bluuebunny/crossref_metadata_2025 huggingface dataset:
Internal Shearing during Shaped Charge Jet Formation and Break‐up
Authors: Hirsch Eitan
Published: December 2004

During jet formation and elongation, the shaped charge linear material is subject to forces which vary extremely in both magnitude and direction. As a result, the direction in which the slip planes are formed in the material, changes so as to comply with the force direction and strength. By following the direction of the slip planes from the beginning of liner motion until the jet breaks up, it is possible to suggest a description of the internal changes occurring in the material during liner collapse, jet formation, and jet elongation. The mechanism obtained by this study may account for the slight systematical deviation by a jet from the original shaped charge axis of symmetry, such as has been measured very accurately using the orthogonal synchro‐streak technique (OSST) developed by Held. The mechanism may also explain some jet details observed in OSST photographs and flash radiographs. The modeled mechanism identifies the possibility that some basic differences may exist between the break‐up process occurring in expanding rings and shells and the break‐up process occurring in shaped charge jets.
A study of Explosive Compositions Containing Ammonium Perchlorate
Authors: Gimenez P. , Lecume S. , Groux J.
Published: December 2004

Five compositions incorporating octogen with an energetic binder, a reference composition and four compositions containing ammonium perchlorate, were studied experimentally by measuring the detonation velocity versus the diameter, by performing the cylinder test and a frontal projection test using a VISAR interferometer. The results obtained are treated in the frame means of the ZND phenomenological model extended to nonideal explosives and by using an adaptation of Kamlet's method. The conclusions drawn from this study are:

– the phenomenological model is in line with the experimental results,

– AP is entirely decomposed in the steady‐state zone,

– the recombination reactions between the oxygen, released by the AP, and the carbon, released by other components, occur completely in the steady‐state zone in the case of small grain‐size AP (10μm),

– these reactions are prolonged, for a few microseconds, in the non steady‐state zone in the case of large grain‐size AP (200μm),

– In this case, the heterogeneity of the material is reflected in the structure of the detonation wave which shows a Von Neumann shock with a finite rise time (30 ns).

The methodology developped in this work can be used for the study of the majority of non ideal explosives.
Structure and Tautomerism of ANTA (aminonitrotriazole)
Authors: De Paz Jose‐Luis G. , Ciller Juan
Published: December 2004

Energy and dipole moment calculations show 3‐nitro‐5‐ amino‐1,2,4‐triazole is the most stable tautomer of ANTA either in the gas phase and polar solvents, in agreement with X‐ray findings. Our calculations predict that the 5‐nitro‐3‐amino‐1,2,4‐triazole tautomer is more sensitive to shock or impact. Some discrepancies between semiempirical (AMI and PM3) calculations and ab initio (up to 6‐31G*//6‐31G) are studied.
Explosive properties of the compositions CCl4 + Al + ZnO
Authors: Syczewski M.
Published: December 2004

The compounds CCI4 + Al + ZnO were suitably prepared, so that its ability to detonate could be investigated. The detonation velocity (D) dependence on the charge density (ρ) has been established. The increase of density above 1.8 kg/dm3 particle velocity was measured. Extraordinarily low parameters of detonation are explained by the special peculiarity of the explosion products.
Testing the Precision Initiation Couplers
Authors: Held Manfred
Published: December 2004

It is possible to properly test a Precision Initiation Coupler (PIC) for its detonation profile and the rotational symmetry of its detonation wave using the Multi‐Streak and/or Flash‐Gap‐Technique both with central linear streak line and circle streak which is comprised of dots for better evaluation.
Modified SDM Model for the Calculation of shaped charge hole profiles
Authors: Schwartz Wolfgang
Published: December 2004

Shaped charge craters can be calculated in regards to depth and diameter profile using the SDM model named after Simon, DiPersio, and Merendino(3). Crater profiles calculated using the SDM formulae exhibit a systematic deviation if compared with test data from firings of certain MBB (now DASA) shaped charges into RHA.

The calculated craters feature a significantly more trumpet‐shaped profile than the measured holes in RHA This phenomenon is caused, at least partly, by the assumption in the SDM model that the break‐up time and the jet diameter after break‐up are constant. Radiographs of particulated jets provide evidence that the diameter is generally not constant, rather increases from tip to tail. The evaluation of such radiographs also leads to the conclusion of variable break‐up times.

Changing those two assumptions a modified set of SDM formulae was developed so that calculated and experimental crater profiles are in better agreement for the above mentioned MBB shaped charges.
Impact Testing of Explosives and Propellants
Authors: Coffey C. S. , De Vost V. F.
Published: December 2004

The drop weight impact test is the simplest and easiest test that can be performed on small quantities of explosives or propellants, and yet it has only a minimal role in assessing explosive sensitivity or performance. This paper examines the drop weight impact test as it is currently used, describes its major flaw, and suggests an alternative test that holds the promise of providing the impact energy required to ignite an energetic material. Other impact tests are described. One of these, the Ballistic Impact Chamber Test, measures the rate of reaction and extent of reaction during impact. This test demonstrates that during impact there are two forms of initiation reactions that occur, one that is very fast and is likely due to direct impact‐shear initiation of the crystalline solids in the sample. The other, a much slower component, is thought to arise due to burning of the sample.
Preheating Sensitization of a TATB Composition. Part Two: Microstructure Evolution
Authors: Le Gallic Christian , Belmas Robert , Lambert Philippe
Published: December 2004

This paper is devoted to a review of microstructure observations performed on a TATB composition submitted to thermal and combined thermal/mechanical stimuli. Effects are identified and quantified in terms of decomposition extension and microstructure evolution (porosity, shear bands, grains shape and orientation, anisotropy …︁). Several complex mechanisms and important transformations are exhibited as a function of temperature, heating duration and shock wave intensity. Conclusions on decomposition mechanisms are directly derived from these observations.
Study of Jet Interaction with Interlayer Material of Bulging Armor
Authors: Yadav H. S.
Published: December 2004

The paper presents an analytical approach for determining the effects of different properties of inert material of bulging armor sandwich on its efficiency against a shaped charge jet. The crater and shock wave parameters have been investigated. A theoretical relation for calculating the energy of the shock wave, produced by the jet impact, in the inert material has been derived on the basis of continuity of pressure and particle velocity at the interface of jet and inert material. This relation reveals that the higher the velocity of the jet the greater is the amount of energy in the shock wave. The energy of the shock wave also increases with increase of density and decrease of strength of the inert material. The shock energy has been found to further depend on the constants of equation of state of the inert material, (us=a+b u).
Aspects of the Tribology of the Plastic Bonded Explosive LX‐04
Authors: Hoffman D. Mark , Chandler Jeffrey B.
Published: December 2004

The dynamic coefficient of friction, μd, of the plastic bonded explosive (PBX) LX‐04 was measured on stainless steel, aluminum, Teflon and the explosive itself as a function of temperature between ambient and 135 °C at a rotational speed of 0.0025 rad/s−1. An optical profilometer was used to analyze surface roughness. LX‐04 is a composite of the explosive 1,3,5,7‐tetranitroazacyclooctane (HMX) and Viton A in an 85/15 weight ratio. For LX‐04 on stainless steel, μd decreased from 0.38 at ambient to 0.18 at 95 °C, then was nearly constant to about 125 °C, where the coefficient began to increase again. The opposite behavior was observed for aluminum. Against Teflon μd was nearly constant from ambient to 65 °C at 0.43, and then decreased to 0.17 from 100 °C to 135 °C. Against LX‐04 itself the coefficient of friction averaged 0.64 at temperatures between 35 °C and 95 °C, but tended to increase during the measurement, probably due to adhesion of the Viton to itself. Above 95 °C the coefficient dropped off and became nearly constant again at 0.16 up to 135 °C. Measurements on stainless steel with the mock explosive RM‐04‐BR, a composite of cyanuric acid and Viton A, and with the same weight ratio as the actual explosive, compared reasonably well with the explosive itself.
Neutralization of NGF‐TrkA receptor interaction by the novel antagonistic anti‐TrkA monoclonal antibody MNAC13: A structural insight
Authors: Covaceuszach Sonia , Cattaneo Antonino , Lamba Doriano
Published: December 2004

MNAC13, a mouse monoclonal antibody, recognizes with high affinity and specificity the neurotrophin receptor TrkA and displays a neutralizing activity toward the NGF/TrkA interaction. Detailed knowledge of the molecular basis determining the specificity of this antibody is of importance because of its potential use as a modulator of the TrkA‐mediated NGF activity. Here, we report a full biochemical and structural characterization of the MNAC13 antibody. Epitope mapping studies, by serial deletion mutants and by phage display, reveal a conformational epitope that is localized on the carboxy‐terminal region of the first immunoglobulin‐like domain (d4) of TrkA. The X‐ray crystal structure of the MNAC13 Fab fragment has been determined and refined to 1.8 Å resolution. The antigen‐binding site is characterized by a crevice, surrounded by hydrophilic‐charged residues on either side, dipping deep toward three mainly hydrophobic subsites. Remarkably an isopropanol molecule has been found to bind in one of the hydrophobic crevices. Overall, the surface topology (shape and electrostatic potential) of the combining site is consistent with the binding data on TrkA ECD serial deletions mutants. The structure of the MNAC13 Fab fragment may assist in the rational structure‐based design of high affinity humanized forms of MNAC13, appropriate for therapeutic approaches in neuropathy and inflammatory pain states. Proteins 2005. © 2004 Wiley‐Liss, Inc.
Acaricide mode of action
Authors: Dekeyser Mark A
Published: December 2004

The last few years have seen the introduction of an unprecedented number of new classes of acaricides with novel or under‐exploited modes of action, discovered by traditional screening. Acaricide research has uncovered several unrelated compounds that possess improved properties. Pyridaben, acequinocyl, diafenthiuron, etoxazole, spirodiclofen and bifenazate, in particular, are acaricides that are safe to beneficials, have low mammalian toxicity and short environmental persistence. Many of the new acaricides appear to affect mitochondrial respiration, and previously unknown targets affecting mite growth and development have been identified, offering new opportunities for mite control. Copyright © 2005 Society of Chemical Industry
On the preparation of electron sensor using LiRbSO4 samples
Authors: El‐Muraikhi M. , Kassem M. E. , Gaafar M. , Abdel Gawad M. M. H. , Ragab I. M.
Published: December 2004

The dielectric spectroscopy of metal–metal sulfate LiRbSO4 samples are described with particular emphasis on sensor performance to be used in the field of radiation. The obtained results as the effect of different electron energy beams at fixed dose, 0.5 Gy, showed abrupt change of the electrical properties (electrical conductivity, capacitance, and loss tangent). The results can be explained on the basis of radiation‐induced defects followed by radiation quenching. The prepared samples can be used in the field of radiation dosimeter.
Microwave‐assisted Cu (I) Catalyzed Solvent‐free Three Component Coupling of Aldehyde, Alkyne and Amine
Authors: Ju Yuhong , Li Chao‐Jun , Varma Rajender S.
Published: December 2004

Direct Grignard type addition of terminal alkynes to in situ generated imines, from aldehydes and amines, occurs under microwave irradiation using CuBr alone in a one‐pot operation. This solventless approach provides ready access to propargylamines and is applicable both to aromatic and aliphatic aldehydes.
Thickness measurements on layered materials in powder form by means of XPS and ion sputtering
Authors: Cross Y. M. , Dewing J.
Published: December 2004

A model for the quantitative analysis of XPS data from coated spherical particles is described. The limitations of the application of flat surface intensity equations to this system are discussed. The predictions are compared with experimentally derived XPS results for SiO2O3 coated TiO2 powder samples. Sputtering profiles for these systems are presented and interpreted.
Auger electron spectroscopy (AES) an appraisal
Authors: Alford N. A. , Barrie A. , Drummond I. W. , Herd Q. C.
Published: December 2004

Electron induced Auger electron spectroscopy of solid surfaces has proved a valuable analytical technique over the past ten years. In this paper the state of the technique is reviewed and compared with other methods of Auger spectroscopy, e. g. X‐ray induced AES.
A multichannel electro‐optical detector for rapid acquisition of X‐ray photoelectron spectroscopy data
Authors: Ceasar G. P. , Weber J. , Talmi Y.
Published: December 2004

An electro‐optical detector easily adaptable to any hemispherical sector photoelectron spectrometer is described. The detector consists of a channel plate electron multiplier array, phosphor screen, silicon intensified target vidicon an optical multichannel analyzer control unit. Data collection rates are improved by more than two orders of magnitude over conventional single channel detectors.
A total current spectroscopy study of the growth of thin metal and semiconductor surface layers
Authors: Komolov S. A. , Chadderton L. T.
Published: December 2004

Experiments are described in which thin layers of silver and gold, and of cadmium sulphide and cadmium selenide, have been grown on metal substrates in ultra‐high vacuum. Total current spectroscopy (TCS) reveals details of the film formation processes until, finally, the spectrum obtained can be related to inelastic electron/electron scattering accompanied by interband transitions in the continuous overlayer. An analysis is presented which permits extraction of values for effective of values for effective mean free paths for different electron energies in the evaporated films.
Quantitative auger electron spectroscopy: Modulating the spectrometer
Authors: Seah M. P.
Published: December 2004

As part of an on‐going programme at the National Physical Laboratory on the quantification of surface spectroscopies, it is shown that, in using the modulation technique for quantitative Auger electron spectroscopic analysis in the differential mode, care must be taken in applying the modulation. With the complex electron spectrometers now being employed for combined X‐ray photoelectron and Auger spectroscopic work, error signals can be added into the spectra by several of the proposed systems of modulation. The error signals are analysed quantitatively and are shown to be important at energies below 200 eV. Similar error signals can be found in the case of the cylindrical mirror analyzer. To obtain the correct derivative spectrum care must be taken to modulate the whole electron spectrometer with AC levels in strict proportionality to the incremental DC changes appropriate to each of the electrodes.
A high pressure preparation lock for surface analysis
Authors: Polaschegg H. D. , Jungel A. , Schirk E.
Published: December 2004

A lock will be described that facilitates the preparation of samples in a small high pressure preparation chamber at pressures up to 30 bar (30 atm) and temperatures up to 800°C and the transport of the treated sample into the analysis chamber, which is under UHV, without reducing the pressure in the preparation chamber.
Surface characterization and adhesive bonding of stainless steels: I—the surface characterization of the steels
Authors: Gettings M. , Kinloch A. J.
Published: December 2004

In part I of this study, surfaces of three stainless steels have been characterized by scanning electron microscopy, electron probe microanalysis, Auger electron spectroscopy and X‐ray photoelectron spectroscopy. The surface characteristics, which were investigated before and after chemical etching, were found to be strongly dependent upon the method of steel manufacture. The environmental resistance of adhesive joints prepared using the steels depended upon the surface chemistry and roughness induced by the etching treatment. In part II the interface region of the three steels and silane‐based primer will be analysed and results correlated with durability studies.
Quantitative ESCA surface analysis applied to catalysts: Investigation of concentration gradients
Authors: Finster Joachim , Lorenz Petra , Meisel Armin
Published: December 2004

ESCA intensity measurements for quantitative surface analysis can give more information than the average composition in the surface region, e.g. for substances which possess a concentration gradient vertical to the surface. This concerns almost all samples which were subject to solid‐state surface reactions, among them frequently also supported catalysts. Enrichment factors Γ (that is, the measured intensity ratio compared with the ratio corresponding to the stoichiometric composition of the sample) are introduced and calculated for an exponential concentration–depth profile by convolution with the exponential attenuation law for photoelectrons. The two characteristic parameters in a two‐component system (surface concentration x0 and profile parameter n) can be determined independently only by the measurement of two or more Γ values for one sample, varying either the escape angle or the escape depth of photoelectrons. We used the latter method and measured besides the Ni 2p/Si 2p intensity ratios also the Ni 2p/Ni 3p intensity ratios of a series of NiO/SiO2 catalysts. The application of this kind of depth profiling to high surface area substances (an enrichment of one components in the outer region is necessarily connected with a depletion of the same component in deeper regions) complicates the deduced equations and needs further model considerations. We determined the characteristic parameters of the Ni concentration gradient in these catalysts and from them calculated the most important first layer composition. In combination with the analysis of ESCA line positions and shapes and in agreement with the results of other measurements, we were able to set up a model of the catalyst surface structure.
The study of radiation‐induced chemical damage at solid surfaces using photoelectron spectroscopy: A review
Authors: Copperthwaite Richard G.
Published: December 2004

After a short summary of the main processes occurring in an ionic solid during the absorption of radiation, the advantages of photoelectron spectroscopy in the study of the chemical consequences of such processes are summarized. A critical survey of the published work in this field is then undertaken, together with an assessment of future possibilities and applications.
X‐ray photoelectron study of thin evaporated films of Fe/Ni alloy
Authors: Nefedov V. I. , Pozdeyev P. P. , Dorfman V. F. , Pypkin B. N.
Published: December 2004

Thin evaporated films of Fe/Ni alloy on a SiO2 substrate were studied by means of ESCA. Depth‐composition profiles during ion sputtering and angular dependences of peak intensities upon take‐off angle of electrons were measured. The calibration curve for the ratio of intensities IFe 3p/INi 3p vs. bulk alloy composition was plotted. The uppermost layer of the film at the air/FeNi interface was enriched with Fe oxides. The next layer was slightly depleted of Fe atoms. At the FeNi/SiO2 interface the relative Fe and Ni content was the same as in the bulk of the film down to the layers of no more than 10 Å thickness. The approach to SiO2 during sputtering of the last thin layers of the film was accompanied by formation of charged Fe/Ni alloy islands on SiO2 which led to splitting of the Fe, Ni, Si, O and C lines. The width of the FeNi/SiO2 transition zone created by ion bombardment was about 35–50 Å for films of 100–200 Å thickness.
The energy dependence of the electron mean free path
Authors: Wagner C. D. , Davis L. E. , Riggs W. M.
Published: December 2004

Experiments providing multi‐point data on electron mean free paths vs. energy in pure materials have been reviewed for energies from 150 to 4000 eV. With the assumption that the simple equation λ=kEm can approximate the data, one obtains values of m between 0.53 and 0.80. Observations by ESCA of widely spaced photoelectron lines for Mg, Cu, Zn, Ga, Ge and As also lead to the conclusion that the exponent is considerably larger than 0.5, and is more likely in the range 0.65‐0.75.
ISS/SIMS characterization of mica surfaces
Authors: Baun W. L.
Published: December 2004

SIMS and ISS are used to characterize mica surfaces. The results on matching cleaved surfaces show that cleavage occurs along the potassium layer and the potassium ions are shared equally between the separated surfaces. A comparison of these freshly cleaved surfaces with original weathered surfaces shows large differences in the potassium content just at the surface. A mechanism of oxidation or chemisorption of water is suggested. Other ISS/SIMS data from treated mica surfaces show a high sensitivity for small chemical changes which take place on these surfaces. The experiments indicate that the ISS/SIMS technique should prove very useful for diffusion studies through thin films using mica surfaces.
Crater edge profling of Ni/Cr sandwich multilayer thin films by scanning Auger microscopy (sam)
Authors: Zalar A. , Hofmann S.
Published: December 2004

The principle of the technique of crater edge profiling is described as an alternative method to conventional sputter profiling. The predictions for the lateral composition profile assuming a Gaussian intensity distribution of the primary ion beam are tested for a multilayer sandwich structure of Ni/Cr layers of 11.5 nm single layer thicknesses after Ar+ ion sputtering through 20 layers and scanning Auger microscopy with a 10 µm diameter electron beam. Due to the small angle of 44.3″ of the slope of the crater formed by ion sputtering, a magnification factor (lateral variation/depth variation) of 5 × 103 is obtained.
XPS investigations of Cu(II) ion‐selective electrodes
Authors: Ebel M. F. , Tóth K. , Pólos L. , Pungor E.
Published: December 2004

The results of XPS investigations on Cu(II) ion‐selective electrodes are compared to redox sensitivity. A good correlation between surface composition and electrode function was obtained.
Shading at different take‐off angles in X‐ray photoelectron spectroscopy
Authors: Ebel Maria F. , Wernisch J.
Published: December 2004

Results of quantitative X‐ray photoelectron spectroscopic analysis are influenced by thin overlayers. Therefore, the reduced thickness of these layers has to be determined to allow a compensation to be made for this influence. An applicable method is based on the variation of the take‐off angle. In this paper the angular dependence of the photoelectron count rate caused by surface roughness is discussed. It is created mainly by X‐ray shading. As a consequence of these considerations the ultimate roughness depth can be given up to where the angular response of the count rate is not affected by X‐ray shading and thus the method of the variable take‐off angle can be applied.
XPS studies of a ferricyanide accelerated chromate paint pretreatment film on an aluminium surface
Authors: Treverton J. A. , Davies N. C.
Published: December 2004

An XPS analysis of a ferricyanide accelerated chromate paint pretreatment film found iron in the form of both a ferricyanide and a ferrocyanide ion. Chromium occurred in at least two different chemical environments, one of which was as a hydrated oxide. Aluminium and fluorine probably occurred together although the analysis was not conclusive in this respect. More positive evidence is available elsewhere. The behaviour of the elements on ion etching was consistent with a model of the film comprised mainly of hydrated chromium oxide microcrystallites covered with a monolayer of ferricyanides. Escape depth calculations and correlation of semiquantitative analysis with chemical and energy‐dispersive analyses of the film were also consistent with this model. Adsorption of ferricyanides on the surface of the precipitating particles of the growing film provides an explanation for their role as accelerators of film growth.
Determination of the centroid depths of shallow impurity profiles by X‐ray fluorescence spectrometry
Authors: Gries W. H. , Wybenga F. T.
Published: December 2004

A method is presented for the non‐destructive determination of centroid (mean) depths of shallow standard profiles (ion implanted, diffused, square) of dopant impurities in lighter materials by comparative X‐ray fluorescence measurement at different take‐off angles. The method is based on an analytical expression which links the ratio of two fluorescence signals to the distribution moments of the impurity profile. It is also shown how this method can be used for the identification of unknown standard profiles as well as for the determination of p–n junction depths in Si wafers.
Practical peak area measurements in X‐ray photoelectron spectroscopy
Authors: Bishop H. E.
Published: December 2004

An assessment of the reliability of peak area measurements using the simple linear background subtraction approach has been made by comparing the results obtained by a number of workers from a set of simulated spectra mixing the Fe 2p peaks from Fe metal and Fe2O3. The simulated spectra are generated from Gaussian peaks with a step background similar to that of Shirley, but modified to reproduce the sloping background on the low kinetic energy side of the peak. The results show that systematic errors in the total area of the Fe 2p peak may be as great as 40% using the workers best estimate of the background line. An alternative approach involving the areas of both 2p3/2 and 2p1/2 peaks reduces this error to 17%.
An asymmetric model for XPS analysis
Authors: Dunn William L. , Dunn Terry S.
Published: December 2004

The process of determining the overlapping peaks in complex X‐ray photoelectron spectra of polymer surfaces is posed mathematically as an inverse problem whose solution can be reduced to a standard least‐squares procedure. Various models can be generated by assuming specific forms for the distribution of effective binding energies corresponding to photoelectron kinetic energies and for the spreading kernel characteristic of the spectrometer. A particular generalized asymmetric model is developed for monochromatic X‐ray photoelectron spectroscopy of polymer surfaces based on physically meaningful electron energy loss characteristics and assuming the spreading kernel to possess both Gaussian and Lorentzian forms. Computer fits to experimental X‐ray photoelectron spectra indicate that the asymmetric model and curve‐fitting procedures employed offer an effective and flexible means for analyzing X‐ray photoelectron spectra.
Novel spectroscopic evidence on the nature of the depassivation of iron by halide ion
Authors: Cocke D. L. , Nilsson P. , Murphy O. J. , Bockris J. O'M.
Published: December 2004

XPS spectra of electrochemically formed passive films on Fe electrodes exposed to chloride ions, revealed chemical and physical changes in the films as a result of coming in contact with these ions. An enhanced C species signal with increasing exposure time to chloride ions was accounted for by increased chemical reactivity of the passive films toward hydrocarbons, due to the loss of hydroxyl groups and water, as well as to the creation of surface defect sites. An increasingly high binding energy O signal with increasing chloride ion exposure time was found to be due to physisorbed O species on an enlarged area, caused by a depolymerization or a pore breakdown mechanism in the passive layers. Chloride ion was not observed in the XPS spectra of the passive layers.
X‐ray photoelectron spectroscopic studies of carbon fibre surfaces. III—Industrially treated fibres and the effect of heat and exposure to oxygen
Authors: Proctor Andrew , Sherwood Peter M. A.
Published: December 2004

Carbon fibres, surface treated by an industrial process, were analysed by x‐ray photoelectron spectroscopy (XPS). The results allow the surface chemistry to be compared with that achieved by controlled laboratory methods. It is found that industrial treatment has less control over individual fibre surface treatment than in the laboratory treated fibres, and that the reproducibity of treatment varies with the treatment method. As the level of treatment is increased the spectra show an increase in the C/O and C/N surface functional groups. In contrast to the laboratory treated fibres there is no identifiable difference in the types or proportions of C/O groups with the amount of surface treatment, and the overall changes in the spectra are much less. The type and proportion of surface groups between treated and untreated fibres are different. C=O type groups appear to dominate in the treated fibre samples over O—O— type groups. Mass spectroscopic analysis associated with heat treatment can be very usefully combined with XPS analysis in the same apparatus as an aid to the understanding of complex industrially treated samples. Thus the effect of surface treatment can be effectively reversed by heat treatment to very high temperatures, with the regeneration of a fibre surface which resembles that of the untreated fibre surface. Exposure of the heated fibre after cooling to gaseous oxygen causes little change in the surface chemistry.
X‐ray photoelectron spectroscopy study of the surface composition of CoO‐MgO solid solutions
Authors: Cimino A. , Minelli G. , De Angelis B. A.
Published: December 2004

The surface composition of CoO–MgO solid solutions has been investigated by XPS. The samples (prepared at 1200°C in air) were checked to be homogeneous by X‐ray diffraction analysis and by lattice parameter measurements. The study utilized peaks at different kinetic energies: Co 2p, O 1s, Co 3s, Mg 2s, Co 3p, Mg 2p and the Auger transition Mg KLL. It was shown that the specimens have a surface composition slightly different from the bulk, because of the formation of surface magnesium hydroxide. No segregation of cobalt was found. The results have a bearing on the catalytic activity of oxide solid solutions.
Surface preparation for quantitative auger electron spectroscopy: Mechanical polishing and inert gas ion sputtering
Authors: Burke M. A. , Schreurs J. J.
Published: December 2004

This paper discusses the effect of surface preparation on surface composition as measured by Auger electron spectroscopy (AES). The problems of producing atomistically clean surfaces for calibration standards in quantitative AES analysis are illustrated by comparing the analyses of a series of copper–nickel binary alloys prepared by mechanical polishing and sputter cleaning with the compositions measured immediately after in situ fracture. Mechanical polishing results in surface enrichment by nickel for alloys of less than about 0.6 atomic fraction nickel, while alloys of greater than about 0.7 atomic fraction nickel exhibit surface enrichment by copper after mechanical polishing. Sputter cleaning results in a surface enrichment by nickel for all the alloy compositions considered (Xcu < 0.5). Additionally sputtering of the mechanically polished surfaces produces maxima in the surface nickel concentration, after short time sputtering, which coincide with the removal of the oxygen signals from the spectra. The results are discussed using a preferential sputtering model.
The effect of the grain structure of Al2O3 substrate on the solid state reaction with a layer of NiO: A comparative backscattering spectrometry study 1
Authors: De Roos G. , Fluit J. M. , De Wit J. H. W. , Geus J. W.
Published: December 2004

The solid state reaction of Al2O3NiO reaction couples was investigated by means of Rutherford backscattering spectrometry. NiO films on the alumina substrates were obtained by vapour–deposition of Ni and subsequent oxidation at 800°C in air. Substrates of about the same surface roughness, thus providing equal contact areas for the reaction couples, were used. The materials were characterized by scanning electron microscopy. In spite of the different structure and a grain size that varied within a factor of 10, of the Al2O3 materials, no obvious difference in the spectra based on the used reaction couples could be detected. Suggested substantial contribution to the reaction from surface diffusion and grain boundary diffusion along the substrate grain boundaries could therefore be rejected.
Quantitative evaluation of AES‐depth profiles of thin anodic oxide films (Ta2O5/Ta, Nb2O5/Nb)
Authors: Sanz J. M. , Hofmann S.
Published: December 2004

Thin films of anodically formed Ta2O5 and Nb2O5 on polycristalline Ta and Nb, respectively, are analysed with AES during sputtering with Ar+ ions at energies between 0.5 keV and 5 keV. A sputtering induced depletion of oxygen at the surface is observed in both oxides. The kinetics of this depletion and the steady‐state composition at the surface of the samples are studied as a function of the primary ion energy. The results are interpreted using a modification of the model of Ho et al. (1976) for the preferential sputtering of alloys. The thickness of the transient layer increases non‐linearly from 1.6 to 3.4 nm with increasing ion energy. Below 2 keV, the surface depletion of oxygen increases with decreasing ion energy and is constant above 2 keV up to 5 keV. The results are similar for both oxides. At 2 keV, the minimum measured width of the oxide/metal interface is 2 nm for Ta2O5/Ta and is about two times larger for Nb2O5/Nb. In both cases it increases with the square root of the ion energy and it is independent on the oxide layer thickness between 10 nm and 150 nm.
Small area x‐ray photoelectron spectroscopy
Authors: Yates K. , West R. H.
Published: December 2004

Small area XPS can be easily performed on spectrometers with hemispherical analysers, in which electron transfer from sample to analyser precedes retardation. Spatial resolutions of 250 μm diameter have been achieved on a commercial spectrometer and applied to the study of a mixed phase sulphide mineral. Determination of the position and size of the analysis area has been made by a combined SEM/SAM technique.
The spatial distribution of minority elements in carbon black
Authors: Fabish T. J.
Published: December 2004

X‐ray photoemission, elemental, and base neutralization measurements of minority element contents in carbon blacks are analysed self‐consistently within a model description of the powder to arrive at an estimation of the surface density of elements comprising the acidic surface groups for these materials. Element surface densities are found that are significantly smaller than those corresponding to concentrations of the minority elements wholly at the geometric surface of the carbon particle, but are generally greater than for a uniform bulk distribution. The intermediate values arise as a result of the concentration of oxygen into a shell occupying 60 to 90% of the total particle volume for the three carbon blacks considered.
Sulfur segregation to the metal oxide interface during the early stages in the oxidation of iron
Authors: Jennings Wayne D. , Chottiner Gary S. , Michal Gary M.
Published: December 2004

Iron (110) single crystals have been studied during the early stages of their oxidation at 800°C at an oxygen flux equivalent to a pressure of 2 × 10−5 Torr. Depth profiles using Auger electron spectroscopy (AES) determined that if sulfur was present on the metal surface before the oxidation then sulfur was present at the internal metal/oxide interface after a 20 minute oxidation. Oxidation of a clean surface resulted in very little sulfur at the internal metal/oxide interface after the same oxidation exposure even though sufficient time was available for sulfur to accumulate at that interface. The interpretation of the AES data was complicated by the non‐uniformity of the oxide growth. The oxide morphology was found to depend on the amount of sulfur on the free surface just prior to oxidation. A model for this growth was developed that was consistant with both the AES depth profiles and scanning electron microsopy (SEM) observations of the oxide surface morphology.
Use of secondary molecular ions in Cs‐SIMS elemental analysis
Authors: Gao Y.
Published: December 2004

We have investigated three factors in the use of secondary molecular ions in Cs‐SIMS elemental analysis: increase of ion yield, quantification and reduction of the matrix effect.
Analysis of semiconductors and insulators by high‐resolution electron energy loss spectroscopy—prospects for quantification
Authors: Pireaux J. J. , Thiry P. A. , Sporken R. , Caudano R.
Published: December 2004

High‐resolution electron energy loss spectroscopy (HREELS) is now widely known and recognized for its very significant contributions to the characterization of molecules adsorbed on well‐defined surfaces: many chemical surface reactions were understood successfully (adsorption sites, reaction scheme, time‐resolved experiments) through the analysis of electron‐induced vibrational spectra. Semiconductors and insulators form other classes of materials that contribute to vibrational spectra by intrinsic vibrations: compound semiconductors, and insulators present acoustic and optical phonons, i.e. collective lattice vibrations, whereas organic insulators (like polymers) offer numerous molecular groups to the vibrational excitation by the electron beam (extrinsic vibrations). Quantitative analysis of the surface of those materials rests on the understanding of the interaction mechanisms between monochromatized electrons and intrinsic or extrinsic vibrations.

Three scattering processes have been recognized to contribute to HREEL spectra: dipole interaction, impact scattering and resonance scattering. They have been characterized theoretically and experimentally through their dependence versus variation of the electron beam energy and/or of the scattering angular geometry.

Recent experiments have shown that the analysis of intrinsic phonons is very well understood for insulators. As a consequence, quantitative analysis of compound semiconductors is possible and brings additional information on the surface stoichiometry (of AlxGa1−xAs, for example) and on the doping level. For organic polymers, however, the excitation of molecular vibrations does not—up to now—appear to follow a simple scheme: all the scattering mechanisms (dipolar, impact and resonance) appear to play a significant role; a true quantification will be possible only through a systematic study of model compounds, and will require further theoretical treatments.
Depth profiling studies of oxidized alloy surfaces by glow discharge emission spectroscopy
Authors: Tsuji K. , Hirokawa K.
Published: December 2004

Depth profile analyses of elemental composition of Cu–Ni and Fe–Cr binary alloys oxidized in air and O2 gas mixtures were performed by glow discharge emission spectroscopy (GDS), adopting the cathode sputtering technique with a Grimm‐type glow lamp. The emission intensity ratio of Cu I 327.4/Ni I 352.5 for the oxidized Cu–Ni alloys is much larger than that for the non‐oxidized alloy at the beginning of the discharge, because of copper segregation on the surface of the oxidized Cu–Ni alloys. The composition depth profile analysis for oxidized Fe–Cr binary alloys indicates the presence of a stable chromium oxide formed on the surface, particularly a thinner oxide film for alloys having higher chromium concentration. The discharge current for the non‐oxidized alloy is almost constant during sputtering, but grows smaller for the oxidized alloys. This discharge behaviour must be considered in quantification.
An empirical electron spectrometer transmission function for applications in quantitative XPS
Authors: Hemminger Carol S. , Land Terry A. , Christie Alex , Hemminger John C.
Published: December 2004

The use of XPS data for accurate elemental quantitation requires that the transmission function of the electron spectrometer be known. Often, the dependence on electron kinetic energy (Ek) and spectrometer pass energy (Ea) are treated as separable functions. This is inadequate for the comparison of data taken with different pass energies. We have measured the variation of signal intensity as a function of Ea and Ek using the VG Escalab MK II spectrometer under constant analyzer energy conditions. Results from three independent laboratories on a variety of samples are in good agreement. The combined data have been used to develop an empirical formula that relates the signal intensity to the electron kinetic energy and spectrometer pass energy. The non‐separable relationship that we obtain is of the form

Relative sensitivity factors used for XPS quantitation depend on the instrument transmission function. It is not adequate to use an invariant table of factors for all analyser conditions, as is assumed by many XPS data systems. The above empirical formula leads to simple calculations of elemental sensitivity factors at different spectrometer pass energies. It will be demonstrated that this can facilitate comparison of small‐area and large‐area XPS data and quantitative analysis of complex materials where it is desirable to measure minor components at high pass energy.
A surface spectroscopic study of nitrogen ion‐implanted Ti and Ti–6Al–4V wear against UHMWPE
Authors: Lausmaa Jukka , Röstlund Tord , McKellop Harry
Published: December 2004

Nitrogen ion‐implanted pure Ti and Ti–6Al–4V alloy femoral heads that had been subjected to wear tests in a joint simulator were analysed by AES and XPS, in order to identify their surface composition and to estimate the amount of wear. XPS and AES survey spectra show that the surface of the ion‐implanted specimens consist of mainly a thin (∼10 nm) TiO2 surface oxide. Significant amounts of nitrogen in the form of Ti nitride are detected in spectra from the surface, both prior and after the wear tests. On some of the wear‐tested specimens, areas covered by a Ca‐dominated surface film of unidentified origin are observed. It is demonstrated how the overlapping Ti and N Auger peaks can be separated so that the nitrogen depth distribution can be obtained in depth profile measurements. The nitrogen depth profiles show that the thickness of the implantation layer varies considerably at different points on the samples. For the commercially pure Ti samples, the total amount of wear is significantly higher than for the Ti–6Al–4V samples. In none of the analysed samples had the ion‐implanted layer been worn off completely after the simulation.
Characterization of CuInSe2 thin films by XPS
Authors: Niemi E. , Stolt L.
Published: December 2004

The surface composition of CuInSe2 thin films, made by co‐evaporation of the elements, has been shown to be strongly dependent on the bulk composition of the films. This is explained by the presence of a secondary phase, most likely Cu2Se, on the surface of Cu‐rich films. The fast variation of the surface concentration is also found for films that, according to the equilibrium pseudobinary phase diagram (Cu2SeIn2Se3), should be single‐phase chalcopyrite. An explanation, suggesting the presence of a Cu‐rich compound also on the surface of films with a composition in the single phase regions, is proposed.

Surface atomic concentrations have been shown to be modified in CuInSe2 films by a 4.5 keV Ar+ sputter etch. Heating in vacuum at the film deposition temperature restores the surface atomic concentrations to an as‐deposited condition, with the exception of the selenium concentration. The missing selenium atoms are substituted by oxygen atoms still remaining in the film after sputtering and heating.
Back‐side SIMS profiles of dopant redistribution under silicide films
Authors: Jackman J. A. , Kular A. , Weaver L. , Mayer D. , Jackman T. E. , MacPherson C.
Published: December 2004

Samples suitable for sputter depth profiling of surface films from the substrate into the film have been produced by selective removal of most of the underlying silicon substrate. This procedure, which reduces problems due to collisional mixing and redeposition of sputtered material, was accomplished by the controlled growth of a boron‐rich etch‐stop layer using molecular beam epitaxy followed by selective chemical etching. The usefulness of this approach has been demonstrated by studying the redistribution of As during the growth of platinum and cobalt silicides with secondary ion mass spectrometry (SIMS).
Surface characterization of butyl methacrylate polymers by XPS and static SIMS
Authors: Castner David G. , Ratner Buddy D.
Published: December 2004

X‐ray photoelectron spectroscopy (XPS) and static secondary ion mass spectrometry (SIMS) were used to identify and quantify different isomeric butyl methacrylate polymers. The samples examined were normal‐, iso‐ and tert‐ butyl methacrylate (n‐, i‐ and t‐BuMA) homopolymers and two n/t‐BuMA random copolymers. XPS could differentiate the various BuMA polymers based on their valence band (VB) lineshapes. Resolution of the C1s spectra into four Gaussian peaks (hydrocarbon, β‐shifted hydrocarbon, ether and ester) produced similar peak widths and good agreement between the resolved peak areas and the polymer structure. Because of the C4 carbonium ions formed, static SIMS can distinguish the BuMA homopolymers by the increase in the m/z = 57+ signal (C4H9+) from n‐BuMA to i‐BuMA to t‐BuMA. For the n/t‐BuMA random copolymers, the amount of dehydrogenated C4 groups produced by static SIMS experiments (positive 55 and negative 71 ions) increased with increasing n‐Bu concentrations. Any one of several peak intensity ratios (positive 55/57 and 57/69 and negative 57/85 and 71/85) can be used to determine the percentage of n‐BuMA and t‐BuMA components present in an n/t‐BuMA copolymer. A combination of two different peak intensity ratios is required to distinguish the i‐BuMA polymer from an n/t‐BuMA copolymer. The clearest differentiation of the BuMAs was obtained by combining XPS VB and static SIMS results.
XPS analysis of silane coupling agents and silane‐treated E‐glass fibers
Authors: Pantano Carlo G. , Wittberg T. N.
Published: December 2004

The photelectron spectra of five different liquid silanes were measured. Their C 1s spectra and measured compositions were all consistent with the theoretical formula of these compounds. Subsequently, E‐glass fibers were exposed to dilute aqueous solutions of these silanes, and their adsorption on the fiber surfaces was observed. The high‐resolution C 1s spectra revealed the extent of hydrolysis. The thicknesses of the adsorbed layers were determined and were found to scale with the length of the organic functional group.