bluuebunny/crossref_metadata_2025 huggingface dataset:
Where are we going? The fate and failings of contemporary spirituality
Authors: Caplan Mariana
Published: March 2006

This paper takes to task the dumbing‐down of spirituality in western culture. No stone is left unturned and no punches pulled in this self‐confessed rant at how spiritual truths and practices have been misunderstood, misinterpreted and misused – usually to remove any sense of discipline from spiritual practices and leaving them as sugary pills to comfort our egos rather than transform our lives. Healthy spirituality requires us to ‘walk the middle road’ without falling into the extremes or into the arms of extremists. Despite the critique, the author remains optimistic and ends on such a note. Although much of the article may at first seem cynical about the world of contemporary spirituality, the author is passionate about the possibility for our culture to grow out of spiritual childishness and adolescence and flourish into the maturity of spiritual adulthood. Copyright © 2004 Whurr Publishers Ltd.
Plasma functionalization, surface characterization and protein retention of multiple‐sized polymer beads
Authors: Manso M. , Rodriguez A. , Paul A. , Barrero J. , Rossi F.
Published: March 2006

The surfaces of several types of polymer beads used in solid‐phase extraction processes were modified with functional groups. Porous polystyrene (PS) macrospheres and polyvinylchloride (PVC) microspheres were plasma‐modified in a fluidized‐bed reactor by functionalization with allylamine (AlA) or acrylic acid (AcA). The surface compositions, as measured by XPS, showed the successful incorporation of the functional groups, and the numbers of these groups were assayed by derivatization onto model planar substrates. Furthermore, the influence on the surface Zeta potential of the beads was measured, which showed shifts of ±10 mV at physiological pH by the immobilized amino or carboxylic groups, respectively. A bovine serum albumin–fluorescein conjugate was used in a liquid chromatography system to evaluate the protein retention capacity. The results indicate higher protein retention on plasma‐treated beads with respect to the untreated materials, and on PS when compared to PVC. Particularly high retention is obtained with AlA functionalization at 100 W. Copyright © 2006 John Wiley & Sons, Ltd.
Transmission‐function correction for XPS spectrum imaging
Authors: Walton John , Fairley Neal
Published: March 2006

A procedure is described to characterise the performance of an imaging X‐ray photoelectron spectroscopy (XPS) instrument and to determine the intensity/energy response function at each pixel in an image, to provide traceable quantification and chemical‐state information from spectrum image data sets. Copyright © 2006 John Wiley & Sons, Ltd.
XPS depth profiling of oxide scales of stainless steels formed in high‐temperature aqueous conditions
Authors: Ignatova V. A. , Van Dyck St , Grötzschel R. , Möller W.
Published: March 2006

In this work, we studied the oxide scales of AISI 304 and AISI 316 stainless steels formed under high‐temperature aqueous conditions using X‐ray photoelectron spectroscopy (XPS) together with sputter depth profiling. Two samples of SS 304 and 316 were prepared by exposing them to water at 300 °C containing 100 ppm boric acid and 7 ppm lithium hydroxide in an autoclave.

In the case of sputtering with 3 keV argon ions, the elemental distribution as a function of the sputtering time was obtained. The formation of two oxide layers was observed—one mainly iron‐based on top, and a second at a greater depth, consisting mainly of chromium‐iron oxides. The depth scale of the profiles was calibrated by measuring the oxygen profile using Rutherford backscattering spectroscopy (RBS). On the basis of the distribution of the three oxidised alloying constituents (Fe, Cr, Ni) with respect to depth and elemental state, a relative increase of Fe2+ at the surface was found, while the chromium was depleted at the surface and Cr3+ tended to increase at the oxide/substrate interface. In order to estimate possible ion‐beam‐induced effects due to the ion sputtering, the profiles were compared to the computer‐simulated ones obtained by a dynamic TRIM computer code. The simulations included only collisional effects during the sputtering process. Copyright © 2006 John Wiley & Sons, Ltd.
Angular‐resolved elastic peak electron spectroscopy: experiment and Monte Carlo calculations
Authors: Zemek J. , Jiricek P. , Werner W. S. M. , Lesiak B. , Jablonski A.
Published: March 2006

Elastic peak electron spectroscopy (EPES) is widely applied for determining the inelastic mean free path (IMFP) of electrons, which is of crucial importance for quantitative electron spectroscopy. For this reason, it is highly desirable to verify the reliability of the EPES method for a variety of elements and different experimental geometries. In the present work, elastically backscattered electrons from Au, Ag, Cu, Fe and Si were measured at different experimental geometries (fixed incidence angle along the surface normal and various emission angles) for selected electron energies: 200, 500 and 1000 eV. The experimental angular distributions of elastically backscattered electrons were compared to the Monte Carlo (MC) calculations by the conventional and the reverse simulations.

Agreement between the results of conventional, reverse MC calculations and the experimental values of electron backscattering intensity was obtained. Application of the procedure for the surface‐excitation corrections resulted in better agreement between the simulated and the experimental data. Larger values of deviation were observed for grazing emission angles, indicating inaccuracy of the correcting procedure and the values of the material parameter, independent of the electron energy and the geometry of measurement. Copyright © 2006 John Wiley & Sons, Ltd.
A study of the tribological behavior of carbon‐nanotube‐reinforced ultrahigh molecular weight polyethylene composites
Authors: Wei Z. , Zhao Ya‐Pu , Ruan S. L. , Gao P. , Yu T. X.
Published: March 2006

The tribological properties of the high‐strength and high‐modulus ultrahigh molecular weight polyethylene (UHMWPE) film and the UHMWPE composites reinforced by multiwalled carbon nanotubes (MWCNT/UHMWPE) were investigated using a nanoindenter and atomic force microscope (AFM). The MWCNT/UHMWPE composites films exhibited not only high wear resistance but also a low friction coefficient compared to the pure UHMWPE films. We attribute the high wear resistance to the formation of the new microstructure in the composites due to the addition of MWCNTs. Copyright © 2006 John Wiley & Sons, Ltd.
Metastable impact electron emission microscopy: principles and applications
Authors: Lilienkamp G. , Suchorski Y.
Published: March 2006

Metastable impact electron emission microscopy (MIEEM) provides a mesoscopic visualization of surfaces by electrons emitted owing to metastable He*‐atom (23S) impacts and a spectroscopic contrast by an imaging energy filter. Since the metastable He* atoms excite the outermost surface electrons solely, a high surface sensitivity is achieved. The MIEEM imaging mode was realized by the combination of the He* source with the spectroscopic low energy electron microscope (SpecLEEM), thus allowing a reliable tracing of spatiotemporal surface processes within the field of view of ca 50 µm diameter. A few examples of MIEEM‐applications are presented: a study of the chemical composition of insulating islands appearing on lanthanum‐doped SrTiO3(100) surfaces as well as the first successful employment of MIEEM for the in situ imaging of surface reactions. Copyright © 2006 John Wiley & Sons, Ltd.
Electrochemically pretreated Bi2Pt2−yIryO7 pyrochlores—an X‐ray photoelectron spectroscopy study
Authors: Foelske A. , Steiger B. , Beck N. K. , Kötz R. , Scherer G. G. , Wokaun A.
Published: March 2006

Electrochemically pretreated Bi2Pt2−yIryO7 pyrochlores exhibit oxygen reduction activity and methanol tolerance and therefore are potential candidates for catalysts in fuel cells. In order to investigate the catalytically active surface for oxygen reduction, in this study, XPS measurements obtained from Bi2Pt2−yIryO7 pyrochlores in synthesized state and after electrochemical treatment in 0.5 M H2SO4 solution are presented.

The XP‐spectra of the Bi2Pt2−yIryO7 powders reveal some interesting features concerning core‐level shifts that are attributed to the electronic properties of these materials.

The catalytically active surface for oxygen reduction consists of a mixture of Pt0/Pt4+, Bi0/Bi3+ and Ir4+. Pt is enriched at the surface during activation. Sputter depth profiling provides evidence that metallic Pt0, which is supposed to serve the catalytic active sites, is present in the bulk material. Copyright © 2006 John Wiley & Sons, Ltd.
Analysis of a B4C/Mo/Si multilayer interferential mirror by SIMS: influence of the sputtering ion
Authors: Maury H. , Holliger P. , Farès B. , Gautier J. , Roulliay M. , Bridou F. , Delmotte F. , Ravet M.‐F. , André J.‐M. , Jonnard P.
Published: March 2006

We present the analysis of a B4C/Mo/Si multilayer interferential mirror (MIM) by secondary ion mass spectrometry (SIMS). The sample is prepared by magnetron cathodic sputtering and consists of a succession of 20 B4C (4.0 nm)/Mo (2.2 nm)/Si (12.0 nm) tri‐layers deposited on a silicon substrate. Two types of ions have been used for bombardment: Cs+ at an impact energy of 2 keV and O2+ at 0.5 keV. An artefact is clearly observed on the BCs+ profile which presents two maxima and a pronounced minimum at the maximum of the C profile, while the B profile obtained upon oxygen sputtering has its maximum in coincidence with that of the C profile. It is clearly seen under Cs and O sputtering that the B4‐on‐Mo and Si‐on‐B4C interfaces are more abrupt than the Mo‐on‐Si interfaces, evidencing the role of the boron carbide layer as a diffusion barrier. It is also observed that the B4C layers are inhomogeneous, some boron being present in excess with respect to C at the B4C‐on‐Mo and Si‐on‐B4C interfaces. These results evidence the importance of the interaction between the primary ions and some elements (boron in our case) present in the samples. Copyright © 2006 John Wiley & Sons, Ltd.
High‐energy X‐ray photoelectron spectroscopy with new monochromatised Cu Kα1 X‐rays; characteristics, capabilities and limitations
Authors: Moslemzadeh N. , Beamson G. , Haines S. R. , Tsakiropoulos P. , Watts J. F. , Weightman P.
Published: March 2006

High‐energy X‐ray photoelectron spectroscopy is a valuable technique for the study of the electronic and chemical states of materials. Here we present the specification, capabilities and restrictions of a recently built Cu Kα1 X‐ray source (hν = 8047.8 eV) and discuss a range of potential applications. Preliminary results from a study of Ti metal and TiO2 powder are presented with emphasis on the Ti 1s intrinsic plasmon loss and the Auger‐parameter shift. Comparison with data obtained from conventional soft X‐ray photoelectron spectroscopy (hν = 1486.6 eV) demonstrates the advantage of the Cu Kα1 source. Copyright © 2006 John Wiley & Sons, Ltd.
Detection of DNA hybridization by a field‐effect transistor with covalently attached catcher molecules
Authors: Han Y. , Offenhäusser A. , Ingebrandt S.
Published: March 2006

Electronic DNA sensors based on field‐effect transistor (FET) arrays operating in liquid environments offer an alternative method for the detection of biomolecular binding events without the requirement to label the analyte molecules. In order to obtain reproducible signals from such sensors, the attachment of the probe molecules to the gate area of the transistor chips requires a well‐controlled supramolecular architecture. The FET chips used in this work are non‐metallized, 8‐channel transistor devices with micrometer dimensions of the gate structures, which are encapsulated to be dipped into an analyte solution. Two identical chips were functionalized with DNA catcher molecules of different sequences and read out in a differential measurement approach. In this article, we describe the details of the surface modification and covalent attachment of the catcher DNA. The surface modification was characterized by XPS, Fourier transform infrared spectroscopy (FT‐IR), fluorescence microscopy and imaging ellipsometry. Electrical FET recordings of the immobilization and hybridization of DNA molecules are presented. Copyright © 2006 John Wiley & Sons, Ltd.
Curing and electrical conductivity of conductive glues for die attach in microelectronics
Authors: Scandurra A. , Cavallaro A. , Pignataro S. , Tiziani R. , Gobbato L. , Cognetti C.
Published: March 2006

The curing process of silver‐filled glues can be traditionally monitored through thermomechanical measurements such as differential scanning calorimetry (DSC). This technique is useful for the control of the polymerization and other chemical reactions mainly involving the organic moiety of the glue. However, it is not useful to ascertain whether good electrical conduction paths are established between all the conductive filler particles as expected at the end of the curing process. In this paper, we propose a method for the control of the surface electrical conductivity of a commercial silver‐filled glue, based on the charging‐up phenomena occurring in ESCA spectroscopy. Copyright © 2006 John Wiley & Sons, Ltd.
Monte Carlo simulation study of electron interaction with solids and surfaces
Authors: Ding Z. J. , Salma K. , Li H. M. , Zhang Z. M. , Tokesi K. , Varga D. , Toth J. , Goto K. , Shimizu R.
Published: March 2006

A brief overview is given on several aspects of applications of the Monte Carlo (MC) simulation method to surface‐related electron spectroscopy and microscopy. For the MC modeling of electron interaction with solids, the electron inelastic scattering cross section is calculated by the use of bulk dielectric function with optical constants in a dielectric functional approach. This has enabled the systematic reproductions of the experimental energy distributions of backscattered electrons for a number of elemental materials. An improved calculation of backscattering factor for quantitative AES analysis has been performed on the basis of a new definition and by making use of the up‐to‐date relevant cross sections. The physical reason is given for the backscattering factor that can be less than unity for very low primary energies close to the ionization energy and/or for large incident angles. For the MC modeling of electron interaction with surfaces, the inelastic scattering of electrons moving in a surface region is treated in a self‐energy formalism. The model has enabled the evaluation of the surface excitation effect through the calculation of position‐dependent electron IMFP. A simulation of REELS spectra for Ag is compared with an experiment; a reasonable agreement found on the surface plasmon peak intensity normalized with elastic peak intensity thus verifies this modeling of electron interaction with surfaces. Finally, the MC simulation code has been extended to deal with complex sample geometries. By using basic building blocks to construct a complex geometry and the ray‐tracing technique for correction of electron flight‐step‐length sampling, the structured and/or inhomogeneous sample can be modeled with reasonable flexibility. Copyright © 2006 John Wiley & Sons, Ltd.
XPS and RBS characterizations of electrosynthesized polypyrrole films doped with a heteropolyanion, SiMo12O404−
Authors: Debiemme‐Chouvy Catherine , Bernard Marie‐Claude , Cachet Hubert , Deslouis Claude
Published: March 2006

In this paper, the electrosynthesis of polypyrrole (PPy) films doped with a Keggin‐type heteropolyanion, SiMo12O404−, is reported. The in situ electrochemical growth of the hybrid film was conducted using an electrochemical quartz crystal microbalance (EQCM) that allowed us to evaluate the doping level of the polymers, which were synthesized in galvanostatic mode. By combining EQCM with chemical analyses, such as X‐ray photoelectron spectroscopy and Rutherford backscattering spectroscopy, it was evidenced that the doping level of the polymer depends on the current imposed during the PPy film synthesis. Copyright © 2006 John Wiley & Sons, Ltd.
PECVD coatings: analysis of the interface with the metallic substrate
Authors: Angelini E. , Grassini S. , Rosalbino F. , Fracassi F. , Laera S. , Palumbo F.
Published: March 2006

Plasma enhanced chemical vapor deposition (PECVD) from silicon‐containing organic compounds, such as SiOx coatings, appears to be an attractive treatment technique for the surface modification of metals in order to increase their corrosion resistance. This study deals with the characterization of SiNx thin films, in comparison with SiOx coatings, deposited on steels and aluminum alloys in a capacitively coupled (CC) parallel‐plate reactor and in an inductively coupled (IC) reactor. The nitride‐like coatings have been deposited in plasma fed with bis(dimethylamino)dimethylsilane (BIS) and Ar on as‐received substrates and after a plasma treatment performed in oxygen or hydrogen plasmas. SiOx coatings have been deposited starting from tetraethoxysilane (TEOS) in a mixture of Ar and O2. The substitution of oxygen by nitrogen can lead to higher tribological and mechanical properties, maintaining the insulating nature of the film. Surface and chemical characterization of the coatings have been carried out by means of X‐ray photoelectron spectroscopy (XPS) and Fourier transformed infrared spectroscopy (FTIR). The protective effectiveness of PECVD coatings has been assessed by electrochemical impedance spectroscopy (EIS) and may be related to their barrier effect against the diffusion of water and gaseous aggressive agents from the environment toward the metal surface. Plasma pretreatments play an important role in determining the barrier properties of the film by reducing its defectiveness and enhancing its adhesion to the substrate. Copyright © 2006 John Wiley & Sons, Ltd.
Straggling of fast electrons
Authors: Chaoui Zine‐El‐Abidine , Bichsel Hans
Published: March 2006

The energy losses of fast electrons vary because of the stochastic nature of the interactions. In order to describe these processes and calculate the spectra of the total energy loss (straggling spectra), Monte Carlo simulations of fast electrons traversing a thin silicon absorber have been used. The distribution functions needed are described by the electronic energy losses in single collision calculated by Bichsel. Comparison between straggling spectra calculated on the basis of the single collision spectrum and that from its first moment (very often ‘stopping power’ in the literature), shows that the latter, the so‐called ‘Continuous Slowing Down Approximation (CSDA),’ is a poor approximation in its description of the individual energy deposition. Copyright © 2006 John Wiley & Sons, Ltd.
Electron irradiated sodium–potassium–aluminium silicate glass surfaces investigated by XPS
Authors: Lesiak B. , Zemek J. , Gedeon O. , Jóźwik A.
Published: March 2006

Alkali‐aluminium silicate glasses are interesting due to their potential industrial applications. The most commonly applied methods for surface characterisation employ electron beam techniques operating with the electron beam affecting the atoms of solids and modifying glass surfaces.

In the present work, the effect of the electron beam on the surface of sodium–potassium–aluminium silicate glass is investigated. The atomic composition, structural changes and chemical state of atoms are studied by qualitative and quantitative photoelectron spectroscopy (XPS) and the line shape analysis using the pattern recognition (PR) method called the fuzzy k‐nearest neighbour (fkNN) rule. These methods proved to be applicable for complex glasses. Copyright © 2006 John Wiley & Sons, Ltd.
Characterization of F+‐irradiated graphite surfaces using photon‐stimulated desorption spectroscopy
Authors: Sekiguchi Tetsuhiro , Baba Yuji , Shimoyama Iwao , Nath Krishna G.
Published: March 2006

We investigated nature of the orientation in the topmost layers of F+‐irradiated graphite using polarization‐dependent near‐edge X‐ray absorption fine structure (NEXAFS) spectroscopy, incorporating partial electron‐yield (PEY) detection and photon‐stimulated ion desorption (PSID) techniques. The fluorine K‐edge NEXAFS spectra conducted in PEY mode showed no significant dependence on polarization angles. In contrast, NEXAFS spectra recorded in F+ ion yield mode showed enhanced yields at a feature of ∼689.4 eV, assigned as a σ*(CF) state relevant to CF sites: furthermore, the yields depended on polarization angles. The F+ ion yields at the feature are larger in normal incidence than in grazing incidence, suggesting that the CF bonds prefer a relatively downward tilt at the topmost layer, while being randomly directed at deeper regions. We conclude that the difference in the orientation structures between the surface and the bulk is reflected in the NEXAFS spectra recorded in the two different detection modes. It was also found that H+‐ and F2+‐PSID NEXAFS spectra are helpful in understanding the desorption mechanisms, and thus in analysing NEXAFS data. Copyright © 2006 John Wiley & Sons, Ltd.
XPS and SIMS study of aluminium native oxide modifications induced by Q‐switched Nd:YAG laser treatment
Authors: Barnier V. , Heintz O. , Roberts D. E. , Oltra R. , Costil S.
Published: March 2006

During laser cleaning of aluminium in ambient atmosphere, modifications of the metal surface can be induced by transient thermal effects. This work aims to characterize the modification of the aluminium oxide layer on pure aluminium for a wide range of power per area using a Q‐switched Nd:YAG (1064 nm) laser with two pulse durations, 10 and 180 ns. Experiments were carried out with single laser shots in ambient air at fluences (e.g. energy per area) below the ablation regime.

For 10‐ns pulses with fluences between 0.7 and 1.7 J/cm2, X‐ray photoelectron spectroscopy (XPS) and secondary ion mass spectroscopy (SIMS) revealed thermal oxidation with an increase of the oxide‐layer thickness for 0.7–1.3 J/cm2. Above a threshold at about 1.3 J/cm2 the oxide thickness decreased. The Mixing Roughness Model was used for the SIMS depth profile.

For 180‐ns pulses with fluences between 2.1 and 4.3 J/cm2, and therefore much lower power per area than with the 10 ns pulses, XPS showed a variation of surface composition with a different behaviour for 2.1–2.9 J/cm2 compared to 3.1–4.3 J/cm2. However, no significant changes of the average thickness of the oxide layer were found. Copyright © 2006 John Wiley & Sons, Ltd.
Shell layers of Ostrea edulis as an environmental indicator of TBT pollution: the contribution of surface techniques
Authors: Medaković Davorin , Traverso Pierluigi , Bottino Carlo , Popović Stanko
Published: March 2006

X‐ray powder diffraction (XRD) was used to study the mineral composition of the shells and shell layers of the European flat oyster Ostrea edulis (Linnaeus) collected at two localities in the East Adriatic Sea of the coast of Croatia. The variations of the shell element chemistry between two different shell layers were determined by X‐ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) with an energy dispersive X‐Ray (EDX) microprobe. XRD showed that the dominant component of the outer prismatic foliated shell layers was calcite with traces of aragonite and halite. The newly formed chambers of the inner nacreous shell layers were mainly built of magnesium calcite. Chemical element analysis given by XPS and SEM confirmed that besides carbonates other minor elements could be incorporated in the oyster shells. Silicon was present from 0.1 to almost 1.5 atomic percentage (at.%) in the outer shell layers, whereas its amount was lower and difficult to quantify in the inner shell layers. On the contrary, tin was detected only in the chambers of the newly formed inner nacreous layers, in a concentration that could be estimated, according to both XPS and SEM, to be of the order of 0.1–0.2 at.%. In the chambers of the oyster shells, tin is environmentally induced. A possible formation mechanism and specific ecological factors that could influence the precipitation of tin in the different shell layers of Copyright © 2006 John Wiley & Sons, Ltd.
Surface characterization of the Gram‐positive bacteria Bacillus subtilis‐an XPS study
Authors: Leone Laura , Loring John , Sjöberg Staffan , Persson Per , Shchukarev Andrei
Published: March 2006

Interactions at the bacteria‐solid interface in aquatic environments are of crucial importance in biofilm formation processes. The characterization of microbial surfaces properties is therefore a very important step for the understanding of these interactions. In this study, XPS spectra of Bacillus subtilis wet pastes centrifuged from suspensions over a span of pH values were recorded using a fast‐freezing procedure. The chemical composition of the bacterial surface was elucidated and the presence of surface sites containing carboxylate, phosphate and amine functional groups was established. It was possible to distinguish between charged and uncharged amine sites on the surface and follow their deprotonation reactions as a function of pH. It is suggested that increased metabolic activity around the physiological pH results in the excretion of proteins and/or peptides which are possibly related to the production of extracellular polymeric substances (EPS). Copyright © 2006 John Wiley & Sons, Ltd.
Interdiffusion in microstructurally different Si/Al multilayered structures
Authors: Wang J. Y. , He D. , Zalar A. , Mittemeijer E. J.
Published: March 2006

Two types of a‐Si/c‐Al multilayers were prepared by magnetron sputter deposition under different sputtering conditions. X‐ray diffraction (XRD) and transmission electron microscopy (TEM) techniques were used to analyse the microstructures of the as‐deposited multilayers. The multilayers showed different degrees of interface roughness. The c‐Al sublayers of the multilayers exhibited different levels of macrostress and microstrain and were of different grain size (corresponding to the sublayer thickness). Interdiffusion coefficients were determined by Auger electron spectroscopic (AES) depth profiling. The results indicated that the initial stage of diffusion annealing involved diffusion of Si along grain boundaries in the Al sublayer. The data obtained for the interdiffusion coefficient were insensitive to the present differences in microstructure between the multilayeres investigated. Crystallization of Si took place if appreciable diffusion of Si along the Al grain boundaries had occurred. Copyright © 2006 John Wiley & Sons, Ltd.
Applications of scanning thermal microscopy in the analysis of the geometry of patterned structures
Authors: Klapetek Petr , Ohlídal Ivan , Buršík Jiří
Published: March 2006

In this article, the results of the scanning thermal microscopy (SThM) analysis of artificial structures such as microchip surfaces and solar cell contacts are presented. It is shown that in the absence of surface roughness the SThM can be used to obtain reliable material contrast images. However, roughness and other topographical features can influence the thermal data in a strong way. It is illustrated that this effect can be partially removed by using the neural network approach for modelling the thermal signal using the topography data. The illustration of this approach is presented in the analysis of the geometry of the examples selected in this article. Copyright © 2006 John Wiley & Sons, Ltd.
Nanoprocessing and evaluation of carbon and boron nitride nanoperiod multilayer films by lateral force modulation method
Authors: Miyake Shojiro , Hashizume Tsuyoshi , Wakatsuki Yukihiko
Published: March 2006

Carbon and boron nitride nanoperiod (C/BN)n multilayer films were deposited by bias radio frequency (RF) sputtering. It was proposed that using the lateral modulation friction force microscopy technique (LM‐FFM), a nanoprocessing removal by mechanical action was performed on the nanoperiod (C/BN)n multilayered films with electroconductive diamond tips. It was found that the amplitude and phase of the tip cantilever torsion due to friction force between the tip and the sample surface varied with an increase in loading force when the film was processed with vibration. Since the amplitude variation obtained after this processing was correlated with the frictional force of each layer, the result that the amplitude varied with an increase in the processing depth indicated the nanostructure of this multilayer film. This suggested that the LM‐FFM method could perform nanoprocessing and microstructure analysis. As a result, the structure of the 2‐nm‐period multilayer film was experimentally confirmed to consist of the C‐layer, the interface, and the BN layer by this method. Copyright © 2006 John Wiley & Sons, Ltd.
Growth of TiO2 nanocrystals in the presence of alkylpyridinium salts: the interplay between hydrophobic and hydrophilic interactions
Authors: Ardizzone S. , Bianchi C. L. , Cappelletti G.
Published: March 2006

TiO2 nanoparticles were prepared by combining a sol–gel precipitation with growth steps performed in the presence of cationic surfactants, dodecylpyridinium chlorides (DPC), and cetylpyridinium chlorides (CPC). Solutions at concentrations pertaining to the existence of either surfactant monomers or aggregates (micelles) were employed. XPS analyses were performed both on the surfactant salts and on the aged, dried precursors to study the surfactant films adsorbed onto the oxide. The crystal structures of the calcined samples and the phase composition were examined by X‐ray diffraction. The role played by the presence of the surfactant in affecting the physicochemical properties of the powders is discussed. Copyright © 2006 John Wiley & Sons, Ltd.
Investigation of passive films grown on biocompatible Ti‐50Zr and Ti‐13Zr‐13Nb alloys by XPS
Authors: Oliveira N. T. C. , Biaggio S. R. , Nascente P. A. P. , Rocha‐Filho R. C. , Bocchi N.
Published: March 2006

In this work, XPS investigations on the composition of anodic films electrochemically grown on heat‐treated Ti‐50Zr (at.%) and Ti‐13Zr‐13Nb (wt.%) alloys in 0.15 mol dm−3 Na2SO4 at room temperature are reported. The XPS analyses on anodic films of different thicknesses revealed for both alloys a gradual enrichment of the oxide film in Ti as the film thickness was increased. For the thickest oxide films, this Ti enrichment in the oxide was about 8% for the Ti‐13Nb‐13Zr alloy and about 9% for the Ti‐50Zr alloy, when compared with the nominal values for both alloys determined by inductively coupled plasma‐atomic emission spectroscopy (ICP‐AES). Copyright © 2006 John Wiley & Sons, Ltd.
ToF‐SIMS analysis of organic impurities in UPW
Authors: Kobayashi Junji , Owari Masanori
Published: March 2006

We have investigated adsorption of organic impurities in ultrapure water (UPW) on hydrophilic silicon wafer surface. The primary and tertiary amine molecules used as model compounds of organic impurities were adsorbed on the clean wafer surface during soaking in UPW. It was found that adsorbed quantities of relatively large tertiary amines among water‐soluble amines, such as (C3H7)3N and (C4H9)3N, were higher at relatively short soak time (two h in this experiment) than at longer one (24 h). Time‐of‐flight secondary‐ion mass spectrometry (ToF‐SIMS) is a very powerful tool for identification of trace organic contamination on wafer surface after UPW rinse from the studies of adsorption of the molecules present in UPW. Copyright © 2006 John Wiley & Sons, Ltd.
Angle‐resolved XPS: a critical evaluation for various applications
Authors: Oswald S. , Zier M. , Reiche R. , Wetzig K.
Published: March 2006

Angle‐resolved X‐ray photoelectron spectroscopy (ARXPS) is widely accepted as a useful tool for nondestructive in‐depth analysis of near surface regions. In the present paper, it is shown for a variety of applications which kind of qualitative and quantitative information can be derived from ARXPS measurements in conjunction with appropriate mathematical modeling. The method is limited mainly by problems arising from contamination, roughness or preparation‐induced damage. Furthermore, especially for more complex surface structures, it must be considered that the information content of ARXPS is strongly limited and the calculations have to be supported by other knowledge. Copyright © 2006 John Wiley & Sons, Ltd.
Immobilization of GOD and HRP enzymes on nanostructured substrates
Authors: Curulli A. , Cusmà A. , Kaciulis S. , Padeletti G. , Pandolfi L. , Valentini F. , Viticoli M.
Published: March 2006

The study of the entrapment of glucose oxidase (GOD) and horseradish peroxidase (HRP) enzymes on different solid‐state substrates has been carried out. By using conventional methods, these enzymes have been immobilized on the following substrates: commercial Si wafers, thin films of nanostructured TiO2 and gold nanotubes grown on polycarbonate membranes. Surface chemical composition and morphology of the samples have been investigated by means of X‐ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). Peak‐fitting analysis of the main XPS signals permitted identification of the fingerprints of GOD and HRP enzymes and comparison of their entrapment on different substrates. The highest amount of attached enzymes was registered on the nanostructured TiO2 films prepared by using the sol–gel technique. Moreover, the surface impurities, remaining on the samples after the immobilization of the phosphate buffer solution, were identified, and their removability by sample washing in deionized water was demonstrated. Copyright © 2006 John Wiley & Sons, Ltd.
The initial oxidation of zirconium—oxide‐film microstructure and growth mechanism
Authors: Jeurgens L. P. H. , Lyapin A. , Mittemeijer E. J.
Published: March 2006

The initial stage of thermal oxidation of bare Zr within the temperature range of 373–773 K at a pO2 of 2 × 10−6 Pa was investigated by combined application of angle‐resolved XPS (AR‐XPS) and in situ spectroscopic ellipsometry (SE). A model description of the oxide‐film growth kinetics was achieved adopting coupled currents of cations and electrons within a surface‐charge field. The model could be fitted very well to the experimental data, thereby yielding profound knowledge of the relation between the oxidation mechanism and the developing oxide‐film microstructure. Copyright © 2006 John Wiley & Sons, Ltd.
Optical properties of thin iron oxide films on steel
Authors: Goossens V. , Wielant J. , Van Gils S. , Finsy R. , Terryn H.
Published: March 2006

Steel is used for many applications, yet little research has centred on the optical properties of steel and its oxides compared to low‐density materials such as aluminium and titanium.

In this paper, the optical properties of iron oxides on interstitial free steel substrates are studied. The oxide layers were thermally grown under an oxygen atmosphere at 250 °C. Two iron oxide types were present, i.e. α‐Fe2O3 (hematite) and Fe3O4 (magnetite). The optical constants of the oxide layer are determined by visual spectroscopic ellipsometry (VISSE). VISSE allows a fast and non‐destructive determination of both layer thickness and optical constants. An optical model was constructed to allow for the extraction of the layer thickness from the ellipsometric data. From this model, the total reflection, and therefore also the colour of the sample were calculated. The model is a good predictor of the system's colour, which proves that the colour originates from both interference and absorption effects. Copyright © 2006 John Wiley & Sons, Ltd.
Structural, chemical and magnetic characterization of iron nitride thin films
Authors: Prieto P. , Palomares F. J. , Gonzalez J. M. , Pérez‐Casero R. , Sanz J. M.
Published: March 2006

Iron nitride thin films were deposited on Si (100) substrates at 150 °C using a dual ion beam sputtering system. The structure, chemical composition and magnetic properties of the films were studied as a function of the deposition conditions. The bombardment with N2+ ions during the deposition of Fe by sputtering enabled control of the nitrogen content in the films and the formation of different iron nitride phases with different magnetic properties.

The chemical, electronic and structural characterization of the films were performed by Rutherford backscattering spectrometry (RBS), AES‐depth profiling, and X‐ray diffraction (XRD), whereas the magnetic behavior was studied using a vibrating sample magnetometer (VSM).

The results show that the magnetic moment of the Fe atoms decreases and the coercivity of the films increases almost linearly as the nitrogen content in the films increases up to the formation of ζ‐Fe2N, which is not magnetic. Copyright © 2006 John Wiley & Sons, Ltd.
Modeling the XPS Si 2p core‐level intensities of silicon nanocrystals for determination of oxide shell thickness
Authors: Renault O. , Marlier R. , Barrett N. T. , Martinez E. , Baron T. , Gely M. , De Salvo B.
Published: March 2006

We have developed a simplified model of the core and oxide shell XPS intensities of 5‐nm diameter Si nanocrystals for determining the shell thickness. The model is based on a cylindrical shape of the nanocrystals that allows the use of Himpsel's model for planar Si oxidation, and takes into account different escape depths for photoelectrons emitted by the core and the shell. The experimental core/shell intensity ratio is obtained from high‐resolution XPS spectra recorded with synchrotron radiation (photon energy 320 eV). The resulting calculated shell thickness is found to vary over the 0.74–1.32 nm range in a consistent way, according to the surface treatment performed on the nanocrystals. Copyright © 2006 John Wiley & Sons, Ltd.
Post‐chromatographic TOF‐SIMS identification of diterpenes
Authors: Oriňák Andrej , Oriňáková Renáta , Arlinghaus Heinrich F. , Vering Guido , Hellweg Sebastian
Published: March 2006

Mixture of two diterpenes was separated by thin layer chromatography (TLC) on different substrates and then analysed with time‐of‐flight secondary ions mass spectrometry (TOF‐SIMS). Abietic (AA) and gibberellic acids (GA) were separated on three different chromatographic thin layers: monolithic silica chromatographic ultra‐thin layer (A), aluminium backplate modified silica gel thin layer (B) and commercially available Raman spectrometric thin layer (C). GA is more polar and is stronger retained near the start of layer while AA moves with mobile phase front (ethanol–water, 40:60, v/v). Primary detection with UV lamp was possible only for AA. TOF‐SIMS macroscans of chromatographic thin layer surfaces have been collected for most intensive positive or negative charged ions. The most applicable TOF‐SIMS analytical signal response was obtained from analytes separated on monolithic silica and aluminium backplate modified thin layer surface. Thin layer produced for on‐line Raman spectroscopy is only partially suitable for TOF‐SIMS analysis and this substrate does not support construction of negative ions macroscans. The suitability of the substrates for post‐chromatographic TOF‐SIMS analysis was found in order: Raman spectroscopy thin layers < monolithic silica < and aluminium backplate modified surface—for negative ion macroscans. For positive‐ion macroscans formation, the order is as follows: Raman spectroscopy layer < aluminium backplate modified surface < and monolithic silica. The results obtained from these analyses should be applied in future coupling of TOF‐SIMS with microcolumn high‐performance liquid chromatography (µHPLC), online. TOF‐SIMS was chosen for its outstanding capabilities in molecular surface analysis and surface imaging, in particular, of mono‐, di‐, seskviterpenes. Copyright © 2006 John Wiley & Sons, Ltd.
Surface characteristics of 2‐(diethylamino) ethyl methacrylate–2‐(dimethylamino) ethyl methacrylate diblock copolymer determined by inverse gas chromatography
Authors: Topaloğlu Yazıcı D. , Aşkın A. , Bütün V.
Published: March 2006

The surface characterization of a 2‐(diethylamino) ethyl methacrylate–2‐(dimethylamino) ethyl methacrylate diblock copolymer [DEA‐DMA] was carried out using inverse gas chromatography (IGC). The adsorption thermodynamic parameters (the standard enthalpy (ΔHo), entropy (ΔSo), and free energy of adsorption (ΔGo)), the dispersive component of the surface energy ($\gamma_{S}^{d}$), and the acid–base character of the surface of the block copolymer were estimated using the retention time of different nonpolar and polar probes at infinite dilution region. This block copolymer showed convenient values of dispersive surface energy as compared to conventional polymers. The specific free energy of adsorption (ΔGsp), the specific enthalpy of adsorption (ΔHsp), and the specific entropy of adsorption (ΔSsp) of polar probes on diblock copolymer were determined. The values of the ΔHspwere correlated with both the donor and the modified acceptor numbers of the probes to quantify the acidic KA and the basic KD parameters of the block copolymer surface. The values obtained for the KA and KD parameters indicated a basic character for the surface of the DEA‐DMA diblock copolymer. Copyright © 2006 John Wiley & Sons, Ltd.
Angular distribution of electrons backscattered elastically from silver
Authors: Tőkési K. , Varga D.
Published: March 2006

The angular distributions of electrons backscattered elastically from a polycrystalline silver sample are studied theoretically. The simulation is based on the Monte Carlo technique where both the elastic and inelastic scattering events are taken into account. We analyzed the effect of multiple electron scattering to the spectra of elastically backscattered electrons. Copyright © 2006 John Wiley & Sons, Ltd.
A work function study of ultrathin alumina formation on Cu‐9%Al(111) surface
Authors: Song Weijie , Yoshitake Michiko
Published: March 2006

We studied work function changes during oxidation of Cu‐9%Al(111) surfaces at 900 and 670 K as a function of oxygen exposure in situ using ultraviolet photoelectron spectroscopy and Kelvin probe. The results showed that work function first decreased by 0.51 eV after 256 L O2 exposure at 900 K, and then remained unchanged upon further oxygen uptake. The formation of the interfacial dipole layer was the main factor that determined work function and XPS binding energy shifts of Al2O3 energy levels at 900 K. The changes of work function and contact potential difference for amorphous Al2O3 formation at 670 K were similar to their trends at 900 K. The oxide over‐layer structure showed little influence on the work function of the Al2O3/Cu‐9%Al(111) system. Copyright © 2006 John Wiley & Sons, Ltd.
Interactions of reactive polypyrrole‐coated polystyrene latex particles with gold nanoparticles and silanized glass
Authors: Yip Yann , Benabderrahmane Sihem , Zhicai Ma , Bousalem Smain , Mangeney Claire , Chehimi Mohamed M.
Published: March 2006

Polypyrrole‐coated polystyrene latex particles (400–1000 nm‐sized) bearing reactive amino, carboxylic acid and N‐succinimidyl ester groups (PS‐PPyNH2, PS‐PPyCOOH and PS‐PPyNSE, respectively) were prepared by the in situ copolymerization of pyrrole (Py) and the N‐functionalized pyrrole in the presence of PS particles.

The PS‐PPy spheres have a core/shell structure resulting in the formation of hollow particles after selective extraction of PS. The PS‐PPyNSE particles were immobilized at pH 7.4 onto various silanized glass plates. Surface coverage decreased in the order mercaptosilane > aminosilane ≫ methylsilane. The PS‐PPyCOOH was effective in forming 2D hexagonal assemblies onto aminated glass at pH 7 but not at pH 5. The PS‐PPyNH2 spheres can be decorated with citrate‐stabilized gold nanoparticles via electrostatic interactions and transformed into Au‐decorated hollow PPyNH2 particles after selective extraction of PS. Finally, gold nanoparticles immobilized onto an aminated glass plate could serve as a conversion layer for the massive attachment of PS‐PPyNH2, resulting in a very rough conductive overlayer. Copyright © 2006 John Wiley & Sons, Ltd.
Investigation of the interface manipulation in SiC(100) on Si(100) with isovalent impurities
Authors: Pezoldt J. , Morales F. M. , Zgheib Ch. , Förster Ch. , Stauden Th. , Ecke G. , Wang Ch. , Masri P.
Published: March 2006

SIMS and transmission electron microscopy studies revealed an improvement of the SiC/Si(100) heterostructure properties if isovalent atoms with larger atomic dimensions than Si and C were used to modify the interface. The Ge incorporation at the interface suppresses the outdiffusion of Si from the substrate to the surface of the growing SiC layer and, therefore, impedes surface and interface roughening as well as the formation of voids at the SiC/Si interface. SIMS measurements obtained revealed that Ge remains at SiC/Si interface independently of the predeposited amount on Si(100) substrates. Copyright © 2006 John Wiley & Sons, Ltd.
Pulsed r.f.‐glow‐discharge time‐of‐flight mass spectrometry for fast surface and interface analysis of conductive and non‐conductive materials
Authors: Hohl M. , Kanzari A. , Michler J. , Nelis T. , Fuhrer K. , Gonin M.
Published: March 2006

Glow discharge (GD) is a highly specialised source that especially meets the requirements for accuracy, simplicity and speed for content depth profiling and bulk analysis in both optical emission (OES) and mass spectrometry (MS). The pulsed radio frequency GD source has the potential for both elemental and molecular analysis of conductive and non‐conductive materials. To exploit the information delivered by pulsed radio frequency (r.f.)‐GD sources, fast sampling is required, and is available only through time‐of‐flight mass spectrometry (ToF‐MS). Compared to optical glow discharge (GD‐OES) instrumentation, a GD‐ToF‐MS system shows much simpler spectra, lower background signals and lower detection limits. The presented new r.f.‐GD‐ToF‐MS system is a successful combination of a commercial high‐end glow discharge instrument and an extremely fast and high‐resolution time‐of‐flight mass spectrometer. This new instrument was applied to analyse conductive and non‐conductive materials like anodic thin films. We could resolve 2‐nm Cr makers in aluminium oxide layers and measure trace elements in ultra thin titanium oxide films. Furthermore, we show the potential of the pulsed mode to separate analyte species from elements originating from residual gas. Copyright © 2006 John Wiley & Sons, Ltd.
Electroless deposition study of silver into porous silicon
Authors: Fortas G. , Sam S. , Gabouze N. , Guerbous L. , Belaroussi Y. , Manseri A.
Published: March 2006

In the present work, immersion plating method was used to deposit silver (Ag) into a porous silicon (PS) layer. The properties of the deposited layers as a function of the concentration of the solution and deposition time were investigated by X‐ray diffraction (XRD), scanning electron microscopy (SEM), secondary ion mass spectrometry (SIMS) and photoluminescence (PL). The results show that immersion plating is an efficient method to deposit Ag into the PS. It was found that the Ag diffusion in the porous layer reaches a depth of about 0.6 µm. Furthermore, the Ag grain sizes were highly dependent on the concentration of the solution and the deposition time. Finally, the luminescence measurements indicate an efficient PL of the sample with Ag deposit. In addition, compared to the PS luminescence spectrum, a red shift of the PL peak wavelength is observed. Copyright © 2006 John Wiley & Sons, Ltd.