bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electron beam effects during analysis of glass thin films with auger electron spectroscopy
Authors: Ohuchi F. , Ogino M. , Holloway P. H. , Pantano C. G. 
Published: December 2004

AbstractMigration of sodium in thin films of soda‐silica glass deposited on a stainless steel substrate has been studied. The amounts of charge trapping and local heating were a strong function of beam parameters for thin films. For example, the time required for the sodium Auger signal to decay to 50% of its initial value increased as the beam energy was increased or as the current density was decreased. The rearrangement of sodium due to charge trapping was calculated and compared to experimental data. The calculated and experimental data agree well and indicate that fields of ∼105 V cm−1 exist during analysis. The depth distribution of sodium indicates that either electrons or ion bombardment can cause sodium migration during analysis. The cross‐section for electron‐induced desorption was measured to be 3 × 10−20 cm2 for sodium in this glass, therefore it is only important at very high current densities.
Composition profile across a NiO/Ni interface determined from Auger electron peak shape analysis
Authors: Röll Klaus , Pamler Werner 
Published: December 2004

AbstractThe composition depth profiles of NiO layers grown on Ni metal were determined by AES and ion beam etching. As the shape of the Ni peak varies significantly with composition, a simple peak‐to‐peak (p‐p) analysis seems not to be applicable. Therefore the complete peak shape at any point of the profile was fitted by a superposition of a metal and an oxide peak. From the fit, the NiO content in the Ni matrix can be determined. Thus a quantitative analysis can be provided from the peak shapes. In addition to the more rigorous treatment, formulae for the p‐p amplitude have been developed which allow for the superposition of Ni and NiO peaks. Then an analysis can also be obtained with reasonable accuracy using the p‐p amplitudes only. The methods can be applied in materials where the peak shape changes due to a superposition of peaks.
Probing the influence of thin overlayers on the results of quantitative XPS analysis without reference samples
Authors: Ebel Maria F. 
Published: December 2004

AbstractIn contrast to physical methods with large information depths, the results of quantitative XPS analysis are strongly influenced by oxide and/or contamination overlayers with a thickness of 1‐2 monolayers. A new method is introduced which allows the determination of a value d/(Λref cos ε)without the application of the variable take‐off angle technique. The significance of the results and their associated errors are discussed.
Elastic peak electron spectroscopy for auger electron spectroscopy and electron energy loss spectroscopy
Authors: Gergely G. 
Published: December 2004

AbstractElastic peak electron spectroscopy deals with the spectra of secondary electrons in the neighbourhood of Ep primary energy and determines them in absolute units based on the Ne percentage of elastically reflected electrons. A procedure is described for evaluating elastic peak spectra. Experimental results on graphite, Si, Ge, stainless steel, Mo, W and Au polycrystalline samples are presented in the medium energy (Ep = 1–3 ke V) range. Spectra were measured with a cylindrical mirror analyser operated in the direct current mode. For elements (Si, Mo, etc.) Ne is determined mainly by the atomic number Z, Ne(Z)∼(Z – 26)0.65 was found for Z ≥ 26 and Ep = 3.1 ke V. The Ep dependence of Ne can be approximated by a power law Ne(Ep)∼Ep−β(Z), with β(Z) varying between 2 and 0.4 for the Z = 4–79 atomic number range. The elastic peak is composed of electrons escaping from a surface layer determined by the inelastic mean free path of primary electrons. Using Seah's values and from the Ne experimental data the backscattering cross‐sections were determined. They varied between 5 × 10−20(C)−2.8 × 10−18 cm2 (W, Au). Some new results are presented on the volume plasmon losses. In Si and Ge the mean free path of medium energy electrons is determined by the first volume plasmon loss, whereas in metals the contributions of other loss processes are important. It is practical to use the elastic peak and Ne as references for Auger and loss peaks allowing the estimation of ionization cross‐sections in Auger electron spectroscopy.
Rutherford back scattering and auger electron spectroscopy analysis of the oxygen distribution in the Al—Ag system evaporated at 10−4 Torr
Authors: Oliver Alicia , Santibáñez Federico Garcia 
Published: December 2004

AbstractAn analysis of the Al‐Ag system on thin films carried out through Rutherford back scattering and Auger electron spectroscopy combined with ion sputtering is reported. The films were prepared by evaporation on vitreous carbon under vacuum pressures of 1 × 10−4 Torr. The results show different distributions of oxygen depending upon the order of A1 evaporation.
Interface analysis of high insulating garnet materials using secondary ion mass spectrometry
Authors: Tolle H. J. 
Published: December 2004

AbstractIn this study, secondary ion mass spectrometry (SIMS) has been used to investigate the interface inhomogeneities of several μm thick layers of magnetic garnets grown on non‐magnetic garnet substrates. The epitaxial layers have the general composition Y3−x−zLaxPbzFe5−y Gay O12, whereas the substrate consists of Gd3Ga5O12. Bombardment of an insulator causes the sample to become charged, leading to loss of the secondary ion signal. This charge has to be compensated for by a simultaneous bombardment of the sample surface with electrons. The dependence of the Pb content (208Pb+) at the film‐substrate interface has been investigated as a function of the dipping parameters and the lattice mismatch. Layers are grown onto films with identical melt compositions but with different supercoolings. In all cases an enhanced Pb concentration at the beginning of the film growth process was found. With a specially grown inhomogeneous sample we were able to show the direct substitution of Pb and Y. The investigation of Ga within the transient layer is particularly difficult because of the high amount of this element in the substrate. The calibration of the count rate scale into formula units has been achieved by electron probe microanalysis (EPMA).
The application of inelastic electron tunnelling spectroscopy (IETS) to the study of surfactant adsorption upon an aluminium oxide surface
Authors: Langley A. J. , Oxley D. P. , Smith E. G. 
Published: December 2004

AbstractInelastic electron tunnelling spectroscopy has been applied to the study of sodium dodecanoate (laurate) adsorption, from aqueous solution, upon an aluminium oxide surface. AlAl2O3Pb tunnel junctions, whose oxides have been exposed to aqueous solutions of sodium dodecanoate are found to exhibit a maximum in resistance with increasing solution concentration. Spectral quality is dependent upon solution concentration, and optimum spectra are only obtained when junction resistance is near this maximum. The resistance maximum and decline in spectral quality with increasing solution concentration, are explained in terms of surfactant aggregation at a critical concentration. An optimum IET spectrum of sodium dodecanoate is presented and compared with the bulk infra‐red and Raman spectra of aluminium dodecanoate. A chemisorption mechanism is proposed. Other surfactants have also been investigated. These were sodium octadecanoate (stearate), sodium dodecyl sulphate and sodium hexadecyl sulphate. Problems specific to the application of inelastic electron tunnelling spectroscopy to these surfactants are reported.
Optical in situ sputter rate measurements during ion sputtering
Authors: Kempf J. 
Published: December 2004

AbstractA laser optical technique is applied to secondary ion mass spectrometry/Auger electron spectroscopy for in situ sputter rate measurements. Phases and reflectances as measured during sputtering of opaque and transparent material give reliable results yielding the sputter rate interface position and interface region width. For opaque material there is a simple linear relation between the phase and the sputter rate. In the case of transparent material the sputter rate is determined from the phase or reflectance by using a more complex calculation.
Ion bombardment induced surface topography modification of clean and contaminated single crystal Cu and Si
Authors: Lewis G. W. , Kiriakides G. , Carter G. , Nobes M. J. 
Published: December 2004

AbstractAmong the several factors which lead to depth resolution deterioration during sputter profiling, surface morphological modification resulting from local differences of sputtering rate can be important. This paper reports the results of direct scanning, electron microscopic studies obtained quasi‐dynamically during increasing fluence ion bombardment of the evolution of etch pit structures on Si and Cu, and how such elaboration may be suppressed. It also reports on the elaboration of contaminant‐induced cone generation for different ion species bombardment. The influence of such etch pit and cone generation on achievable depth resolution is assessed.
Some aspects of a quantitative LEIS study of the potassium segregation at the V6O13(001) surface
Authors: De Gryse R. , Landuyt J. , Vandenbroucke L. , Vennik J. 
Published: December 2004

AbstractThe influence on the low energy ion scattering (LEIS) signal intensities of a potassium segregation is studied at 800 K. It is possible to alter the potassium surface concentration by means of electron stimulated desorption. The higher this concentration, the lower the absolute count rate of the complete LEIS spectrum. This observation suggests that, in the case of helium scattering at the V6O13(001) surface, Auger neutralization processes and/or adiabatic resonant transitions are active. This fact allows the calculation of an upper and a lower limit for the ratio of the scattering cross sections for oxygen and vanadium. From a comparison with theoretical predictions based on the Molière or Born—Mayer approximation of the Thomas—Fermi—Firsov potential, it follows that, under the given circumstances, low energy helium scattering is better described using the Molière approximation. By using this potential model, it is also found that at 800 K this potassium segregation is quite important giving rise to a steady state concentration of about one potassium atom per V6O13(001) surface unit cell.
Application of SIMS to heavy metal tellurides
Authors: Holland R. , Blackmore G. W. 
Published: December 2004

AbstractA Cameca 3F imaging ion microanalyser has been used for the quantitative analysis of epitaxial layers of cadmium mercury telluride (CMT) and related materials on a variety of substrates. CMT has low thermal stability, readily losing Hg, and the erosion rate is unusually high. Nevertheless, satisfactory, reproducible, depth profiles are obtainable under constant erosion conditions. The positive secondary ion spectra of CMT, CdTe and HgTe are complicated by extensive interference by molecular ions and multicharged ions of the numerous isotopes of the matrix elements. The energy distributions of many of these are anomalous and the intensity varies non‐linearly with primary‐ion current density. It is shown that this anomalous behaviour is characteristic of the elements rather than the matrix. Wittmaack's theory of post‐sputtering ionization is confirmed by demonstrating that the intensity in these cases is proportional to the square of the primary‐ion current density and the effect is quantified for a variety of multicharged ions. Advantage has been taken of the low energy cut‐off of these species to overcome mass spectral interferences. Examples are given of the quantitative variation of trace elements through epitaxial layers as part of an on‐going analytical programme.
Correction factors and sputtering effects in quantitative auger electron spectroscopy
Authors: Holloway Paul H. , Hofmeister Susan K. 
Published: December 2004

AbstractQuantification of Auger electron spectroscopy data from silver‐gold binary alloys has been studied. It is shown that the Auger data accurately reflect the bulk composition of scribed surfaces when the intensities of elemental standards are corrected for variations in the atomic density, electron escape depth and backscatter factor. It is also shown that gold is enriched in the surface region during sputtering with either argon or neon ions but the enrichment is less when sputtered at 110 K than at 300 K. Transients are observed in the concentration of gold and silver in the surface region when the ion energy is changed from 500 eV to 2000 eV. These sputtering effects (commonly called preferred sputtering) are interpreted as resulting from a combination of recoil implantation and surface segregation.
A simple background correction for AES peak height measurements
Authors: Labohm F. 
Published: December 2004

AbstractA very simple background correction is described, which largely removes the error introduced by the AES background signal. The correction consists of adding a fixed amount, equal to the change in the background across the AES line, to the measured peak height. The correction is particularly important for the measurement of small coverages of elements displaying AES lines in the low energy range of the spectrum. No computer is necessary. An example concerning C on Ni(100) is given.
Core level binding energy shifts in dilute tin alloys
Authors: Hegde R. I. 
Published: December 2004

AbstractX‐ray photoelectron spectra of Cu95Sn5 and In95Sn5 alloys have been recorded using a VG Scientific ESCA‐3, MK II electron spectrometer. The binding energy of Sn 3d level in these alloys is compared with that in pure Sn(ß). From the above results, and also from those published earlier, it is clear that the binding energy shift depends on the electronegativity difference, the coordination number and also the interatomic distance. A simple empirical equation was arrived at to get the best fit with the experimental data. In general the agreement between the calculated and measured binding energy shifts is quite satisfactory.
Preparation of self‐supporting anodic barrier films on aluminium for backscattering analysis
Authors: Shimizu K. , Skeldon P. , Thompson G. E. , Wood G. C. 
Published: December 2004

AbstractA technique for the preparation of self‐supporting windows of anodic barrier films on aluminium, which are essential for the precise interpretation of Rutherford backscattering data, is described. The generation of the window comprises several steps which include: (1) electropolishing of the superpure aluminium specimen in a perchloric acid/ethanol mixture; (2) masking a region of surface of the electropolished specimen with ‘Lacomit’ paint; (3) anodizing to develop a barrier‐type anodic film over the exposed aluminium surface; (4) removal of the paint to reveal the non‐anodized region on one face of the aluminium specimen which is then removed by electropolishing to leave the film window. Following this procedure, self‐supporting windows of anodic films, free from the aluminium substrate, having effective diameters up to about 10 mm, are produced. It is shown that the use of the self‐supporting window enables the Rutherford backscattering technique to be used to its full potential for the analysis of the barrier‐type anodic films, enabling Al and O profiles through the film to be resolved clearly.
Element‐Specific broadening effects in SIMS depth profiling of light impurities implanted in silicon
Authors: Wach W. , Wittmaack K. 
Published: December 2004

AbstractBeam‐induced broadening effects in SIMS depth profiling have been studied for eight impurities (Li through Al) implanted in amorphized silicon at energies between 1 and 15 keV. Depth profiling was performed under Ar+ (⩽2.5 keV) or O (⩽3 keV) impact. In selected cases (Li, N) the effect of the probe energy has also been investigated. The measured profiles show exponential tails. The decay length γ characterizing these tails exhibits strong oscillations when plotted as a function of the atomic number of the dopant. Maxima are seen for N and O (γ ≃ 7 nm) as well as for Mg (γ ≃ 13 nm), minima for B and Na (γ ≃ 2 nm). The results suggest that the observed effects are due to a yet unpredictable combination of collisional mixing, defect‐assisted diffusion and selective sputtering.
Imaging XPS—A new technique, I—principles
Authors: Gurker N. , Ebel M. F. , Ebel H. 
Published: December 2004

AbstractXPS imaging promises to be a powerful analytic tool because it enables specific information on both elements and bonding to be recorded on a two‐dimensional distribution map. As far as the authors are aware, the only scanning XPS method to date which has been found to be practical is essentially a scanned‐particle‐beam method, like scanning AES, and it is only applicable to thin film specimens. This paper provides the basic ideas of a new imaging XPS technique based on a quite different concept. It will be applicable to any kind of specimen that can be analysed in a conventional XPS system. It makes use of the dispersion properties of a spherical condenser‐type spectrometer and applies a two‐dimensional electron detection device for decoding the energy and emission position of an analysed photoelectron. Experimental arrangement and theory of operation are presented.
In situ characterization of electrode–electrolyte interfaces using spectroscopic techniques
Authors: Miles R. 
Published: December 2004

AbstractA review of ultraviolet/visible, infra‐red and Raman spectroscopic techniques (excluding ellipsometry), applied to the in situ characterization of immersed electrodes is presented. Literature reports involving transmission and internal reflectance at optically transparent electrodes, and also external specular reflectance at planer electrodes both in the visible and in the infra‐red spectral regions are described. Rman techniques covered include not only recent developments in surface‐enhanced Raman scattering but also unenhanced Raman scattering, resonance Raman scattering and other non‐linear processes. Specialized instrumentation requirements are discussed and experimental methodology relevant to the characterization of electrochemical systems is outlined. The report concludes by highlighting the advantages and limitations of the various in situ spectroscopic techniques indicating likely areas of development in the future.
Adsorption of NO on a Rh‐10% Pt (111) surface: Non‐uniform spatial distribution
Authors: Holloway P. H. , Williams F. L. 
Published: December 2004

AbstractMost studies of chemisorption now use single crystals in order to distinguish the effects of crystallite orientation upon absorption and to have a ‘large, uniform’ surface for measurement. Also, many of the analytical techniques require surface areas 1 mm in diameter for measurements. Most investigators implicitly assume that a single crystal will provide a uniform surface over these dimensions. This is not always true as will be shown in this case for NO absorption on Rh‐10% Pt (111) crystals. Therefore, the purpose of this communication is to show that high spatial resolution surface analysis can be very useful in studying surface/gas reactions, even on single crystal surfaces.
Surface quantitative analysis of CrO systems by XPS
Authors: Battistoni C. , Cossu G. , Mattogno G. , Paparazzo E. 
Published: December 2004

AbstractA comparison among O/Cr atomic ratios obtained from XPS Cr 2p3/2 and O 1s spectra in pure inorganic compounds, employing the Elemental Sensitivity Factors approach and the so‐called ‘First‐Principles Model’ is reported.
Use of a fast atom beam in ion microscopy (FABIM) for analysis of poorly conducting materials
Authors: Degrève F. , Lang J. M. 
Published: December 2004

AbstractA Cameca IMS3f ion microscope was modified to allow the analysis of poorly conducting materials. A neutralization chamber within the primary ion column constitutes a fast atom beam (FAB) source. The insertion of a thin metallic diaphragm between the sample and the sample holder minimizes the charge build‐up. With these simple and cheap modifications, it is possible to change instantaneously from ion to neutral beam excitation for the same analysed area. The characteristics of the primary neutral beam were evaluated and the analytical possibilities using positive and negative secondary ions were investigated on various poorly conducting materials (mineral, multilayered glass, organic). The unique advantages of combining FAB and Ion Microscopy (FABIM) are illustrated: imaging capability, low detection limit, mass spectra at low and high resolution and depth profiles on very small areas. Suggestions are proposed to improve the performance of this preliminary FABIM design.
Oxidation of Ni3Al at low and high oxygen pressures
Authors: Venezia A. M. , Loxton C. M. 
Published: December 2004

AbstractOxidation of stoichiometric Ni3Al performed at elevated temperatures in low oxygen partial pressure and in atmospheric oxygen has been studied by x‐ray photoelectron spectroscopy, auger electron spectroscopy and x‐ray diffraction. At low oxidation pressure only the aluminum oxide is found although there is evidence for a phase change at temperatures above 600°C. At atmospheric pressure, NiO, NiAl2O4 and Al2O3 are obtained. The different behavior is discussed in terms of the relative standard free energy of formation of the oxides.
Nitrogen 1s charge referencing for Si3N4 and related compounds
Authors: Donley M. S. , Baer D. R. , Stoebe T. G. 
Published: December 2004

AbstractThis paper describes the method used to produce a Si3N4 standard for use as a reference material in XPS measurements of silicon nitride related compounds. The reference material was made by high dose ion implantation of N+ into a (100) Si wafer and annealing the wafer at 1150°C. Rutherford back‐scattering measurements and an Auger depth profile confirmed that after the anneal a subregion of Si3N4 was formed. X‐ray photoelectron spectroscopy (XPS) spectra were collected for Si 2p, N 1s and Si KLL lines. Signals from both elemental Si and Si3N4 were observed, with no indication of specimen charging. The N 1s binding energy was determined to be 398.5 eV. Modified Auger parameter plots of the data showed results consistent with other careful measurements for Si and Si3N4. Because data from several studies indicate that the N 1s peak is relatively insensitive to minor compositional changes, the N 1s line can be used as a charge reference for the analysis of Si3N4‐based materials. This charge reference can reduce the uncertainty in binding energy measurements on these generally insulating materials to ±0.1 eV.
Use of the Macintosh computer for data acquisition
Authors: Baun W. L. 
Published: December 2004

AbstractMS‐DOS based computers such as the IBM AT or XT and their clones have become commonplace for control and data acquisition applications with surface analytical instruments. These computers are especially applicable because of the wide availability of versatile special purpose electronic boards which simply plug into slots in the computer. The Apple Macintosh has numerous characteristics such as high resolution graphics which make it ideal for instrument control and data acquisition. However, because the Macintosh is a closed architecture computer (open architecture version announced March 1987) boards may not be added and therefore other approaches must be used. Four systems are evaluated here. Two more systems are described, but have not yet been evaluated. Aspects such as hardware, software, communications methods and cost are considered. Most approaches utilize a dedicated microcomputer with serial communication through the modem or the extremely high speed small computer interface (SCSI) port of the Macintosh. The data which is returned to the Macintosh may be manipulated (smoothing, transform, etc.) and plotted by the program or transferred into a data file of a program such as Microsoft's Excel. Even more sophisticated data presentation may be obtained by exporting the data to a versatile plotting program such as CricketGraph.