bluuebunny/crossref_metadata_2025_split huggingface dataset:
XPS, SEM and EDX analysis of conditioning film deposition onto ureteral stents
Authors: Reid Gregor , Davidson Ross , Denstedt John D. 
Published: May 2005

AbstractUreteral stents are commonly used in urology to drain urine from the kidney. An important complication arises when bacteria or encrustations adhere to the surfaces, causing infection and/or blockage of urine flow. It was hypothesized that upon exposure to urine flow, host elements are deposited as a conditioning film onto the surface of the materials, changing their characteristics. This was studied by x‐ray photoelectron spectroscopy analysis of stents removed from stone‐forming patients and in a stent incubated in vitro with urine. In addition to nitrogen being adsorbed, there was evidence of additional carbon compounds bound to hydroxyl and carboxyl and on some stent surfaces calcium and phosphorus were detected. When a stent was incubated in vitro with urine, nitrogen adsorbed along with a new type of carbon compound bound to hydroxyl. Scanning electron microscopy showed the presence of extensive bacterial biofilms, even after antibiotic therapy, and the existence of tears, erosions or abrasions in the stent surfaces within 2 weeks of implantation. Energy‐dispersive x‐ray analysis confirmed the presence of calcium, magnesium phosphorus and carbonate apatite crystals. These findings have important clinical implications.
Auger electron spectroscopy studies of interdiffusion in electrodeposited amorphous NiP alloys
Authors: Bukaluk Antoni 
Published: May 2005

AbstractThe effect of annealing on the Auger electron depth profiles of electrodeposited amorphous Ni100‐yPy/Ni100‐xPx (15 < x < 32 at.%, y > x) thin film couples is studied at temperatures in the range 190–280 °C. Diffusion coefficients are evaluated by means of the Boltzmann–Matano method. The composition dependence of diffusion coefficients is explained by the role of free volumes in amorphous materials on interdiffusion.
Laser etching of silicon: Dopant desorption, diffusion and segregation during laser induced surface melting
Authors: Desmur A. , Ozenne J.‐B. , Bourguignon B. , Boulmer J. , Budin J.‐P. , Débarre D. , Aliouchouche A. 
Published: May 2005

AbstractThe laser induced redistribution and desorption of dopant atoms (B, As, Sb) is measured in presence and in absence of chlorine at the surface. We define a desorption efficacy which is found to depend strongly on the dopant atom, increasing from boron to arsenic and to antimony. The implications for etching, doping and annealing experiments are discussed.
An XPS valence band study of alkane chains secondary structure
Authors: Riga J. , Delhalle J. , Deleuze M. , Pireaux J. J. , Verbist J. J. 
Published: May 2005

AbstractValence XPS studies of well oriented polyethylene mats, deposited on a gold substrate, provide direct evidence of the existence of the fold structure at the sample surface and confirm earlier suggestions that conformation is directly fingerprinted in that energy region of the spectra. These results also provide new insight into the origin of the valence XPS spectra differences, so far unexplained, of n‐tridecane recorded in gas and solid phase.
Surface compositional changes of InP due to krypton ion bombardment
Authors: Malherbe J. B. , van der Berg N. G. 
Published: May 2005

AbstractSputtering of the (110) and (100) surfaces of InP by Kr+ ions resulted in a preferential loss of the phosphorus species leaving an In‐enriched surface. The equilibrium Kr+‐sputtered surface composition of InP was determined by means of Auger electron spectroscopy. The sputtered surface composition ratio was independent of crystal orientation and ion energy (between 0.5 and 5 keV). Owing to a lack of other experimental krypton sputtering data, the experimentally obtained surface composition ratios were compared to the Sigmund theory for preferential sputtering in the linear cascade regime. A comparison with the Sigmund spike model showed the absence of spike effects in this krypton ion energy regime. A reasonable agreement was obtained between the experimental results and the Sigmund predictions. There was a correlation between the angle of incidence of the bombarding Kr+ ions and the final surface composition: The preferential sputtering effect became less with increasing angle of incidence θi (measured from the surface normal). The results show that the ratio of the phosphorus to indium compositions, namely X/X ∝ (cos θi)−a with a ≃ 0.24, and where θi is the angle of incidence of the ion beam with respect to the sample normal. This result is explained in terms of a model using the angle dependence of the sputtering yield of the constituent elements.
Small‐area XPS and XAES study of the iron ore smelting process
Authors: Ingo G. M. , Mazzoni S. , Bultrini G. , Fontana S. , Padeletti G. , Chiozzini G. , Scoppio L. 
Published: May 2005

AbstractThe iron ore deposit of Kerry (north‐western Syria) has been sampled; by means of the combined use of small‐area x‐ray photoelectron spectroscopy (SA‐XPS), small‐area x‐ray induced Auger electron spectroscopy (SA‐XAES), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), differential thermal analysis (DTA) and thermal gravimetric analysis (TGA), the smelting process of the most iron‐rich ore has been studied under a CO atmosphere up to 1570 K. Attention has been focused on the chemical aspects involvéd during the reduction of the iron ore and on the chemical composition of the non‐metallic compounds, i.e. the slags, that result from the smelting process. Furthermore, this information has been compared with that obtained from early iron metallurgy slags and artefacts found in north‐western Syria in order to locate the geographical source of the iron ore exploited during the early Iron Age in this region.
Chemical information from Auger data using factor analysis: Some examples
Authors: Chemelli C. 
Published: May 2005

AbstractExtracting chemical information from Auger data is an arduous task, particularly when signals result from the contribution of several components. The numerical method known as factor analysis (FA) can be powerful in enhancing the presence of poorly visible lineshape contributions and in quantification problems. Nevertheless FA is still little employed in Auger data handling.This paper deals with applications of Auger data factor analysis to the study of solid state reaction at oxide–oxide and metal–silicon interfaces.Attention is focused on the details of data pre‐processing, observation of abstract solutions and physical significance of results.
Simulation of insulator charging by a narrow electron beam
Authors: Vicario E. , Rosenberg N. , Renoud R. 
Published: May 2005

AbstractWe are dealing with the problem of the charge distribution within an insulator (present application: SiO2) which is bombarded by a narrow electron beam. The electron trajectories within the sample are simulated via a single diffusion Monte‐Carlo method. A mathematical model is proposed for the potential and the charge density. The development of an electric field, a potential and the broadening of the incident beam are taken into account. These two last distributions appear to have a prominent effect. It is shown that the charge distribution tends to a double layer; the shape and thickness of positive and negative distributions are given.
XPS analysis of lithium intercalation in thin films of molybdenum oxysulphides
Authors: Benoist L. , Gonbeau D. , Pfister‐Guillouzo G. , Schmidt E. , Meunier G. , Levasseur A. 
Published: May 2005

AbstractThin films of molybdenum oxysulphides which could be used as positive electrode materials in microbatteries were analysed by XPS. The results have shown the existence of a new environment for molybdenum with S22− pairs, S2− and O2− ions. The evolution of these thin films MoOySz at different stages of their cycle in experimental generators has also been studied; the main elements involved in the redox processes have been characterized: molybdenum atoms with +6 formal oxidation number and disulphide pairs S22−.
Surface modification of PET films with RF plasma and adhesion of in situ evaporated Al on PET
Authors: Le Quoc Toan , Pireaux J. J. , Verbist J. J. 
Published: May 2005

AbstractPET (Polyethylene terephthalate) films were modified with two different plasmas, nitrogen and oxygen, as a function of treatment times and RF powers. Firstly, the chemical composition of the plasma‐modified PET films was investigated by XPS. In the case of nitrogen plasma, the formation of amine, imine and amide groups is detected. A slight diffusion of nitrogen‐containing species into the PET bulk is also observed by angle‐resolved XPS measurements. The appearance of alcohol, carbonyl and carboxyl functions is observed in the case of oxygen plasma treatment. After thermal deposition of an aluminium film, peel tests reveal that the Al/PET adhesion increases as follows: untreated < nitrogen plasma < oxygen plasma treatment.Secondly, after sevderal successive depositions of thermally evaporated Al on oxygen plasma treated PET film, XPS was used to study the chemistry at the interface. The XPS results reveal that the additional reactive sites created on the PET surface by the treatment explain the significant improvement in Al/PET adhesion observed for plasma‐modified samples.
Interface analysis of ceramic matrix composites by XPS, AES, SEM and XRD
Authors: Contarini S. , Giunta G. , Loreti S. , Nistico N. , Lambers E. , Holloway P. H. 
Published: May 2005

AbstractThe analysis of interfaces between silicon carbide or carbon fibres and a glassy sol‐gel derived SiO2 matrix in ceramic matrix composites (CMC) is presented. The x‐ray photoelectron spectra (XPS) indicate a differential charging effect on all samples, potentially related to the adhesion strength at the interface. By Auger electron spectroscopy (AES) a silicon oxide layer is found on the surface of SiC fibres while no oxygen is detected on the C fibres. Effects of ageing in air or nitrogen at high temperature for 100 h were also studied. While no crystalline phases are present in the x‐ray diffraction (XRD) patters of sintered samples before ageing, different amounts of an SiO2 (low cristobalite) phase appear on heating at 1200 °C in air or in N2. SEM images indicate concomitant porosity upon ageing. Auger point analysis on the longitudinal fracture surface of the SiC composites aged in air shows a thicker oxide layer, while SiC composites aged in N2 atmosphere show no relevant oxidation but presence of carbon on the fibre surface. The carbon layer at the interfaces correlates with fibre pull‐out observed by SEM on SiC/SiO2 specimens heated in N2. The competition between physical (temperature‐induced) and chemical (gas‐induced) modifications observed by combined surface and bulk techniques is discussed.
XPS and SEM studies of Ca‐ and Ni‐substituted LaCrO3 after quenching from reducing and oxidizing atmospheres at 800 °C
Authors: Glenne Rita , Horst Jens Anton , Jørgensen Sissel , Norby Truls , Seiersten Marion 
Published: May 2005

AbstractSintered and polished samples of La1−xCaxCrO3(x = 0.0, 0.1, 0,3, 0.5) and La1−xCaxCr1−yNiyO3(x = 0.3, y = 0.05) were annealed and quenched under reducing or oxidizing conditions at 800 °C and analysed with XPS and SEM. After annealing in H2 + H2O the surfaces of the samples with x = 0.3 and x = 0.5 were enriched in Ca in a 5 nm deep zone. Cr was not enriched and was present in the +3 state. Annealing in O2 + H2O gave Ca enrichment and crystalline outgrowths, increasing with increasing Ca contents. The Cr in the surface was in the +3 and +6 states, and the amount of Cr6+ increased with increasing Ca contents. These observations are assigned to precipitation of CaCrO4 and possibly other phases. The Ni‐doped sample exhibited less grain growth during sintering and less surface recrystallization in oxidizing atmospheres than the corresponding sample without Ni.
An interfacial study of a sigma fibre/Ti‐6Al‐4V composite using scanning Auger/EDX microscopy
Authors: Baker M. A. , Upadhyaya D. 
Published: May 2005

AbstractThe interfacial region of a Sigma fibre/Ti‐6Al‐4V composite has been studied by Auger/EDX microscopy. The SiC fibre has a duplex coating consisting of an inner layer of C and outer TiBx layer. Point analyses, line scans and images were acquired from the fibre/matrix interface region for a specimen taper sectioned at 10° to the fibre axis and a sample fractured in situ along the fibre length. Fracture of the composite reveals the presence of a brittle B rich oxide layer probably of the form TixByO at the boride coating/matrix interface. The fracture path occurs either through this oxide or the graphitic carbon layer. C is shown to have diffused through the entire boride coating. B diffuses from the TiBx layer into the matrix, forming TiB at the interface. The presence of excess boron in the coating and the strong affinity of B for O are proposed as the main driving forces for oxide formation at the TiBx/matrix interface.
Ellipsometric investigation of single crystalline CzSi subjected to hydrostatic pressure
Authors: Kamińska Anna M. , Misiuk Andrzej , Wolf Jürgen 
Published: May 2005

AbstractThe application of ellipsometry to study the SiOx/Si system subjected to hydrostatic pressures up to 1.8 GPa at temperatures up to 1280 °C is described. The theoretical model of defects as the spherical disturbances of material has been assumed. The ellipsometric parameters have been analysed as a function of defects size and density and compared with data obtained by etching and x‐ray methods. The applicability of ellipsometry for near‐surface defect structure analysis has been discussed.
XPS‐investigation of titanium modified MFI‐type zeolites
Authors: Grohmann I. , Pilz W. , Walther G. , Kosslick H. , Tuan V. A. 
Published: May 2005

AbstractThe chemical bonding of titanium in MFI‐type zeolites (Ti‐silicalite) has been investigated using x‐ray photoelectron spectroscopy (XPS). Different titanium silicalites as well as pure titania (anatase) have been analysed. We have found a distinctively higher binding energy of the Ti 2p photoelectrons in Ti‐silicalite than in titania‐ or anatase‐containing silicalite. Ti has the same oxidation state in all solids under study. We attribute the difference in binding energy to different oxygen coordinations of the titanium in the framework of Ti‐silicalite (tetrahedral) and anatase (octahedral). This suggestion is supported by XPS‐studies of TiO2SiO2 glasses and TiO2SiO2 mixed oxides where a similar shift was found. Additional Raman‐spectroscopy investigations of the samples indicate the existence of tetrahedrally coordinated titanium by the appearance of a characteristic band at ∼ 965 cm−1. Non‐framework TiO2 species containing octahedrally coordinated titanium could also be distinguished by XPS. Further Ti incorporation is indicated by the expansion of the unit cell which is related to the Ti 2p intensity for the framework titanium.
Study of the bulk and surface acidity of protonated Y zeolites by TPD and XPS
Authors: Guimon C. , Boreave A. , Pfister‐Guillouzo G. 
Published: May 2005

AbstractThe combined use of temperature programmed desorption (TPD) of nitrogened bases (ammonia, pyridine) and x‐ray photoelectron spectroscopy (XPS) was applied to the study of acidity of HY zeolites with different molar Si/Al ratios (∼ 2.7, 5.8, 24).N1s binding energies of probe molecules showed two types of sites (Brönsted and Lewis) whose relative proportions varied with pretreatment and desorption temperatures, and a dissociative adsorption of NH3 for dehydroxylated zeolites.The TPD curves and the XPS quantitative analyses of probe molecule concentration in Zeolites allowed the determination of acid sites distribution in term of strength for the real surface of crystals and for a sub‐surface partially freed of extra‐framework species that cover it. These data showed that the acid sites located in sodalite units are mostly strong and Brönsted type sites.
In search of the ultimate experiment for quantitative depth profile analysis in glow discharge optical emission spectrometry. Part I: Calibration curves
Authors: Payling Richard , Jones Delwyn G. , Gower Stephen A. 
Published: May 2005

AbstractThis is the first part of our search for an experiment that will show definitively which is the best method for quantitative glow discharge optical emission spectrometry (GDOES). Three empirical methods for producing quantitative depth profiles from GDOES data are examined: the SIMR method, the IRSID method and the most recent BHP method. All three methods give worthwhile quantitative depth profiles of thin films and coated materials. The first two methods assume that pressure does not have a significant effect on emission yield, while the third method assumes that pressure is the only significant parameter affecting emission yield. The different approaches therefore imply very different physical processes inside the lamp and it is essential for further development of quantitative GDOES that the best approach be determined. Depth profiling in GDOES is, in principle, simply bulk analysis repeated over and over as a function of depth. The three methods are therefore tested here in their ability to do bulk calibration in a range of steels and zinc–aluminium alloy standards, all at constant current. All methods worked well for steel, while the best calibration curves in zinc–aluminium alloys were obtained with pressure‐corrected IRSID and SIMR methods or a voltage‐corrected BHP method. The results suggest that emission yields depend on both voltage and pressure (and presumably current, which was not tested here in Part I).
Characterization of plasma‐deposited styrene films by XPS and static SIMS
Authors: Leggett Graham J. , Ratner Buddy D. , Vickerman John C. 
Published: May 2005

AbstractPlasma‐polymerized styrene films were studied by static secondary ion mass spectrometry (SIMS) and x‐ray photoelectron spectroscopy (XPS). The two techniques were found to yield complementary data regarding film chemical structure. Static SIMS proved to be highly sensitive to subtle changes in surface chemistry. For example, the static SIMS spectra exhibited features due to polymer cross‐linking and unsaturation. X‐ray photoelectron spectroscopy provided a good indication of the extent of oxygen incorporation into the plasma‐deposited films and characterization of time‐dependent changes in film composition.
X‐ray photoelectron and Auger electron spectroscopies and surface segregations in Pd–Rh and Pd–Ru membrane catalysts
Authors: Batirev I. G. , Karavanov A. N. , Leiro J. A. , Heinonen M. , Juhanoja J. 
Published: May 2005

AbstractAuger electron and x‐ray photoelectron spectroscopies are used to estimate the segregation trends at the surface of Pd–Ru and Pd–Rh alloys. The measurements indicate Pd segregation in the studied systems that are in agreement with the Miedema criteria based on surface tensions of pure metals. Microscopic model calculations of the surface electronic structure of the relevant alloys show the same trend. Parameters associated with the electronic structure of the alloys are used in order to explain the experimental data for the hydrogenation reaction on a Pd–Ru alloy membrane catalyst.
Inelastic electron tunnelling spectroscopy and XPS study of the oxides grown on three aluminium alloys
Authors: Pritchard R. G. , Werrett C. R. 
Published: May 2005

AbstractThree aluminium alloys, each with different major alloying components, have been studied using inelastic electron tunnelling spectroscopy (IETS) and XPS. The oxides grown on alloys containing magnesium and copper have IET spectra similar to that grown on pure aluminium and their IET spectra when doped with benzoic acid also show no differences. The alloy containing silicon gives a very different IET spectrum that has band positions similar to aluminosilicates. When doped with benzoinc acid the IET spectrum of this latter alloy also shows major differences to that of benzoic acid on pure aluminium (oxide), both in band intensities and particularly in the carboxylate stretching modes. X‐ray photoelectron spectroscopy analysis of the oxides on both the alloy thin films (IETS) and metal tokens confirms the results suggested by the IET spectra, showing that the magnesium and copper do not appear in the oxides of the first two alloys but that silicon is present in the oxide of the third and in quantities greater than that of the alloy composition.
Neural pattern recognition applied to AES depth profiling
Authors: Gatts C. , Zalar A. , Hofmann S. , Rühle M. 
Published: May 2005

AbstractNeural pattern recognition was used to analyse the low‐energy Auger spectra of a thermally annealed Si/Ni/Si layered structure measured during the acquisition of a depth profile. The purpose was to gain information about the chemical state of the elements at the interfaces by processing the data in a way quite similar to conventional target factor analysis (TFA). The new approach, however, has some important advantages: no standards are required, it is extremely fast and it is fully automatic. In principle, there is only one arbitrary parameter, the vigilance parameter ρ, which sets a threshold for the level of similarity required for assuming two spectra as belonging to the same class of data. However, the requirement that the optimal value for ρ should correspond to the maximal correlation between the experimental data set and the recalculated spectra makes the system also robust against misconclusions based on subjective interpretation of the data set, which is not always the case in TFA.
Kinetics and mechanism of the thermal degradation of poly(vinyl chloride)
Authors: Fisch Michael H. , Bacaloglu Radu 
Published: May 2005

AbstractThe kinetics of the thermal degradation of solid powdered poly(vinyl chloride) (PVC) under nitrogen was studied by thermogravimetry, rate of hydrogen chloride evolution, and rate of polyene sequence formation. These results are accommodated by a chain mechanism involving initiation by random dehydrochlorination at normal monomer residues of PVC, and a series of intermediates, each leaking to a stable conjugated polyene sequence. Structural irregularities such as allylic and tertiary chlorine are responsible for a fast initiation process at the very beginning of the degradation. Mean rate constants and activation parameters for random initiation, propagation, and termination reactions of the PVC degradation chain were calculated by simulation. Activation enthalpy/entropy correlations for the experimental data available for dehydrochlorination of chloroalkanes and chloroalkenes in the gas and in the liquid phase or nonpolar solvents and elementary reactions of PVC degradation show that initiation is an HCl elimination through a transition state of four centers requiring a synperiplanar conformation of the >CH–CCl< group, whereas propagation is a dehydrochlorination through a transition state of six centers requiring a cis configuration of the double bond.
Thermodynamic probe of intermolecular coupling in the interphase region of glass fiber reinforced polymer composites
Authors: Karian Harutun G. 
Published: May 2005

AbstractMechanical properties of polymer composites are enhanced by an interphase having a brush‐like structure, due to the entanglement of stretched compatibilizer chains and neighboring polymer molecules. Lipatov's model provides a calorimetric method for characterizing the fiber‐matrix interactions and determining the interfacial thickness, i.e., the heat capacity jump at Tg is sensitive to the combined effects of fiber glass content and intermolecular coupling in the interphase region. By a correlation between computed interfacial thickness from DSC methodology and measured tensile strength, we have a quantitative means to develop polypropylene composites having “mega coupled” tensile behavior.