bluuebunny/crossref_metadata_2025_split huggingface dataset:
A spin polarization analyzer attachment to a scanning auger microprobe
Authors: Welkie David G. 
Published: May 2005

AbstractA new, compact electron spin polarization analyzer attachment to a scanning Auger microprobe has been described. Its operation and present performance has been demonstrated using the SEMPA technique to image the surface magnetic microstructure of three different types of magnetic samples. The unique advantages of SEMPA have been identified previously; those that were illustrated in these applications are: (1) the tecnique is surface sensitive; (2) the magnetic structure is imaged independently of the surface topography; (3) the contrast and signal are large; and (4) all three components of the polarization can be determined and therefore the surface magnetic vector can be mapped. Additionally, high spatial resolution can be achieved.
Comparison of electron attenuation lengths and escape depths with inelastic mean free paths
Authors: Jablonski A. , Ebel H. 
Published: May 2005

AbstractIt is shown that calculations of electron attenuation lengths and escape depths would require modification of definitions proposed in the literature, since these definition are not universally applicable. Exemplary experimental arrangements are indicated for which more general definitions are necessary, and such definitions are proposed. A Monte Carlo program has been developed with which it is possible to estimate attenuation lengths and escape depths. A comparison of these parameters is made for photoelectrons arising from s levels.
Differential reflectometry and its application in materials science
Authors: Hummel Rolf E. 
Published: May 2005

AbstractThe differential reflectometer is briefly described, Its use as a fast, simple, and non‐destructive surface analytical instrument is stressed and several examples are provided. Among them are a study of the electronic structure of alloys, the identification and evaluation of surface films in situ, and some investigations which elucidate the damage which is inflicted on semiconductor materials and electronic devices by ion implantation and other means.
Surface characterization by means of photoemission of adsorbed xenon (PAX)
Authors: Wandelt K. , Markert K. , Dolle P. , Jablonski A. , Niemantsverdriet J. W. 
Published: May 2005

AbstractPhotoemission of adsorbed xenon (PAX) is a very sensitive probe towards the local work function. This is shown with three selected examples, namely a bimetallic Ag/Ru(001) surface, a trimetallic (Ag + Au)/Ru(001) surface and an oxygen exposed Si(111)7 × 7 surface, which prove PAX to be a powerful technique for the qualitative and quantitative characterization of surface heterogeneities on an almost atomic scale.
Atom‐Probe analysis of grain boundary segregation
Authors: Nordén H. , Andrén H. O. 
Published: May 2005

AbstractAtom‐probe micronalysis has a very high spatial resolution and equal detectivity for all elements, including the lightest. It is therefore well suited for the study of grain boundary segregation. In this paper the accuracy and spatial resolution of atom‐probe analysis are discussed, as well as the advantage of and limitations to the method. Specimen preparation methods are descibed, in particular controlled preparation using electron microscopy and pulse electropolishing. Three examples of atom‐probe studies of grain boundary segregation are given: cobalt segregation to carbide grain boundaries in cemented carbide materials; boron grain boundary segregation in austenitic stainless steels; and nickel segregation to grain boundaries in tungsten.
Grain boundary segregation in inconel 600
Authors: Caceras P. , Ralph B. , Allen G. C. , Wild R. K. 
Published: May 2005

AbstractInconel 600 is a nickel‐based superalloy which has been shown to exhibit stress corrosion cracking under certain conditions. In general the stress corrosion cracking (SCC) is intergranular in nature and hence attention has been focused on the grain boundary microstructure. A series of model alloys was produced with a range of impurity levels. Initially a high‐purity base alloy was prepared to which boron, carbon, silicon and phosphorus was added. Alloys were then examined in the mill‐annealed state and after a standard thermal ageing treatment. The grain boundary interface was analysed using scanning Auger microscopy (SAM) with the grain boundaries being exposed, only after hydrogen embrittlement, using an in situ tensile stage. The segregation of phosphorus and boron to the grain boundary surface was studied and a number of particles identified at grain boundaries. The effect of the segregants on the mechanical properties of this alloy is discussed.
Analytical study on the Fe/Ti interface in titanium‐clad steels
Authors: Kurosawa Fumio 
Published: May 2005

AbstractThe precipitates on the Fe/Ti interface in a rolled titanium‐clad steel was investigated by the potentiostatic etching with non‐aqueous electrolyte (SPEED method) followed by SEM observation and chemical analysis using a computer‐aided X‐ray microanalyser (CMA). Titanium‐clad steel (CP‐Ti/0.01% C steel) was annealed between 700 and 1000 °C for 0.5–100 h in vacuum. The cross‐section of the annealed clad steel was etched by the SPEED method and the morphology and the chemistry of the precipitates were investigated in relation to the interface by using SEM and CMA.Film‐like titanium carbide, intermetallic compunds (Fe2 Ti, FeTi) and β‐Ti containing Fe were observed on the Fe/Ti interface.The shear strength depends on the quantity of film‐like titanium carbide on Fe/Ti interface but intermetallic compunds and β‐Ti have slight influence.Thus it is considered that the embrittlement of the Fe/Ti interface was caused by (1) diffusion of carbon in steel towards the titanium layer, (2) precipitation of film‐like titanium carbide at the interface, and (3) fracture at the film.
Oxygen‐Containing species on amorphous Fe80B20 and Fe40Ni40B20 alloys during chemisorption of CO and H2
Authors: Zsoldos Z. , Schay Z. , Guczi L. 
Published: May 2005

AbstractOur study was conducted to determine the forms of the oxygen chemisorbed during the interaction of CO and H2 with FeNiB and FeB alloys in both amorphous and crystallized states using photoelectron spectroscopy. Four different kinds of oxygen were observed to exist on the samples based upon O Is binding energies (B.E.), that is, 530.1 ± 0.2 eV, 531.0 ± 0.2eV, 531.5 ± 0.2 eV and 532.0 ± 0.2 eV. The first peak is probably related to bulk iron oxide while the last one correlates directly with the occurrence of boron oxide species. The second peak is believed to be the signal of a weakly chemisorbed surface oxygen species in atomic state covering the surfaces after room temperature and low pressure (10−4Pa) oxygen adsorption. It can be the possible precursor for deep oxidation of metal. The third peak may be assigned to the oxygen species stuck to the boron‐metal interfaces having migrated from the metal surface to the surrounding boron atoms. Thereby small metal ensembles can be stabilized. In an ealier work it was established that the highest catalytic activity in the CO + H2 reaction can be related to the partially crystallized FeNiB alloys. It was supposed to be due to a special surface structure hindering the formation of the inactive graphitic species. In the light of the present study his structure can be stabilized by this boron oxide.
Equilibration processes at NiO surfaces
Authors: Nowotny J. , Sloma M. , Weppner W. 
Published: May 2005

AbstractWork function (WF) measurement were performed to monitor defect processes at the surface of NiO single crystals during re‐equilibration at elevated temperatures using gas atmospheres of controlled oxygen activities. The WF data are reported for isothermic redox experments performed at 780°C within an oxygen activity ranging between 1.74 × 102 and 4.3 × 10−4Pa.Determination of the WF is based on the measurements of the contact potential differences by the Kelvin probe. Pt was applied as a reference level. Y‐stabilized zirconia was used for calibration of the reference electrode under experimental conditions.The WF data obtained for a NiO single crystal are evaluated in terms of point defect equilibrai in the nearsurface region. It is shown that the ideal defect model is applicable for a freshy cleaved NiO surface within about 20 h of treatment at 780°C. At longer times the near‐surface defece defect model becomes more complicated involving strong defect interactions. The complications are mainly produced by segregation of bulk extrinsci defects. The outer crystal layer of the studied NiO material becomes signficantly enriched with Ca which segregates to surfaces and presumably to grain boundaries.The impact of the experimental data of the kinetics of high temperature heterogeneous processes is discussed.
Selective oxidation and chemical state of Al and Ti in (Ti, Al)n coatings
Authors: Hofmann Siegfried , Jehn Hermann A. 
Published: May 2005

Abstract(Ti, Al)N hard coatings are a promising alternative to TiN owing to an improved resistance to oxidation. In order to study the oxidation process in more detail, (Ti, Al)N coatings reactively sputter‐deposited on high speed steel substrates from a target composed of Ti:Al = 50:50 (at%) were annealed in air and in vacuum at temperatures between 500 and 800 °C. Auger electron spectroscopy (AES) sputter depth profiling as well as X‐ray photoelectron spectroscopy (XPS) studies indicate a high stability of the Ti‐N bond, whereas Al has considerable mobility in the mixed nitride. The chemical shift of the Al 2p XPS and LVV AES peaks allow a distinction between oxide, nitride and metallic states of Al. Preferential sputterin during depth profiling with 3 keV Ar+ ions resulted in a relative depletion of Al in the surface layer. It is concluded, that the Al in (Ti, Al)N is only weakly bonded to nitrogen as compared to Ti.
EXAFS study of passive films on Ni and NiMo alloy electrodes
Authors: Bosio L. , Cortès R. , Delichère P. , Froment M. , Joiret S. 
Published: May 2005

AbstractThe specular reflectivity of x‐rays at sufficiently small grazing angles is absorption‐coefficient‐dependent so that the EXAFS technique can be used to probe the surface. This method allows in situ measurements. Applications to the study of passive films on nickel and nickel‐molybdenum alloy electrodes are presented. In both cases, the passive films is found to be composed of NiO entities probably ordered perpendicularly to the electrode. Molybdenum enrichment in the surface layer is confirmed by an increase of the Mo k edge signal.
A study of the development of tribological oxide protective films mainly by Auger electron spectroscopy
Authors: Sullivan J. L. , Saied S. O. 
Published: May 2005

AbstractSince the importance of oxide film formation in the protection of contacting surfaces was recognized, there has been speculation and controversy on the nature and mechanisms of formation of such films. In this work films generated under different sliding conditions have been examined, mainly by Auger electron spectroscopy. The results show that there are two major mechanisms responsible for film formation, a homogeneous diffusion controlled mechanism and one due to agglomeration and compaction of smaller oxide particles and that system geometry is important in determining the dominant mechanism in any particular case. In both mechanisms the protective oxide film grows to critical thickness before becoming detached to form a wear particle.
Surface analysis in atmospheric environmental studies
Authors: Adams F. , De Waele J. 
Published: May 2005

AbstractSurface analysis can now be applied on the microscopical level using a number of instrumental analytical techniques. A review is given of the field of air pollution and a brief description is presented of a number of examples from our laboratory practice concerned with the characterization of air particulates and emission samples or the surface characterization of pure and modified asbestos fibres.
Application of AES micro‐analysis to interface characterization in TiSi diffusion couples: 1—Phase analysis
Authors: Quenisset C. , Naslain R. , Demoncy P. 
Published: May 2005

AbstractA detailed analysis of the silicides which are formed by diffusion at a titanium–silicon interface was performed by quantitative AES analysis. The diffusion couples were annealed in vacuum at temperatures ranging from 450 to 700°C. Semi quantitative AES spectrum/peak‐to‐peak height analytical mode was found to be not accurate enough to identify the titanium silicides particularly at low temperatures and short durations annealing. A quantitative method based on E · N(E) spectra and peak‐to‐background ratios, was used which led to more reliable results. Furthermore, the shape of the titanium Auger electron peaks were used to confirm the phase nature. After a diffusion treatment of moderate intensity, the interaction zone is mainly formed of two silicides, Ti5Si3 and TiSi2. On the contrary, under severe diffusion conditions, the disilicide phase is predominant. Finally, the growth of TiSi2 rejects oxygen (present in trace amounts in the titanium film) in the Ti‐rich side of the couple.
Auger electron spectroscopy from elemental standards. I: Theoretical calculations
Authors: Batchelor D. R. , Rez P. , Fathers D. J. , Venables J. A. 
Published: May 2005

AbstractNew calculations of electron impact ionization cross‐sections and back‐scattering correction factors have been undertaken for comparison with experiment. The ionization cross‐sections were obtained from ab initio Hartree–Fock–Slater calculations and the back‐scattering correction factors from the solution of the Boltzmann transport equation. The cross‐sections and correction factors have been calculated for the elements silicon, copper, silver and tungsten over the energy range 0.3–30 kV and the incident angle range 0–90°. These calculations are compared with previous calculations available in the literature.
A study of surface segregation in austenitic stainless steels—factors that control this segregation, its relation to grain boundary segregation and its usefulness for interpreting intergranular corrosion data
Authors: Briant C. L. 
Published: May 2005

AbstractThis paper reports a study of various factors that influence surface segregation in austenitic stainless steels. In particular four rather practical questions are addressed, all of which arose from various concerns about the corrosion behavior of these alloys. They are the following: (1) will significant segregation occur at temperatures below 500°C?; (2) is sulfur segregation affected by the presence of a strong sulfide former such as Mn?; (3) does silicon segregate to interfaces in these alloys?; and (4) do niobium additions affect phosphorus segregation in these alloys? The results show that at temperatures below 500°C, phosphorus, sulfur, nitrogen and silicon will all segregate, although at about 300°C the kinetics of segregation are becoming rather sluggish. Silicon will also segregate at temperatures at least up to 650°C. Manganese additions greatly lower sulfur segregation but niobium additions do not retard phosphorus segregation. In addition to the presentation of these results on surface segregation we consider what can be learned from them about grain boundary segregation and how they can be used to help interpret results on intergranular corrosion and stress corrosion cracking.
Lattice and grain boundary diffusion of oxygen in titanium subhydride studied by Auger sputter profiling
Authors: Wittberg T. N. , Wolf J. Douglas , Keil R. Gerald , Wang Pu Sen 
Published: May 2005

AbstractAnodic TiO2 films were grown on titanium subhydride samples under galvanostatic conditions. The samples were heat treated at temperatures between 550 and 600°C and changes in the profile of oxygen concentration as a function of depth were monitored using Auger electron spectroscopy (AES). For TiH0.87 and TiH0.96 at 600°C, the lattice oxygen diffusivity, D1 is ∼5 × 10−15 cm2 s−1 and the grain boundary oxygen diffusivity, Db, is given by δDb ∼3 × 10−18 cm3 s−1 where δ is the grain boundary width in centimeters. Using electron energy loss spectroscopy (EELS) to measure the bulk plasmon loss energy it was possible to determine the stoichiometry of the titanium subhydride substrate. Samples of TiH0.87 foil were found to dehydride somewhat upon heating to 600°C.
The surface analysis of a plasma modified contact lens surface by SSIMS
Authors: Fakes D. W. , Davies M. C. , Brown A. , Newton J. M. 
Published: May 2005

AbstractThe oxygen glow discharge plasma modification of a contact lens material has been studied using SSIMS. SSIMS provides evidence at the molecular level for the conversion of surface organosiloxane species to inorganic silica functionalities with treatment time. These findings shown an excellent correlation with a dramatic increase in surface hydrophilicity, as derived from surface energy studies, on plasma treatment. This study further illustrates the potenial of SSIMS in the determination of the molecular changes at the surface during the plasma treatment process.
Core‐level shifts and the choice of Auger parameter
Authors: Rivière J. C. , Crossley J. A. A. , Moretti G. 
Published: May 2005

AbstractThe approximation that the change in the Wagner Auger parameter α* is equal to twice the change in the extra‐atomic relaxation energy depends on the assumption of equal core‐level binding‐energy shifts. It is shown from the available published data that, in general, this assumption is incorrect, and that α* cannot be used to estimate relaxation energies accurately. If accurate relaxation energies are required, then Auger parameters such as ζ of Hohlneicher et al., or ζ′ of Sodhi and Cavell, based on the generalized Auger parameter ζ of Lang and Williams, must be used. However, for purely empirical chemical state identification in metals and semi‐metals, the various versions of α* are perfectly adequate, and indeed it matters little which version is used, since the changes Δα* with chemical state are the same for all of them within experimental error. For non‐metals there are as yet insufficient data to be certain just how useful α* might be, but for those two elements, sulphur and phosphorus, for which there are adequate data, it seems that α* on its own may not be as helpful as for the metals. In the latter case there is much less ambiguity in identification if the Wagner ‘chemical state’ diagram is used; this is particularly so for sulphur, for which the α* and β variations with chemical state seem complex.
Structural characterization of III–V semiconductor surfaces by quantitative aes
Authors: González M. L. , Alonso M. , Soria F. 
Published: May 2005

AbstractThe main objective of the present work is to extend the use of Auger electron spectroscopy as a technique capable of providing information not only about the chemical composition of III–V semiconductor surfaces, but also on surface structure by using some atoms as markers. These atoms can be either the III or V surface atoms, or/and some foreign atoms (O2, Si) when the adsorption process is site‐specific. Thus, by the interaction of O2 and Si with differently prepared GaAs[111] surfaces, we have determined besides the chemical composition of the surface bilayer, the adsorption sites, occupation sequence and the nature of the vacancy sites of the surface layers. Moreover, we have also detected anomalously low attenuation lengths of the substrate atoms. This phenomenon, observed before by other authors in different systems, was never satisfactorily explained. We present experimental evidence that the anomalous attenuation lengths are related to the structural disorder of the adsorbed layers and, therefore, that the low values observed are not correct. Consequently, great care is recommended when using attenuation lengths given by the overlayer method.
Quantitative surface analysis using electron beam SNMS: Calibrations and applications
Authors: Wilson R. , Van Den Berg J. A. , Vickerman J. C. 
Published: May 2005

AbstractA system of optics for electron impact post‐ionization sputtered neutral mass spectrometry (SNMS) has been designed and constructed. The design is based on an existing set of ‘Wittmaack‐box’‐type secondary ion mass spectrometry (SIMS) optics, commercially operational at UMIST. The system operates with ‘state of the art’ efficiency in the SNMS mode (a post‐ionization efficiency of 10−3–10−4), without significant degradation of the SIMS operation.The development stages described demonstrate many of the practical problems in the design of an electron beam post‐ionizer, involving characterization of the energy analyser used and the conditions from the optics for best secondary ion and residual gas suppression in the SNMS mode.Calibration of the SNMS mode of the system has been undertaken using standardized samples, cross‐calibrated by optical emission spectroscopy. (Typical spectra of standard stainless steel and some CuZn and CuAl alloys are presented.) These studies revealed a reproducibility of better than 10% in the relative sensitivity factors, which have been assigned to several elemental species. From these studies, a detection limit of better than 0.01 at.% was obtained for most elemental species under 10 μA Ar+ primary beam bombardment.The effects of surface roughness on the efficiency of sputtered neutral collection are reported. Studies of CuZn alloys have revealed effects on the absolute calibration and on data analysis of multicomponent materials where the individual components have differing sputter yields. This study also revealed SNMS to be a useful tool in the measurement of the sputter yields of composite materials. Studies of InAsxP1−x have been used to demonstrate the linearity of SNMS for quantitative analysis, as well as revealing the homogeneity of the layers analysed.
Surface compounds and surface precipitates on single crystal surfaces
Authors: Uebing C. , Viefhaus H. , Grabke H. J. 
Published: May 2005

AbstractThe co‐segregation of chromium or vanadium with nitrogen or carbon to (100)‐, (110)‐ and (111)‐oriented surfaces of carbon‐ and nitrogen‐doped Fe–15%Cr, Fe–3%V and Fe–3%Si–0.04%V alloys has been investigated by applying AES, low‐energy electron diffraction and SEM.Two‐dimensional epitaxially stabilized surface compounds CrN, CrC, VC and V(C, N) are formed in the temperature range 500–750°C on (100)‐oriented specimens. The surface compounds CrN, VC and V(C, N) are also formed on (110). The structures of the surface compounds are related to (100) and (110) planes of the corresponding three‐dimensional bulk compounds CrN, VC and V(C, N) and of a hypothetical bulk compoud CrC with a rock‐salt structure. In all cases, the lattice mismatch between the substrate surface and the corresponding crystallographic plane of the bulk compound is <3%. Upon surface compound formation, the (111) surface into (100) facets covered with the surface compounds.At low temperatures and high non‐metal concentrations, heterogeneous nucleation facilitates the formation of three‐dimensional precipitates at the surface.
XPS studies on cerium, zirconium and yttrium valence states in plasma‐sprayed coatings
Authors: Ingo G. M. , Paparazzo E. , Bagnarelli O. , Zacchetti N. 
Published: May 2005

AbstractX‐ray photoelectron spectroscopy (XPS) is used for investigating the valence state of the chemical elements present in 25.5 wt.% CeO2−2.5 Y2O3−72 ZrO2 plasma‐sprayed coatings as a function of the deposition temperature. Unlike the other chemical elements, cerium changes its valence state during and after the spraying process. The analysis of Ce 3d binding energies and satellite structures shows that CeO2 after spraying is either partially reduced to Ce(III) at low deposition temperature, or remains essentially unchanged at high deposition temperature. In both cases, the presence of ZrO2−x suboxides is found, which does not depend apparently on the cooling rate.