bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantitative analysis of complex Auger spectra by least‐squares fitting with prefiltering of spectra
Authors: Sekine T. , Mogami A. 
Published: May 2005

AbstractThe ‘filter‐fit’ method, which was originally developed for the analysis of energy dispersive x‐ray data, has been applied to the quantitative analysis of Auger spectra for the first time. It is a digital peak deconvolution technique in the presence of the continuum background using least‐squares fitting calculations, including the prefiltering of spectra. To evaluate this method, composite‐known spectra digitally composed of Cr, O and Ni standard spectra were prepared. For the deconvolution of Cr and O peaks under the influence of the Ni peak tail, the present method showed remarkable advantage over the conventional least‐squares fitting without prefiltering. As a digital filter for prefiltering, derivative filters of different orders and ‘top‐hat’ filter were examined. In derivative filters, it was found that there is an optimum order in the balance of advantage of suppressing the background and disadvantage of losing peak intensity. The ‘top‐hat’ filter is a very practical filter in both background suppression and noise attenuation.
Quantitative AES depth profiling of very thin overlayers
Authors: Sanz J. M. , Hofmann S. 
Published: May 2005

AbstractA model calculation is proposed which quantitatively evaluates measured AES sputtering profiles of very thin overlayers in terms of the original elemental depth distribution. The model is based on the sequential layer sputtering model, including the escape depth of the Auger electrons. A proposal for the incorporation of a site dependent sputtering yield and of preferential sputtering effects is presented and the limitations and capabilities are discussed. Applications to experimental data are shown for oxide films on tantalum, for an oxidefilm on a NiCr20 alloy and for a passive film on FeCr18Ni9.
Spatial chemical analysis of polymer laminates and conducting organic films using SIMS
Authors: deVries J. E. , Holubka J. W. , Prater T. J. , Kaberline S. L. , Schuetzle D. , McIntyre N. S. , Chauvin W. 
Published: May 2005

AbstractSecondary ion mass spectrometry (SIMS) has been used to generate images of polymeric materials including a polymer laminate and metal‐chelated organic materials cured on Teflon substrates. Metal‐chelation facilitated the imaging of organic materials by monitoring of the metallic tag. Incorporation of the metal into the organic complex made the sample conductive therefore circumventing charging difficulties normally associated with SIMS analysis of organics. Each layer of the polymer laminate could be easily identified by monitoring molecular fragment ions that were distinctive for each polymer type. Images were acquired at a resolution of approximately 5–10 μm.
Quantitative non‐destructive in‐depth composition information from XPS
Authors: Tougaard S. 
Published: May 2005

AbstractThe XPS peak shape from inhomogeneous transition metals is studied theoretically under variation of the path length R travelled by the photoelectron in the solid, the XPS peak energy Ep, and the particular metal M. The variation in peak shape is characterized by a single parameter D = Ap/B which is the ratio of the peak area to the increase in background signal 30 eV below the peak energy. It is found that D is a strong function of R, a moderate function of Ep and to first order independent of M. This gives theoretical support to the idea suggested previously of using D for fast non‐destructive extraction of in‐depth composition information. To a good approximation we have D(R,Ep) = (425+Ep) × R, with Ep in eV, R in Å and D(R,Ep) in eV. The practical use of this function in the analysis of experimental data is discussed.
Auger electron spectroscopy depth profiling during sample rotation
Authors: Zalar A. 
Published: May 2005

AbstractThere are many factors that affect depth resolution of AES compositional depth profiles; quite often, it is degraded mostly by the sample surface roughness. We differentiate between the initial roughness of the sample surface and the roughness induced by ion sputtering during depth profiling. The influence of the ion beam incidence angle and of the ion energy on the depth resolution of multilayer Cr/Ni thin film structures was initially investigated on the samples that were stationary during AES depth profiling. The sputtering induced surface topography was investigated by transmission electron microscopy. In order to diminish topographical effects, we applied sample rotation during AES depth profiling. The sample holder of a commercial AES instrument was equipped with a mechanism that enabled sample rotation (1 rpm) during the simultaneous ion sputtering and AES analysis. The influence of sample rotation on depth resolution was studied on multilayer Cr/Ni thin film structures deposited on smooth substrate and on SiO2/Si samples. In all the cases studied, sample rotation during depth profiling improved depth resolution. This improvement was in some cases surprisingly large, whereas in other cases it was less substantial, depending on the type of sample and its original surface topography, on the ion beam incidence angle, on the ion beam energy, and on the sputer depth. The main reasons for improved depth resolution resulting from sample rotation during depth profiling are the decrease of the angular dependence of the sputtering yield for variously oriented microplanes with respect to the ion beam direction, and the decrease of the roughness induced during ion sputtering.
Wetting and spreading of liquid metals: the rôle of surface composition
Authors: Smith Graham C. , Lea Colin 
Published: May 2005

AbstractQuantitative measurements of the surface compositional changes which occur during the wetting of copper substrates in vacuum by liquid SnPb solder alloys have been made in situ, by Auger electron spectroscopy. Five different spatial regions associated with the wetting front have been identified. Away from the spreading front, the liquid solder shows a surface enhancement of lead. Approaching the front, adjacent bands of Cu3Sn intermetallic compound, and tin‐depleted liquid occur, both of width ∼ 20 μm. The lead‐enriched surface of the solder extends over these two regions, and out over the copper to form approximately 50% monolayer ‘halo’ of ∼ 80 μm width. Beyond the halo, in the fifth region, very small amounts of tin and lead were detected. The lead halo forms rapidly by surface diffusion, and precedes wetting. In the absence of other limitations, it is the reduction of the copper substrate surface energy by the lead halo that restricts the spread of the molten alloy. Intermetallic compound formation is relatively slow and only takes place once spreading has ceased and a quasiequilibrium reached.
Depth profiling of carbonaceous films, produced in situ in the Tokamak TEXTOR
Authors: Tschersich K. G. , Littmark U. , Fleischhauer H. P. 
Published: May 2005

AbstractSamples of Si, Ni and Cr exposed to an in situ ‘carbonization’ in the Tokamak TEXTOR have been investigated. Depth profiles have been measured by argon ion sputter etching and AES. From the AES energy spectra (direct counting), the relative AES signals (peak to background ratios) have been derived by properly fitting the background and the peaks. The depth profiles are discussed in light of a ballistic‐mixing model for sputter etching and a standard exponential Auger escape probability.
SIMS analysis of AlxGa1–xas/gaas layered structures grown by metal‐organic vapour phase Epitaxy
Authors: Boudewijn P. R. , Leys M. R. , Roozeboom F. 
Published: May 2005

AbstractFor AlxGa1‐xAs/GaAs layered structures, grown by MOVPE, abrupt interfaces in the order of one atomic distance were observed. These structures are well suited to serve as test samples for studying the influence of bombardment conditions on the quality of SIMS depth profiles. The results of such a study are presented and it is shown that depth profiles can be obtained with a depth resolution of about 25 Å. It was found that beyond the interface secondary ion signals decrease exponentially; from the variation of the slope of this exponential decay as a function of primary ion energy it can be concluded that depth resolution is determined by a purely collisional mixing process. From this type of data we can derive a minimal layer thickness in AlxGa1‐xAs/GaAs quantum well structures for which quantitative SIMS analysis of the Al content is possible.
The application of secondary Ion mass spectrometry to surface analysis of semiconductor substrates and devices
Authors: Brown A. , van den Berg J. A. , Vickerman J. C. 
Published: May 2005

AbstractThe application of static, dynamic and imaging SIMS to semiconductor starting materials and devices is discussed. Static SIMS is used to examine the effect of various chemical preparation methods on the surface of the III‐V compounds InAs, InP and GaAs prior to epitaxial growth of device structures. Dynamic SIMS profiles from a superlattice structure involving alternative GaAlAs ‐ GaAs layers are presented along with an examination of the factors affecting depth resolution for low‐dimensional devices. Finally the importance of imaging or scanning SIMS for chemical mapping and microanalysis of final device structures is discussed.
Application of GDOS (glow discharge optical spectroscopy) and SIMS to the analysis of surface corrosion products on stainless steel after exposure to liquid alkali metals
Authors: Barker Marten G. , Schreinlechner Inge E. 
Published: May 2005

AbstractCorrosion of steels by liquid alkali metals involves the transfer of non metals, such as C, N or O, from solution in the alkali metal to the surface of the steel. Surface corrosion products may then be formed. With oxygen in sodium these products may be ternary oxides, with nitrogen in lithium the ternary nitride Li9CrN5 is formed and with carbon binary carbides are formed in both alkalies. Along with the surface corrosion products, element depletions and carbon or nitrogen diffusion profiles are created. The analyses of thin corrosion product layers and the determination of the concentration profiles of carbon and nitrogen are important requirements for the understanding of the corrosion process. Lithium penetration into steel is also a major problem in lithium corrosion. Lithium is extremely difficult to determine by conventional analytical methods, due to its low atomic number. In this paper the use of glow discharge optical spectroscopy (GDOS) and SIMS for the study of surface corrosion products, is described, together with a quantitative determination of the carbon‐depth profile in type 316 steel exposed to liquid sodium.
ESCA study of the oxidation of a nickel–molybdenum alloy
Authors: Marcus P. , Olefjord I. 
Published: May 2005

AbstractThe surface composition of Ni–6at% Mo (110) alloy was analysed by ESCA after surface preparation treatments and after oxidation at 25°C and 500°C (p = 10−4 Torr). Ion etching causes a marked enrichment of molybdenum on the surface. After annealing at 500°, the concentration of segregated molybdenum is ˜25%. At 800°C there is no segregation of the metal elements, but sulphur segregates to the surface. Oxidation at 25°C gives a thin oxide layer (5–6 Å) with a composition which reflects the composition of the initial surface, so that the oxidation of a surface enriched with molybdenum gives a molybdenum‐rich oxide. Oxidation at 500°C gives a molybdenum‐enriched oxide. The Mo concentration of the oxide is 12%, i.e. twice that in the bulk. The lateral growth of oxide islands seems to be already complete after a very short oxidation time (2 min) and then a parabolic growth of the oxide layer is observed. The chemical shifts of Ni2+ (2p3/2) and Mo6+ (3d5/2) in the oxide formed on the alloy are respectively 2.1 eV and 4.2 eV, while they are 1.6 eV for NiO and 4.8 eV for MoO3. Adsorbed sulphur has a marked influence on the oxidation. The oxide growth (also parabolic) is faster in the presence of sulphur at 500°C. The oxide film grows on top of the sulphur layer.
A high‐performance low‐cost computer interface for AES/XPS
Authors: Tomich D. H. , Grazulis L. , Grant J. T. 
Published: May 2005

AbstractAn Auger/XPS system has been automated using a mircocomputer. Some considerations in the design of the interface which could be used for a variety of spectroscopies will be presented and should be of general interest. The spectrometer used in this work was a Perkin–Elmer Physical Electronics Model 550 SAM/XPS. The computer used was a Zenith Z‐100 but the interface was designed for use with any microcomputer having two parallel I/O ports. Hardware details will be discussed with emphasis on the versatility, efficiency, and cost. The sweep control for the electron energy analyzer utilizes two 12 bit DAC's, one for the starting energy and another for the energy sweep range, thereby allowing 12 bits of resolution in both the sweep and offset. The software has been written in Microsoft FORTRAN, a subset of FORTRAN 77. The versatility of this system is illustrated with XPS data from Ag and a high kinetic energy backscattered primary.
The space within a profile
Authors: Zipin Richard B. 
Published: May 2005

AbstractA characteristic of surface texture which is often overlooked by engineers who specify surfaces, but which could be of great importance to them in the tribological analysis of surface profiles, is the space contained within the profile. There are two related parameters which express this characteristic, namely the volume of material in the profile hills, and the volume of empty space in the profile valleys. The former is the volume of material above a specified level within the profile and the latter is the volume of empty space below a specified level, both per unit area of surface. They are measured by the area bounded by a line at the particular level of interest and the profile curve itself, either above or below the line at the level of interest respectively, per unit length along the profile. When they are evaluated at the mean line of the surface profile, their sum is equal to the roughness average which is the most common surface texture parameter specified for engineering surfaces.These parameters are of significance to tribologists since the volume of material in the surface hills is clearly related to the load carrying capacity and the wear resistance of a surface, while the volume of empty space in the valleys relates to the ability of the surface to retain lubricant and to store debris, all of which are important in applications where contact between surfaces is involved.The two parameters are studied for deterministic and random surface profiles and their digital implementation is derived. Applications of the analysis presented are discussed.
Electron yields and escape depths from Kapton and Teflon
Authors: Yang Kai‐Yueh , Hoffman R. W. 
Published: May 2005

AbstractSecondary electron emission (SEE) characteristics, i.e., SEE yield maximum, the electron energy corresponding to the maximum yield, Emax, and crossover energies at which the SEE yield is unity, as a function of angle of incidence were determined for Kapton and Teflon. Photoelectron yield as a function of angle of incidence from Kapton were also determined. Secondary electron escape depth and photoelectron escape depth from Kapton were calcuated from the experimental data.Pulse beam techniques were used to reduce surface charging problems. Three μsec pulses of electrons were used in SEE experiments, and 100 msec to 1 sec pulses were used in photoemission experiments. The maximum yield of Kapton increases from 1.7 at normal incidence to 3.0 at 80° angle of incidence, Emax increases from 280 eV to 620 eV. The maximum yield of Teflon increases from 2.4 at normal incidence to 3.1 at 80° angle of incidence. The secondary electron escape depth in Kapton was calculated t be 55 ± 5 Å. Photoelectrons excited by 21 eV photons have a 87 ± 30 Å escape depth in Kapton.
In situ interface analysis by ion backscattering/channeling technique using a thin window cell
Authors: Padmanabhan K. R. , Bhowmick S. , Hua Zhang Zu 
Published: May 2005

AbstractIn situ analysis of solid–liquid and solid–gas interfaces by high energy ion backscattering/channeling technique have been investigated. Using thin single crystal windows like that of Si in a specially constructed cell, the backscattered yield and the channeling minimum yield have been utilized to obtain in situ information on solid–gas and solid–liquid interfaces. Examples in the application of this technique to investigate the in situ etching damage at the interface in the dry etching of Si have been given. It is found that XeF2 etching of Si crystal offers a good surface which is relatively free from any visible damage within the limitation of the sensitivity of the RBS analysis. The evidence of an epitaxially grown Cu layer on Si from CuSO4 solution in the thin window cell has been given. These experimental results demonstrate the potential application of this technique in the field of catalysis and electrochemistry.
Ion beam mixing of Pt with René N4 alloy
Authors: Srinivasan V. , Bhattacharya R. S. 
Published: May 2005

AbstractIon mixing was studied in Pt‐René N4 alloy system. The substrate, René N4, is a nickel‐base superalloy with about 66% of ordered γ′ precipitates by volume. The average precipitate size is approximately 0.42 μm. Mixing was accomplished by 1 MeV Pt+ ions at two different doses and followed by Rutherford back scattering and Auger sputter profiling. Mixing was significantly slower in this system than it was in Pt/Ni binary alloy suggesting a possible strong influence of alloy chemistry, microstructure or intermediate impurity layer on the mixing process.
High resolution electron microscopy of surfaces and surface reactions
Authors: Smith David J. , Bovin J. O. , Bursill L. A. , Petford‐Long A. K. , Ye H. Q. 
Published: May 2005

AbstractA 400 kV high‐resolution electron microscope has been used in the surface profile imaging mode to observe surfaces and surface reactions directly in real time. The processes studied include: the formation of surface oxides on Pd and Ag and on In‐compound semiconductors; surface reduction and metallization, diffusion and accretion on oxide surfaces; and structural rearrangements in small metal particles. It is concluded that the technique can provide unique information about surface phenomena.
Application of cross‐sectional transmission electron microscopy in the characterization of ion beam processed materials surfaces
Authors: Rai A. K. , Bhattacharya R. S. , Pronko P. P. , Tai‐il‐Mah  
Published: May 2005

AbstractIon‐beam‐mixing‐induced amorphization of NiTi bilayered thin film and the amorphization of α‐SiC through ion bombardment have been studied by employing cross‐sectional transmission electron microscopy techniques. Rutherford backscattering analysis was employed to monitor the mixing of NiTi bilayer as a function of dose (3 × 1015−2 × 1016 ions cm−2) of 1 MeV Au+ ions. It has been observed that amorphization starts at the interface as the mixing proceeds. Formation of a buried amorphous layer was obtained in α‐SiC by ion bombardment with 2.5 MeV Ni+ at a dose of 1 × 1016 ions cm−2. Double energy implants (1 MeV Ni+, 1 × 1016 ions cm−2+2 MeV Ni+, 1 × 1016 ions cm−2) were employed to obtain 1.8 μm thick continuous amorphous layer on the surface of α‐SiC. Also, in the present investigation, it has been shown that α‐SiC pieces with amorphous surface layers joined better than those with as received crystalline surface layers.
Investigation of resin–substrate interactions: An IETS study of phenol‐ and cresol‐ formaldehyde model compounds
Authors: Brown N. M. D. , Meenan B. J. , Affrossman S. , Pethrick R. A. , Thomson B. 
Published: May 2005

AbstractThe IET spectra of a number of phenol‐like, cresol‐like and methylolated ‘phenols’ are reported. These molecules are used as models of certain of the structural units found in a typical Novolac phenol–formaldehyde resin system. It is found that these poly‐phenolic molecules adsorb an aluminium oxide in predominantly the form of phenolate anions. In the case of those molecules in which the phenolate is associated with ortho‐methylol groups a site‐specific adsorption and a local near‐perpendicular alignment at the oxide surface is proposed. The spectra found also show that the formation of chemisorbed phenolate anion(s) occurs with adsorbate deprotonation and reaction with surface hydroxyl groups, with this latter process forming water which is then desorbed. The ease of this reaction suggests that the reverse process may be related to the loss of adhesion when a joint structure is exposed to water vapour.
Imaging XPS—a new technique. 2—Experimental verification
Authors: Gurker N. , Ebel M. F. , Ebel H. , Mantler M. , Hedrich H. , Schön P. 
Published: May 2005

AbstractThe XPS image is obtained by the dissection of the surface area of interest into a series of adjacent narrow strips. The width of the entrance slit system of the energy analyzer gives the strip width and a translational movement of the specimen makes it possible to investigate the total number of strips step by step. By means of the double focusing properties of the spherical analyzer the energy spectrum from each point (spot) of the strip area under observation is available on the detector focal plane. Specific photoelectron lines are selected by a suitable choice of the sphere voltages. A position sensitive electron detector together with a computer is used to collect and store these spectra simultaneously in the course of one measurement. The net count rate is evaluated afterwards. Each spot of the strip is represented by its corresponding value of the net count rate and the series of values is stored in a computer memory. At the end of collection of all the strip information the image is put together strip by strip. To date a resolution of 0.3 mm has been realised and the time of data collection for an area of 10 × 10 mm2 is about one hour. The corresponding time of measurement with our imaging method is just a few minutes as one needs only the elemental distribution of an element along a single line as in an electron micronalyzer with a line scan.
Surface segregation and preferential sputtering in CoNi alloys: Computer simulation of Auger spectra
Authors: Hajcsar E. E. , Dawson P. T. , Smeltzer W. W. 
Published: May 2005

AbstractThe phenomena of surface segregation and preferential sputtering have been investigated in the CoNi alloy system where previous results have been contradictory. Six alloys covering the whole solid solution range were annealed at 853 K and quenched to give equilibrium segregated surfaces. Computer simulation methods were employed to analyze spectra in both energy windows significant to the system and results are reported with explanations of previous discrepancies. Shown is the fact that Ni both preferentially sputters and segregates over the whole composition range. The segregation is only truly obvious in low energy (M2,3M4,5M4,5 transisitions) spectra as it is a monolayer phenomenon and higher energy peaks are not surface sensitive enough.
A review of the surface tension of silicon and its binary alloys with reference to Marangoni flow
Authors: Keene B. J. 
Published: May 2005

AbstractHigh quality single crystals of silicon required by the electronics industry are produced in bulk by crystal‐growth‐from‐the‐melt techniques. Temperature and concentration gradients at the free surface of the melt will give rise to surface tension‐driven flow (Marangoni flow), which, if sufficiently large, can lead to crystal defects in the end‐product. The relevance of the liquid surface properties to Marangoni flow is discussed. Published data for the surface tension of silicon and its binary alloys have been collated. Analysis of the data suggests that many of the results quoted for the surface tension of silicon may refer to material contaminated with oxygen. None of the solutes in the binary melts exhibits significant surface‐activity in silicon. Potentially important systems, for which there are no data, have been identified.