bluuebunny/crossref_metadata_2025_split huggingface dataset:
Wettability and interfacial reactions in Al/TiO2
Authors: Sobczak N. , Stobierski L. , Radziwill W. , Ksiazek M. , Warmuzek M. 
Published: August 2004

AbstractThe effects of temperature and testing procedure on the wetting properties of molten Al on polycrystalline TiO2 substrates were studied by a sessile drop method in vacuum at 1173–1373 K. For the common contact heating procedure, oxidized molten Al wets titania at T > 1210 K. The removal of the oxide film from the Al drop by means of a capillary purification procedure makes the Al/TiO2 couple wettable at 1173 K. The structure and chemistry characterization of Al/TiO2 interfaces shows that molten Al reacts with TiO2 to form fine alumina particles and Ti, which subsequently is dissolved in the Al drop. However, this reaction is remarkable at 1373 K only and much higher temperatures are required for successful reactive synthesis of Al/Al2O3 composites. Copyright © 2004 John Wiley & Sons, Ltd.
Influence of doping on the surface feature and formation of PbI2 polytypes
Authors: Soudmand M. , Habibi S. 
Published: August 2004

AbstractA study of phase transformation at elevated temperature has been undertaken on single crystals of lead iodide grown in gel. The crystals of the polytype 2H, which is known to be the common modification of PbI2 at room temperature, have been found to transform into well‐ordered crystals of the polytype 12R after heating for nearly 8 h at 150°C. During the intermediate period of heating the crystals show features of disorder, viz. streaking, arcing, or both, on their x‐ray diffraction photographs. On the other hand, the higher polytypes do not show any change in cell dimensions even after prolonged heating. In addition, it was found that if silver iodide is added in extremely minute quantities as an impurity during crystallization the process of phase transformation in the as‐grown crystals appreciably accelerates. Inspection by optical microscopy of these crystals has revealed the existence of a wide variety of growth features on their basal surfaces. The results have been discussed in detail. Copyright © 2004 John Wiley & Sons, Ltd.
Chemical speciation of N‐(phosphonomethyl)glycine in solution and at mineral interfaces
Authors: Ramstedt Madeleine , Norgren Caroline , Sheals Julia , Shchukarev Andrei , Sjöberg Staffan 
Published: August 2004

AbstractThe chemical speciation of the zwitterionic compound N‐(phosphonomethyl)glycine (PMG) was studied in solution and at the mineral/water interface at different pH. Results from vacuum techniques such as XPS were compared with previously published conventional batch experiments. It was shown that by keeping the samples frozen during XPS analyses it was possible to keep a water interface. The frozen interface enables studies of the protonation of the nitrogen group which has previously been difficult using XPS. The protonation in frozen solutions was compared with literature data and the differences discussed. Furthermore, the speciation of PMG at the surface of manganite (γ‐MnOOH) and goethite (α‐FeOOH) was studied. It was found that at least one of the protonation constants for surface‐bound PMG differs significantly from the protonation constants in a pure PMG solution. The formation of different surface complexes is discussed together with differences between the sorption capacities of PMG onto the minerals studied. Copyright © 2004 John Wiley & Sons, Ltd.
Surface composition of CuAu single crystal electrodes determined by a coupled UHV–electrochemical approach and a Monte‐Carlo simulation
Authors: Pace S. , Van Hoof T. , Hou M. , Buess‐Herman C. , Reniers F. 
Published: August 2004

AbstractRecent papers show that copper could act as an electrode capable of electrocatalysing the reduction of carbon dioxide, a major greenhouse gas. However, no fundamental studies on single crystals have been related, and although the presence of surface oxides seems to be important, little is known about the mechanism.Single crystal electrodes of Au, Cu and AuCu alloys (1, 10, and 20 at.% gold) and a 50 at.% gold polycrystal alloy have been synthesized and characterized by AES and cyclic voltammetry (CV). The segregation equilibrium was studied experimentally (using the low‐energy Auger peaks of Cu and Au after deconvolution) and theoretically (with classical thermodynamics and a Monte‐Carlo Metropolis approach). All the alloy electrodes show a surface enrichment in gold. The electrochemical characterization reveals that the dilution of copper by gold delays the oxidation of the electrode to more positive potentials with respect to pure copper, whereas simultaneously the reduction of protons occurs at more negative potentials than pure gold. Thanks to an electrochemical–UHV transfer system, we show that the surface composition of the electrode drastically depends on the working potential. Copyright © 2004 John Wiley & Sons, Ltd.
The connection between hydrogen diffusion through a steel membrane and mechanism of the hydrogen evolution reaction
Authors: Tsygankova L. E. , Vigdorovich V. I. , Vigdorovich M. V. 
Published: August 2004

AbstractThe kinetics of the hydrogen evolution reaction (HER) on Armco iron and carbon steel have been studied in the C2H4(OH)2H2OHCl system. The addition of 5–10% water or 1–10 mM Na2HAsO4 to the ethylene glycol solutions of HCl causes a transition from the Volmer rate determining step (rds) to the Tafel rds in the HER mechanism. According to experimental data, the rate of hydrogen diffusion through the carbon steel membrane does not depend on the rds nature of the HER. Theoretical analysis of the peculiarities of the Tafel rds has been carried out in which a recombination step was represented as a set of successive reactions. An expression has been obtained which determines the balance of surface processes and the hydrogen permeation into the bulk of the metal. It has been confirmed experimentally. Copyright © 2004 John Wiley & Sons, Ltd.
Calibration of various analytical methods with heavy‐ion ERDA
Authors: Bohne W. , Lindner S. , Röhrich J. , Strub E. 
Published: August 2004

AbstractHeavy‐ion ERDA (elastic recoil detection analysis) can be used to characterize thin solid layers. Absolute concentrations of the chemical elements can be detected as well as the layers' thickness and depth profiles. For the measurement, the sample is irradiated with a heavy‐ion beam. Atoms of the sample are recoiled and detected with an energy and mass dispersive spectrometer. Since the ERDA principle is based on the classical Rutherford scattering theory, the expected yields for the given conditions can be calculated exactly. Therefore, ERDA is a standard‐free method. Absolute concentrations can be determined for all detected chemical elements simultaneously. By comparison with ERDA measurements an FT‐IR (Fourier transform–infrared) spectrometer, routinely used to determine the stoichiometry of ZnO layers, was calibrated. Artefacts in SIMS (secondary ion mass spectrometry) data for the characterization of chalcopyrite based solar cell absorbers are ruled out. Copyright © 2004 John Wiley & Sons, Ltd.
AES analysis of nitride layers on steel with target factor analysis
Authors: Vandendael I. , Steenhaut O. , Hubin A. , Vereecken J. , Prince P. , Reniers F. , Segato T. 
Published: August 2004

AbstractIndustrially nitrided steel samples are analysed with AES. The aim of this work is to optimize the quantification of nitrogen and to extract the chemical information hidden in the shape of the measured Auger peaks with Target Factor Analysis (TFA).To optimize the use of TFA, reference samples of pure components are necessary. These components are made in a laboratory reactor in which pure iron is nitrided. The resulting nitride layer is identified with X‐Ray Diffraction (XRD). Afterwards their AES spectra are taken as input for the TFA of the industrial layers. In this paper, the preparation and the characterization of a γ′‐Fe4N standard is discussed, as well as the correction of the sensitivity factors used for the quantification of nitrogen. Finally, the application of TFA on an industrial nitride layer is discussed. Copyright © 2004 John Wiley & Sons, Ltd.
Experimental measurements of the surface excitation parameters of Cu, Au, Ni, Ag, Ge and Pd based on Si and other reference standard materials
Authors: Gergely G. , Menyhard M. , Gurban S. , Toth J. , Varga D. 
Published: August 2004

AbstractSurface excitation in electron spectroscopy is characterized by the surface excitation parameter Pse. In electron spectroscopy, the total surface excitation is observed for electrons impinging and reflected elastically (elastic peak electron spectroscopy, EPES) or for backscattered (REELS) electrons. Surface excitation reduces the intensity of the elastic peak and affects the REELS spectra. Experimental determination of the total Pse from EPES spectra is made by measuring the ratio of integrated elastic peak intensities for the sample Iese and reference material Iere. This paper presents further development of Tanuma's work for this ratio. Pser of the reference was calculated with the formula and material parameters of Chen. Monte Carlo simulations were based on the NIST elastic scattering and Tanuma's IMFPs database for the reference samples. This work deals with Cu, Au, Ag, Ni and Pd metals and Ge, used also as standards for electron spectroscopy. Experiments were made with a high‐energy resolution spectrometer (HSA), and with a DESA 100 spectrometer (Staib Ltd) with large solid angle for E = 0.2–2 keV. Surface excitation correction factors have been developed for the above metals and Ge, used for reference samples. Their application reduced the differences in IMFPs from Tanuma's values for the uncorrected rms errors Δλu (% values) to Δλc (corrected) data for Si/Ag (from 21.2 to 6.7%), for Si/Ni (11.4 to 9.8%), and for Si/Cu (13.5 to 5%). A similar improvement was found for Si/Au, Ag/Ni, Ag/Cu and Ag/Au experimental results, using surface excitation correction. Copyright © 2004 John Wiley & Sons, Ltd.
Instrument for thin film diagnostics by UV spectroscopic reflectometry
Authors: Urbánek M. , Spousta J. , Navrátil K. , Szotkowski R. , Chmelík R. , Buček M. , Šikola T. 
Published: August 2004

AbstractThis paper describes the principles, design and testing of an instrument for the UV/Vis‐optical‐reflectance monitoring of homogeneity of the optical properties of thin films developed in our group. A 200 µm reflection probe, miniature fibre optic spectrometer and a home‐built computer controlled x–y mapping stage together with original data fitting software are the principal parts of the instrument. The results achieved show the usability of this instrument for the post‐production testing of samples of various optical thin films prepared by different technologies. By this instrument the gradients and other inhomogeneities of thickness and spectral optical constants (n, k) of thin films can be monitored. Copyright © 2004 John Wiley & Sons, Ltd.
The effect of bias voltage on the measurement of local barrier height
Authors: Yoshitake Michiko , Yagyu Shinjiro 
Published: August 2004

AbstractThe effect of experimental conditions on local barrier height (LBH) measurement with the STM technique was examined based on Simmons' formula. It has been revealed that the effect of bias voltage on LBH has to be measured under constant tip–specimen separation, not under constant tunnel current as normally used, because tip–specimen separation varies with bias voltage under constant current condition. We propose to start LBH measurement with I–V curve measurement and vary bias voltage along the I–V curve so that the tip–specimen distance is kept constant. We also propose to use the I–V curve to choose an equation suitable for LBH calculation in a specific bias voltage. The formula applicable for each bias voltage has been given. Copyright © 2004 John Wiley & Sons, Ltd.
Distinguishing the dependence of the apparent local barrier height on measurement conditions
Authors: Yagyu Shinjiro , Yoshitake Michiko 
Published: August 2004

AbstractWe have investigated a method for finding the dependency of the apparent local barrier height (LBH) on measurement parameters (tunnelling current, bias voltage and tip–sample separation). The validity of the method is demonstrated by measuring the LBH on an Au(111) surface. This method enables comparison of LBH values on various surfaces. Copyright © 2004 John Wiley & Sons, Ltd.
Multivariate characterization of ultra‐thin nanofunctional plasma polymer films using ToF‐SIMS analysis
Authors: von Gradowski M. , Wahl M. , Förch R. , Hilgers H. 
Published: August 2004

AbstractOctadecanethiol self‐assembled monolayers (SAMs) on gold substrates have been exposed to an allylamine plasma for different plasma times ranging from 0 to 9 min. Time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS) positive spectral fragmentation patterns of SAM‐allylamine plasma films of varying allylamine deposition times were analysed using multivariate techniques (PCA and PLS). Multivariate data analysis permits the exploration of the entire spectrum by forming the best linear combination of the principal components which describes the maximum amount of variance of the sample set. PLS‐models have been calculated correlating spectral parameters to sample properties such as layer thickness and atomic concentration of selected ions. The predicted sample properties were in good agreement with the experimental results showing that the combination of ToF‐SIMS analysis with multivariate techniques is an efficient way of sample characterization and interpretation of spectral data and should be the method of choice for future spectral data analysis. Copyright © 2004 John Wiley & Sons, Ltd.
Optimization of x‐ray monochromating systems: application to LiF(220) crystal with Johansson geometry for Cu K (8047.78 eV)
Authors: Moslemzadeh N. , Watts J. F. , Tsakiropoulos P. , Beamson G. , Haines S. , Weightman P. 
Published: August 2004

AbstractThe design of monochromated x‐ray sources for high‐energy XPS is of particular importance. Prediction of the final result and the effect of the experimental parameters is very important if optimum performance is to be obtained in practice. A computer program has been written to calculate crystal reflectivity, collection solid angle and integrated beam intensity for any singly and doubly bent crystal diffractor. The intensity profile, size and shape of the image‐spot produced by the diffracted x‐rays on any arbitrary plane are then predicted by ray tracing. The application of the program to optimize a LiF(220) crystal with Johansson geometry for Cu K (8047.78 eV) will be demonstrated. Copyright © 2004 John Wiley & Sons, Ltd.
Modified chromatographic thin layer surface as an interface to couple thin layer chromatography with ToF‐SIMS
Authors: Oriňák Andrej , Arlinghaus Heinrich F. , Vering Guido , Oriňáková Renáta 
Published: August 2004

AbstractThe goal of our research is the development of a new interface to combine thin layer chromatography (TLC) with time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS). The direct combination of the simple separation technique (TLC) with the highly selective identification unit (ToF‐SIMS) requires a modification of common TLC material to reduce the background signal in SIMS spectra. The background signal is caused either by the stationary phase or by the residual mobile phase (solvent). The aluminium back of the TLC layer has been modified to get a universal porous TLC–ToF‐SIMS interface. Functionality of this novel interface has been tested with a Methyl Red indicator as a representative analyte to visualize its transport through the chromatographic layer and interface. From ToF‐SIMS results it was found that the indicator molecule fragments at the diazo double bond NN. Copyright © 2004 John Wiley & Sons, Ltd.
Electron beam irradiation of hydrogenated amorphous carbon films
Authors: Calliari L. , Filippi M. , Laidani N. 
Published: August 2004

AbstractThe effect of electron irradiation on hydrogenated amorphous carbon (a‐C:H) films is investigated on both as‐deposited and thermally annealed films and is compared to the effect of thermal annealing. As for the as‐deposited film, both electron irradiation and thermal annealing result in a change in the film structure from diamond‐like to graphite‐like. In the case of electron irradiation, such a phase transformation proceeds in a logarithmic way as a function of the electron dose. No electron‐induced effect is observed on previously annealed films. Copyright © 2004 John Wiley & Sons, Ltd.
Sol–gel synthesis and characterization of iron oxide–silica nanocomposites
Authors: Tongpool R. , Jindasuwan S. 
Published: August 2004

AbstractThe films of iron oxide–silica nanocomposites have been prepared using the sol–gel process and spin‐coating technique. The film morphology was dependent on precursors, additives, ageing duration and the molar ratios between iron (Fe) and silicon (Si) of the coating solution. Hematite was derived from iron oxide sol while those obtained from silica and iron oxide–silica sols were relatively amorphous, indicating that crystallization and particle growth of hematite were inhibited by the silica network. Hydroxypropylcellulose (HPC) was found to reduce cracks successfully. It increased the film porosity and did not interrupt the crystallization of the host. The film containing a Fe:Si:HPC ratio of 50:50:0.005 showed the smoothest surface. Copyright © 2004 John Wiley & Sons, Ltd.
Epitaxial growth of sub‐nanometre thick tin dioxide films on sapphire substrates by pulsed atomic layer chemical vapour deposition
Authors: Takeuchi Toshio , Doteshita Isao , Asami Seiji 
Published: August 2004

AbstractSub‐nanometre thick tin dioxide (SnO2) films were grown on both amorphous Pyrex glass and crystalline CZ sapphire substrates using pulsed atomic layer metal‐inorganic chemical vapour deposition. The source materials, SnCl4 and H2O, were introduced by pulsed doses as reactants into the cold reactor, and doses were separated by pulse doses of inert purge gas doses. Depositions took place at a reduced pressure 2.5 × 10−2 Torr at the temperature range 400°C to 500°C. X‐ray diffraction analysis (XRD), ultraviolet photoelectron spectroscopy (UPS), XPS and spectrophotometry were used to characterize the films. The crystal structure of the grown films were rutile type, as with the single crystals. During the one growth operation, films with a SnO2(100) crystal surface were epitaxially grown on the sapphire(0001) substrates and films with a SnO2(101) crystal surface were epitaxially grown on the sapphire(1‐102) substrates at the same deposition processes. Copyright © 2004 John Wiley & Sons, Ltd.
X‐ray photoelectron spectroscopic analysis of growth and thermal stability of palladium ultra thin films on alumina/NiAl(110)
Authors: Song Weijie , Yoshitake Michiko , Lay Thi Thi 
Published: August 2004

AbstractWe have studied the growth and thermal stability of Pd ultra‐thin films on Al2O3/NiAl(110) in situ using x‐ray photoelectron spectroscopy. The results showed that Pd grew in a nearly layer‐by‐layer manner on the Al2O3/NiAl (110) surface at a deposition rate of 0.2 Å/min. No strong interaction between the Pd over‐layer and the substrate was observed during initial growth. After high‐temperature treatments, Pd diffused into the substrate and the alumina layer thickness increased significantly. Palladium served as a catalyst for this reaction when the temperature was lower than 570 K; PdO formed when the temperature was higher than 670 K. Copyright © 2004 John Wiley & Sons, Ltd.
Characterization of AgAsS and AgSbS amorphous films prepared by pulsed laser deposition
Authors: Wagner T. , Krbal M. , Gutwirth J. , Nemec P. , Vlcek Mir. , Frumar M. , Perina V. , Mackova A. , Hnatovitz V. , Kasap S. O. , Vlcek Mil. 
Published: August 2004

AbstractThin amorphous films of AgAsS and AgSbS systems have been prepared by pulsed laser deposition (PLD) at five different conditions, i.e. at different pulse energies and pulse repetition intervals of the KrF laser. The obtained films were analysed by RBS, ERDA (elastic recoil detection analysis) spectral analysis and also EDXA elemental analysis. The results of RBS and EDXA analysis were compared to the composition of the source bulk glass materials. Film compositions varied compared to the source material according to the deposition condition with film composition close to the stoichiometric one, i.e. AgAsS2 and AgSbS2 could be prepared by the PLD technique. RBS spectroscopy is known as an important tool for establishing depth distribution of the elements within the prepared films. The thickness of the films was chosen so that depth profiling of the entire layer is possible. ERDA allowed us to find, apart from all obvious atoms (Ag, As, Sb, S), also H atoms present in the films. The structure of the films has been studied by Raman spectroscopy as well. Vibration bands characteristic of As(Sb)S2AgAs(Sb)S2 structural units present in prepared films have been observed. The films are potentially applicable for optical memories (e.g. digital video discs). Copyright © 2004 John Wiley & Sons, Ltd.
Deposition of Ti/C compositional gradient film onto superplastic Ti‐alloy by magnetron sputtering
Authors: Sonoda T. , Watazu A. , Kato K. , Yamada T. , Asahina T. 
Published: August 2004

AbstractDeposition of Ti/C compositional gradient film onto superplastic titanium‐based alloy such as Ti6Al4V or Ti4.5Al3V2Fe2Mo was performed by magnetron sputtering, in order to improve not only the biocompatibility and the abrasion resistance of the alloy but also the adhesion between the deposited film and the alloy substrate while preserving the high hardness of such ceramic coatings. The Ti/C compositional gradient films were deposited by co‐sputtering of two sputter cathodes which had pure titanium and titanium carbide targets, respectively, and their compositional gradient was realized by varying continuously the electric power supplied to each sputter cathode. Under visual observation, the obtained film appeared to be uniform and adhesive. According to AES in‐depth profiles, the carbon (C) concentration in the film gradually decreased in depth direction from the surface toward the substrate, confirming that Ti/C compositional gradient film had formed on the alloy substrate. On the basis of XRD, it was found that titanium carbide (TiC) and α‐titanium phases were formed in the films. Furthermore, the Vickers hardness of the films reached over HV = 1800. Therefore not only the biocompatibility and the abrasion resistance of the alloy but also the adhesion of the deposited hard coatings were expected to be improved by this method. Copyright © 2004 John Wiley & Sons, Ltd.
Surface characterization of titanium nitride composite coatings fabricated by reactive plasma spraying
Authors: Ingo G. M. , Kaciulis S. , Mezzi A. , Valente T. , Gusmano G. 
Published: August 2004

AbstractComposite Ti, TiN, TixNy coatings have been fabricated by reactive plasma spraying (RPS), starting from Ti alloy powders and using Ar/N2 plasma gas in a N2 atmosphere. Reactively sprayed coatings produced from SP700 (Ti4.5Al3V2Mo2Fe) and Ti6242 (Ti6Al2Sn4Zr2Mo) powders, deposited onto flat substrates of Ti6Al4V, have been investigated. XPS and SEM techniques have been used to determine the chemical composition and to characterize the interface between the coatings and substrate. The results obtained show a sharp interface between the coating and substrate in terms of composition profile. The presence of unmelted Ti particles as well as the formation of nitrides was observed. Copyright © 2004 John Wiley & Sons, Ltd.