of two types of dyes to two different functional groups does not influence the fluorescence intensity of each dye. Copyright © 2004 John Wiley & Sons, Ltd.
Surface characterization of plasma‐treated PTFE surfaces: an OES, XPS and contact angle study
Authors: Vandencasteele N. , Reniers F. 
Published: August 2004

AbstractPTFE surfaces have been exposed to neutral atoms and molecules, and to electrons originating from a modified RF nitrogen plasma, able to filter out the cations. The changes in surface energy of the modified polymer, determined by the water contact angle, are linearly related to the increase of the nitrogen concentration at the surface, determined by XPS. The deconvolution of the spectral envelope of the C 1s photoelectron peak shows a strong modification of the nature of the chemical groups on the surface, depending on the treatment time and on the plasma power. Electrons are postulated to be mainly responsible for the appearance of the CF3 group, while the major functions induced by nitrogen seem to be CN, CN and a possible FCN group. Copyright © 2004 John Wiley & Sons, Ltd.
Interface analysis and compositional depth profiling by XPS of polymer coatings prepared using ultra‐low‐angle microtomy
Authors: Hinder Steven J. , Watts John F. , Lowe Chris 
Published: August 2004

AbstractConventional rotary microtomy in combination with high‐precision, ultra‐low‐angle sectioning blocks have been used to produce cross‐sectional, ultra‐low‐angle tapers in polymeric coating systems. Tapered samples produced by ultra‐low‐angle microtomy (ULAM) have been employed in the investigation of intercoat bonding interfaces in multilayer polymeric coatings and for the compositional depth profiling of polymer/polymer + additives systems.X‐ray photoelectron spectroscopy (XPS) cross‐sectional analysis of a poly(vinylidene difluoride) (PVdF) based topcoat and a poly(urethane) based primer interface exposed by ULAM processing indicates diffusion of fluorine‐containing components of the PVdF topcoat formulation into the uppermost nanometres of the underlying poly(urethane) primer. It is demonstrated that a ULAM exposed, cross‐sectional multilayer interface, with a taper of <0.05°, investigated by high‐resolution XPS employing a 15 µm spot‐size enables the interface region to be probed at a depth resolution of <20 nm.Depth profiling characterization by XPS of a polyamide powder coating with an organosilane adhesion promoter reveals a silicon concentration gradient within the cured polymer. This result demonstrates that the organosilane preferentially segregates to the surface regions of the cured polymer coating system. Copyright © 2004 John Wiley & Sons, Ltd.
Synthesis and characterization of viologen‐containing poly(vinylidene fluoride) redox‐sensitive membranes
Authors: Liu X. , Neoh K. G. , Kang E. T. 
Published: August 2004

AbstractThermally induced graft co‐polymerization of 4‐vinylbenzyl chloride (VBC) with ozone‐preactivated poly(vinylidene fluoride) (PVDF) was carried out in N‐methyl‐2‐pyrrolidone solution to produce VBC‐g‐PVDF co‐polymers. The resulting VBC‐g‐PVDF co‐polymers with different VBC graft concentrations were cast into microfiltration membranes by phase inversion. Viologen moieties were introduced by the di‐quaternization of 4,4′‐bipyridine with the VBC‐g‐PVDF membranes and VBC through a two‐step reaction in ethanol. The viologen‐containing membranes were characterized by x‐ray photoelectron spectroscopy, elemental analysis, and thermogravimetric analysis. Surface morphology was studied by scanning electron microscopy. It was demonstrated that the permeability of the viologen‐containing membrane can be regulated by redox reactions. This technique of fabricating viologen‐containing membranes represents a relatively simple and effective approach for achieving membranes with redox‐sensitive permeation properties. Copyright © 2004 John Wiley & Sons, Ltd.
Fast atom beam treatment of ultra‐high molecular weight polyethylene
Authors: Tóth A. , Ujvári T. , Bertóti I. , Szilágyi E. , Keszthelyi T. , Juhász A. 
Published: August 2004

AbstractUltra‐high molecular weight polyethylene (UHMWPE) was surface treated by beams of various inert and reactive atoms in the low keV range. Sum frequency generation (SFG) spectroscopy showed the complete destruction of ordered packing at the topmost surface. Rutherford backscattering (RBS) and elastic recoil detection analysis (ERDA) revealed a strong surface dehydrogenation. Depth‐sensing nano‐indentation and nanoscratch measurements testified to alterations in the nanomechanical properties. A correlation has been established between the scratch resistance and the plasmon loss energy of the C 1s XPS peak. Copyright © 2004 John Wiley & Sons, Ltd.
Optical and mechanical properties of polypropylene modified by metal oxides
Authors: Kruenate J. , Tongpool R. , Panyathanmaporn T. , Kongrat P. 
Published: August 2004

AbstractFilms of polypropylene (PP)/SiO2, PP/ZnO and PP/SiO2ZnO nanocomposites have been prepared. SiO2 and ZnO were prepared by the sol–gel method and mixed with dispersant (Efka) and coupling agent (thiocyanatopropyltriethoxysilane) before being introduced to melted PP in an internal mixer. The transmission of UV, visible light and NIR radiation of the nanocomposite films was less than that of the PP films. Efka and silane made the film clearer to all rays since they hindered the particle agglomeration. PP/ZnO film had a unique property as it blocked UV while transmitted visible light better than PP/SiO2. The modulus of PP mixed with metal oxide increased whereas the elongation to break decreased, indicating that the metal oxides increased the film strength and brittleness. The PP/SiO2 gave higher tensile strength and modulus than the PP/ZnO due to the greater hardness of SiO2. The silane improved the tensile strength and modulus of PP/SiO2. Copyright © 2004 John Wiley & Sons, Ltd.
Surface and interface characterization of smart membranes
Authors: Zhai Guang‐Qun , Ying Lei , Kang E. T. , Neoh K. G. 
Published: August 2004

AbstractMultistimuli‐responsive microfiltration (MF) membranes were fabricated from blends of poly(N‐isopropylacrylamide) (PNIPAm) and poly(vinylidene fluoride) (PVDF) grafted with poly(acrylic acid) (PAAc) and poly(4‐vinylpyridine) (P4VP) side‐chains (PVDF‐g‐PAAc/PNIPAm and PVDF‐g‐P4VP/PNIPAm, respectively) by phase inversion in aqueous media. Elemental and XPS analyses indicated that both the bulk and surface concentration of PNIPAm in the PVDF‐g‐PAAc/PNIPAm and PVDF‐g‐P4VP/PNIPAm blend membranes increased with increasing PNIPAm concentration in the blend used for the casting solution. Surface enrichment of the PNIPAm chains occurred in both types of membrane, leading to a surface concentration ten times that of the bulk. SEM results showed that the porous morphology of the membranes could be regulated by the pH and temperature of the coagulation bath. Actual measurements revealed that the pore size of the PVDF‐g‐P4VP/PNIPAm blend membranes increased with the increase in temperature and the decrease in pH of the aqueous casting bath. The flux through the PVDF‐g‐PAAc/PNIPAm and PVDF‐g‐P4VP/PNIPAm blend membranes exhibited simultaneously temperature‐ and pH‐dependent behaviour. Copyright © 2004 John Wiley & Sons, Ltd.
The influence of the ion distribution on interfacial effects in oligoether functionalized poly(p‐phenylene) based mixed ionic electronic conductors
Authors: Wenzl F. P. , Suess C. , Poelt P. , Mauthner G. , List E. J. W. , Bouguettaya M. , Reynolds J. R. , Leising G. 
Published: August 2004

AbstractWe report on surface composition studies of thin spin‐cast films of a polymeric mixed ionic electronic conductor (PMIEC). The polymeric constituent consists of a hydrophobic conjugated poly(p‐phenylene) (PPP) backbone functionalized with hydrophilic oligo(ethylene oxide) (OEO) side‐chains to supply the electronically conducting conjugated polymer with an ion transporting functionality. In particular a lithium salt (lithium trifluoromethanesulfonate), the prototype salt applied in solid‐state electrolytes, was chosen for the investigations.Identification of the elements and their quantification was done by XPS for different salt concentrations in order to address the still open question of surface‐induced effects on the ion distribution in thin films of solid‐state electrolytes. No enrichment or depletion of the ionic species at the free surface could be observed for the concentrations investigated within the error of the measurement given. Copyright © 2004 John Wiley & Sons, Ltd.
Surface excitation of selected conducting polymers studied by elastic peak electron spectroscopy (EPES) and reflection electron energy loss spectroscopy (REELS)
Authors: Gergely G. , Menyhard M. , Sulyok A. , Orosz G. T. , Lesiak B. , Jablonski A. , Tóth J. , Varga D. 
Published: August 2004

AbstractElectrons impinging into a solid surface produce excitations in the surface layer. The elastic reflection coefficient of a solid (i.e. elastic peak) is reduced by surface losses. Selected conducting polymers were studied with elastic peak electron spectroscopy (EPES) and reflection electron energy loss spectroscopy (REELS). The electron inelastic mean free path (IMFP) was determined using EPES with Ag and Si references and corrected for surface excitations, characterized by the surface excitation parameter Pse(E). A new procedure was developed for experimental determination of the parameter Pse(E), a further development of Tanuma's work. It is based on comparison of experimental and calculated integrated elastic peak ratios of sample and reference. Another procedure was based on the REELS method. Pse(E) of selected polymers were determined for E = 0.2–2.0 keV using a HSA analyser. Experiments were evaluated by Monte Carlo simulation using NIST elastic scattering databases. The IMFP values for polymers were calculated by Gries, Cumpson and TPP‐2M formulae. Material parameter data, ach, using Chen's approach for selected polymers, and IMFPs of polyethylene corrected for surface excitation are presented. Copyright © 2004 John Wiley & Sons, Ltd.
Polymerization of aniline in the channels of micro‐ and mesoporous materials
Authors: Márquez F. , Roque‐Malherbe R. , Ducongé J. , del Valle W. 
Published: August 2004

AbstractPreparation of conducting polymers incorporated within porous materials, that is, zeolites and mesoporous materials, is an attractive methodology to obtain composite materials where the organic polymer may exhibit an increased mechanical and chemical performance compared to the pure polymer. For any application, a crucial issue is the polymer content of the resulting composite material. In fact, a major limitation of the use of hosts has been up to now the low loading of conducting polymer that has been achieved. Based on the composition of related composite materials, a weight percentage of the organic polymer of at least 25% should be attained. We now report the polymerization of aniline within the pores of aluminosilicates and the characterization of the encapsulated polymer/host composites. These composites have potential as stable molecular wires and their applications in the design of batteries and systems to accumulate electric charge are currently being developed. Copyright © 2004 John Wiley & Sons, Ltd.