bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interfacing AEI/Kratos electron spectrometers to a microcomputer for data acquisition and processing
Authors: Evans Stephen , Elliott David A. 
Published: December 2004

AbstractInterfacing of a Research Machines Ltd. 380Z microcomputer to an AEI/Kratos ES200 electron spectrometer and Inotech multichannel analyser (MCA) is described. Comprehensive data acquisition and processing facilities are thereby provided. The microcomputer controls the MCA, the ES200 sweep ramp and the ES200 analyser kinetic energy (KE) above which the sweep is applied. The operating and processing program has been developed predominantly in BASIC, permitting the retention of more flexibility than is usual with ‘packaged’ computer systems. Facilities are provided for rapid quantitative elemental analysis by XPS following the automatic execution of repetitive sweeps over a sequence of up to 10 KE regions. Peak maximum KEs and widths are also computed, and X‐ray satellite contributions can be subtracted from the spectra. In addition, integral spectra, 5–25 point smoothed spectra and their first and second derivatives can be generated.
On depth profiling an InGaAsP‐InP heterojunction
Authors: Landers R. , Prince F. C. , Sundaram V. S. , Patel N. B. 
Published: December 2004

AbstractAn In0.71Ga0.29As0.63P0.37/In0.97Ga 0.03 As0.10P0.90 liquid phase epitaxy (LPE) grown low lattice mismatch (δa/a ≤ 0.03%) interface has been profiled using 1 keV argon ions incident at 50° to sample surface normal in a commercial Varian Auger system. It was found that an interface width of 160 Å from P (120 eV) Auger peak intensities.
The depth dependence of the depth resolution in composition–depth profiling with Auger Electron Spectroscopy
Authors: Seah M. P. , Hunt C. P. 
Published: December 2004

AbstractThe depth dependence of the depth resolution in composition–depth profiles using Auger electron spectroscopy is briefly appraised to emphasize some of the different mechanisms operating for different classes of material and to show how the use of a characterized Ta2O5 on Ta reference material can help to optimize the depth resolution. In addition it is shown that, even for flat uniformly‐layered samples sputtered under ideal conditions where the ion beam crater is flat and impurities may be ignored, five factors still limit the depth resolution: information depth, statistical effects and cascade mixing, electron stimulated desorption and sample roughening. These may each be observed to dominate at the appropriate depth for amorphous materials but, for evaporated polycrystalline metal films, the last term dominates for depths greater than 10 nm.
Ion beam induced composition changes during auger sputter profiling of thin Al films on InP
Authors: Skinner D. K. , Swanson J. G. , Haynes C. V. 
Published: December 2004

AbstractAuger sputter profiles of thin AI films on InP are presented and shown to be susceptible to an unusual type of ion beam induced interfacial distortion. It is found that recoil implantation and atomic mixing produce a differential broadening of the In and P at the interface which can seriously affect the integrity of the Auger profile. Energy shifts in the AI Auger peak indicate that this distortion is associated with AIP formation to a depth dictated by the ion beam energy and species. Experimental requirements for the reduction of interfacial distortion are discussed. We also consider the influence of the ion beam on the topography and morphology of the InP surface in relation to interfacial distortion.
Bonding of adhesive primers to aluminium substrates
Authors: Yaniv A. E. , Klein I. E. , Sharon J. , Dodiuk H. 
Published: December 2004

AbstractA study was made on the influence of sulphuric and chromic acid anodizing on the polymerization behavior of four primers (three based on epoxy resins and one on polyurethane) using IR and AES spectroscopy. AES spectroscopy has revealed that sulphur anions were incorporated in the anodic film, but no chromium anions could be detected. IR spectra for the primers on chromic acid anodic films are similar to those obtained on untreated aluminium, but a change of absorption peaks was observed for sulphuric acid anodic film substrate. Sulphuric acid anodizing has an adverse effect on the polymerization of the primers studied in this work.
Molecular orientation and structure of copper–benzimidazole films
Authors: Tompkins H. G. , Allara D. L. , Pasteur G. A. 
Published: December 2004

AbstractInfrared spectra of benzimidazole, a copper–benzimidazole complex in powder form, and a copper–benzimidazole complex which forms as a film on metallic copper are presented. The spectrum of the film on the metal exhibits peak absorbances similar to those of the copper–benzimidazole powder spectrum. It appears from relative peak heights that, in the film, the complex is preferentially oriented with the plane of the benzimidazole ring parallel to the metal surface.
Suppression of molecular ions in the secondary ion mass spectra of minerals
Authors: Metson J. B. , Bancroft G. M. , McIntyre N. S. , Chauvin W. J. 
Published: December 2004

AbstractA new approach to the suppression of molecular ions in secondary ion mass spectra of insulating specimens is reported. Using a Cameca IMS 3f instrument, with unconventional primary beam conditions and uncoated samples, it has been possible to almost eliminate the contribution of molecular ions to the mass spectrum. This has resulted in excellent discrimination for major and trace element detection in these materials, including complete resolution of the rare earth elements in a number of minerals.
Secondary ion emission of metal oxide species and their dependence on the fragment valence
Authors: Van Craen Marc J. , Adams Fred C. 
Published: December 2004

AbstractSecondary ion yields for dynamic SIMS analysis of oxidized metal and metal oxide surfaces were determined. The dependence of the ion yield with the fragment valence for molecular secondary ion species of the MxOy± type can be described by a Gaussian, whose width and maximum decreases with the number of metal atoms in the cluster. The systematics of parameters, such as the variance of the Gaussian, the total ion yield, the lattice valence and its shift with the oxidation state of the metal in the solid, were investigated. The practical use of the derived relationships is demonstrated.
Surface characterization of chemically modified (trimethylsily) silicas by 29Si solid state NMR, XPS, and IR photoacoustic spectroscopy
Authors: Linton R. W. , Miller M. L. , Maciel G. E. , Hawkins B. L. 
Published: December 2004

AbstractThe surface reactivity of hydroxyl groups on silica with trimethylchlorosilane (TMCS) is examined using XPS, FTIR‐PAS, and solid state NMR. All techniques give responses give responses which can be correlated with increasing TMS surface coverages on Lichrosorb Si 60 silica and provide detection limits of ⩽10% of a TMS monolayer. Solid state NMR is particularly suited to examining reactivity differences between geminal and single silanols. Geminal hydroxyl groups are found to be much more reactive. At higher TMS coverages approaching steric limitations (0.5 TMS monolayer), nearly 100% of the geminal sites are reacted as opposed to only 20% of the single sites. The reactive subset of single silanols appears to include hydrogen‐bonded (vicinal) groups. A mechanism is postulated to explain the apparent enhanced reactivity of geminal and vicinal silanols.
The role of surfaces and interfaces in wear, adhesion and breakdown phenomena
Authors: Le Gressus C. , Maire Ph. 
Published: December 2004

AbstractPhenomena of wear, adhesion, dielectric breakdown, etc. are dealt with by specialists in different fields (solid state physics, thermodynamics, mechanics) and it is hard to establish links between the various approaches. We have tried to achieve this by the use of surface methods, taking as the basis the insulating nature of technological surfaces and attempting to relate their technical properties (wear, adhesion, wetting, etc) to their specific physical properties (surface tension, defects, conductivity). Although in principle the physical properties investigated are accessible through chemical analysis, an explanation for the phenomena observed in practice was obtained by study of the elementary phenomena occurring on model surfaces (adsorption, segregation, charges, etc.). The points of interest were the origin of the coupling which exists between surfaces properties and volume properties, that of fracto‐emission phenomena and that of electrostatic phenomena observed during wear, adhesive stripping, etc. It is important to clarify these points, on which various theories of adherence and wear are based. Their explanation will be shown to lie in the electronic and vibrational structures of imperfect insulators and the polarization of insulators subjected to mechanical, thermal and electrical stresses. They give information about the different modes of energy dissipation in the solid and the influence of defects on the cohesion energy. The study of these different factors thus links up directly with the thermodynamic and chemical approach to the properties of insulators, which only adds to the importance of the current fall‐out from surface sciences.
Application of a crystal spectrometer to particle induced X‐ray emission analyses of GaAs crystals
Authors: Narusawa Tadashi , Ohyama Hideaki , Nakashima Hisao , Hayashi Shigeki , Koyanagi Kazuo , Kumashiro Sumio , Soejima Hiroyoshi 
Published: December 2004

AbstractThe application of a wavelength dispersive x‐ray spectrometer, instead of the conventional energy dispersive spectrometer, to particle induced x‐ray emission analyses of GaAs is reported in this paper. The apparatus and its feasibility are described in detail through measurements of standard samples, Si, Mg, and B in GaAs. The conclusion is that the technique is a good tool for light elements analysis in heavy materials such as GaAs, but proper application of the technique necessitates carefully chosen samples.
The effect on surface texture of material addition and removal processes
Authors: Zipin Richard B. 
Published: December 2004

AbstractOver the past few years there has been a continuing study of the effects of various sorts of manufacturing processes on the texture of engineering surfaces. It has been shown that surface profiles contain a history of the processes used to create them, and that the history is revealed when the cumulative distributions of the height of the surface profiles are plotted on normal probability co‐ordinates. These plots reveal various strata within the profiles which may be related to the creation processes and, in many cases, the parameters of the processes may be determined.Earlier work has considered two‐strata surfaces created by processes which either add material to the peaks or to the valleys of a surface profile or remove material from them, and three‐strata surfaces created by processes which displace material within a profile. The present work considers the three‐strata surfaces which are created by material addition or removal processes such as plating and etching which act on the surface profile as a whole. It thus completes the classification scheme for surface profiles which was originally outlined at the beginning of these efforts.The analytical technique described in this work and the earlier work on this subject are the surface metrologist's analogs to the techniques used by geologists and archeologists. They also determine history by an examination of the strata evidenced by the surfaces which they study.
Vapour development of PMMA resists under x‐ray exposure
Authors: Lehockey E. M. , Reid I. 
Published: December 2004

AbstractPoly (methyl methacrylate) PMMA films of approximately 3 μm thickness have been irradiated with Al x‐rays. The amount of vapour development is shown to increase as the initial molecular weight decreases and the rate of vapour development is shown to decrease with increasing dose. A model to describe this behaviour is presented. This model indicates that unlike the vapour development of poly (olefin sulphones), the vapour development characteristics of PMMA are not consistent with an unzipping mechanism as in the depolymerization process. Despite this there is shown to be connections between depolymerization and vapour development. Poly (methyl acrylate) PMA which has a higher depolymerization temperature is shown to vapour develop less than PMMA. Consistent with the view that irradiating reduces the depolymerization temperature, irradiated PMMA is shown to vapour develop further if it is heated after the irradiation. If the irradiation dose is high enough however (12–16 μA min cm−2), this enhanced vapour development is found to decrease. This decrease is in a dose region in which the radiation damaging process is believed to be dominated by cross‐linking. XPS analysis of the irradiated PMMA shows that, with irradiation, the oxygen content of the PMMA initially increases and then decreases. The oxygen increase is consistent with the formation of hydroxyl groups at the surface and the decrease in the oxygen content is shown to occur preferentially from the COCH3 sites of PMMA.
XPS and IR (ATR) analysis of Pd oxide films obtained by electrochemical methods
Authors: Tura Josep M. , Regull Pere , Victori Lluís , de Castellar M. Dolors 
Published: December 2004

AbstractPalladium oxide was detected by XPS and IR (Attenuated Total Reflection) analysis of the surface of a Pd electrode which was polarized in the medium 1 M KOH. This oxide set a peak of Pd 3d5/2 shifted 3.5 eV with respect to the metal which is a much higher value than those reported and obtained for PdO and PdO2. An IR absorption band of 535 cm−1 was found to be different from those reported in the literature of PdO and PdO2. The presence of this oxide is in agreement with results obtained using electrochemical methods where the existence of PdO3 has been assumed.
SIMS depth profiling of Si/SiO2/Si layers by using self‐sputtered Ga+ from a gallium liquid metal ion source
Authors: Licciardello Antonino , Torrisi Alberto , Pignataro Salvatore 
Published: December 2004

AbstractSIMS depth profiles of Si/SiO2/Si systems have been carried out using a Ga+ primary beam tracing the Ga+ yield. This ion is found to be a good marker for thin oxide layers at an Si/Si interface. In the case of thicker (7–85 nm) buried SiO2 layers, various peaks are observed for Ga+ yield. The influence of primary beam energy on the observed profiles has been investigated. A qualitative model is proposed that explains the observed profiles in terms of phenomena, such as radiation‐induced segregation, occurring in the same depth range of the cascade collision.
Study of SIMS argon ion gun for quantitative surface analysis
Authors: Zhanping Li , Jianhua Wang , Youzhe Li , Pijin Chen 
Published: December 2004

AbstractA new appartus for measuring the energy distribution of an axial ion beam is decribed in this paper. Because this apparatus is combined with an ion gun exit aperture, the assembly error has been decreased. Hence, it is possible to measure an energy spread as low as 0.36 eV. In addition, the total and axial energy distribution of the ions from the ion source and the lenses of the Kornelsen gun are measured.The variation of ion beam current, ion beam density and minimum beam diameter with a change of pressure in the ion source and ion energy have also been described.Also, a semi‐empirical formula for the relation of ion beam diameter d with ion energy E and ion source pressure P is given as
X‐ray photoelectron spectroscopy on radioactive materials using a McPherson ESCA‐36 equipped with an SSL position‐sensitive detector
Authors: Gerwing A. F. , Doern F. E. , Hocking W. H. 
Published: December 2004

AbstractA McPherson ESCA‐36 instrument has been upgraded extensively to achieve greatly enhanced x‐ray photoelectron spectroscopy (XPS) performance. An SSL position‐sensitive detector (PSD) has been retrofitted to the spectrometer in place of the standard exit slit and channel electron multiplier. A DEC LSI‐11/73 computer and a Tektronix colour‐graphics terminal with ink‐jet plotter have been substituted for the original PDP 8/e computer and peripherals. The system vacuum quality also has been significantly improved by installation of modern cryosorption and turbomolecular pumps. A self‐contained software package, based on interactive program modules, has been developed for XPS surface analysis, comprising instrument control, data acquisition and data processing. Photoelectron spectra are recorded in the non‐retardation scanning mode, utilizing the output from the central 200 channels of the 256‐channel PSD. High spectrometer resolution has been maintained by accounting for energy dispersion to second order. Calibration of the spectrometer energy scale and intensity–energy response function is discussed. The suitability of the upgraded ESCA‐36 for XPS studies of highly radioactive materials, such as used CANDU fuel, is illustrated.
Charge distribution and local and non‐local screening effects studied by means of the Auger parameter and chemical state plots
Authors: Moretti G. , Porta P. 
Published: December 2004

AbstractCopper‐ and zinc‐containing compounds, as well as other 3dn transition metal compounds, are characterized by making use of two concepts introduced first by Wagner: the Auger parameter, α = EB (photoelectron) + EK (Auger), and the so‐called chemical state plots (EK vs. EB, with the binding energy in the negative direction on the abscissa and the Auger parameter on a diagonal grid with slope equal to +1). These are useful tools to obtain information on: (1) the relative initial state charge distributions; and on (2) the relative extra‐atomic relaxation energy in the final state.In the present paper, for the first time, we show that the Auger parameter can also be helpful in the analysis of the screening mechanism in transition metal compounds.The position in the chemical state plots of different classes of compounds is discussed. The constancy of the Auger parameter for Cu(II) compounds is interpreted as further evidence of the electronic nature of the 2p3/2 final state. It can be represented by a 2p53d10L electronic structure, a local screended final state, where a charge transfer from the ligand valence orbitals toward localized d‐orbitals allows screening of the core‐hole. For copper, this relaxation energy is similar to the screening energy in the metallic state.For Cu(I) compounds, as in the case of Zn(II) compounds (d10 electronic configuration), a large dependence of the Auger parameter on the chemical nature of the ligands suggests a non‐local screening mechanism in the final state, i.e. a strong influence of electronic polarizability of the ligands on the relaxation energy. In this case, the extended s‐p cation orbitals are involved in the screening process.The charge distribution in the initial state can be studied analytically or by using chemical state plots. For example, Cu(II) compounds have about a constant Auger parameter (they fall on the same diagonal line with slope equal to +1), with the more ionic compounds at higher 2p3/2 binding energy and lower (L3M45M45, 1G) Auger kinetic energy.It appears that the Auger parameter and the chemical state plots permit an accurate characterization of the ground‐state electronic structure of cations in transition element compounds and of the screening mechanism in the final state.
An ESCA method for determining the oxide thickness on aluminum alloys
Authors: Strohmeier Brian R. 
Published: December 2004

AbstractA simple method for estimating the oxide thickness on aluminum alloys using ESCA was investigated. The method is based on a uniform overlayer model and requires only a single ESCA measurement per sample. Expressions are shown which relate the experimental intensity ration of the oxidic and metallic Al 2p ESCA peaks to the oxide thickness, for both MG and Al x‐ray sources. The method does not require ion etching or separate calibration procedures. Several practical examples that illustrate the usefulness of this method are presented. The method can also be applied to other thin film (i.e. <∼ 100 Å) metal oxide/metal systems. The maximum oxide thickness that can be measured using the method is limited to approximately three times the inelastic mean free path of the appropriate photoelectrons within the material of interest.
Raman studies of laser‐ablated ETFE (tefzel®) films
Authors: Siperko L. M. , Creasy W. R. , Brenna J. T. 
Published: December 2004

AbstractAn ethylene–tetrafluoroethylene (ETFE) copolymer film exposed to 266 nm radiation from a Nd: YAG laser (fourth harmonic) shows visible evidence of damage to the film surface in the form of blackened areas. Evidence for backbone damage to the polymer is indicated by Raman spectroscopy. MicroRaman spectroscopy of the blackened areas yields the spectrum of a carbonaceous structure superposed on the spectrum of the polymer film. Surface‐enhanced Raman spectroscopy (SERS) allows the spectrum of the damaged area to be obtained without spectral interference from the underlying film, with the resultant spectrum similar to SERS spectra of graphite fibers. The carbonaceous layer is not electrically conductive, and scanning electron microscopy shows the ablated areas to be severely cracked and discontinuous.
Determination of amino and silanol functional groups on glass via chemical derivatization and ESCA
Authors: Dang Tuan A. , Gnanasekaran Ramaswamy 
Published: December 2004

AbstractThe ESCA analysis of surface silanol (Si‐OH) and amino (NH2) functional groups on glass is either not possible or very ambiguous. These functional groups can be identified positively by using chemical derivatization in conjunction with ESCA. In addition to specificity, the technique also offers a significant decrease in detection limit. The NH2 was derivatized using penta‐fluorobenzaldehyde (PFB) and the Si‐OH was silylated with tridecafluoro‐1,1,2,2‐tetrahydrooctyl‐1‐trichloro‐ silane (TDFS). Quantification of the NH2 group can be accomplished with PFB derivatization. Only a relative comparison of the silanol group on glass can be carried out in TDFS silylation owing to the uncertainty in the completion of this reaction in the ESCA sampling depth.
Influence of ion mixing, ion beam‐induced roughness and temperature on the depth resolution of sputter depth profiling of metallic bilayer interfaces
Authors: Cirlin Eun‐Hee , Cheng Yang‐Tse , Ireland Philip , Clemens Bruce 
Published: December 2004

AbstractTo study the factors limiting the depth resolution of sputter depth profiling, we have examined the influence of ion mixing, ion beam‐induced roughness and temperature on the interface resolution of metallic bilayers consisting of Pt on top of Ni or Ti. We studied Pt/Ni and Pt/Ti interfaces because Ni and Ti have similar ballistic properties, including atomic mass and number, but the heat of mixing, ΔHm of Pt/Ni and Pt/Ti are significantly different, ‐7 and ‐122 kJ g‐1 at.‐1, respectively. We observed that the measured interface width for Pt/Ti is ∼2.5 nm wider than that of Pt/Ni under identical experimental conditions, indicating the importance of the heat of mixing during ion mixing. Furthermore, for the given sputtering geometry we found that the interface widths were proportional to the square root of the Pt layer thickness. This thickness dependence was absent when the sample was rotated during sputtering, suggesting that the thickness dependence was largely due to roughness caused by unidirectional sputtering. We also investigated the influence of substrate temperature and found a small (0.7 nm) decrease in interface width at 150 K relative to that at 300 K, which may be due to reduced preferential sputtering and a smoother surface. Our studies show the importance of thermodynamic parameters in low‐energy ion mixing and support our earlier conclusion that diffusion in a thermal spike is a dominant mechanism in low‐energy ion mixing, just as it is at high energies in these systems.