bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structural and electrical properties of thin d.c. magnetron‐sputtered gold films deposited on float glass
Authors: Markert Christian , Lützenkirchen‐Hecht Dirk , Frahm Ronald 
Published: March 2006

AbstractThe combination of in situ electrical resistivity measurements and ex situ tapping‐mode atomic force microscopy (AFM) in air was used to study the surface topography and the electrical properties of thin d.c. magnetron‐sputtered gold films on float glass substrates. In particular, the influence of the deposition temperature and a subsequent isochronous annealing process on the electrical resistivity and the surface structure of the polycrystalline gold films were analysed. The results show that a minimum surface roughness of about 0.4 nm was achieved for a deposition temperature of about 350 K. After the annealing process, an increase of the surface roughness and the lateral crystallite size was observed in general, suggesting that the measured decrease in resistivity during annealing is not related to a smoothing of the surface, but to the decrease of the grain‐boundary scattering of the conduction electrons. Assuming that the annealing processes are diffusion‐limited reactions, we calculated the corresponding activation energies from the irreversible branch of the annealing curves, yielding values of about 0.6–1.0 eV, which also correspond to grain‐boundary diffusion. Copyright © 2006 John Wiley & Sons, Ltd.
ZnO thin films on aluminized steel by spray pyrolysis
Authors: López Ibáñez R. , Romero R. , Martín F. , Ramos‐Barrado J. R. , Leinen D. 
Published: March 2006

AbstractSpray pyrolysis is a low‐cost technique and results in minimal waste production when using adequate precursors. The process allows the coating of large surfaces and is appropriate for adaptation into an industrial production line. The aim of this work has been to obtain, by spray pyrolysis, thin and compact ZnO films on 30 × 40 cm galvanized steel sheets heated by high frequency magnetic induction and using zinc acetate precursor in aqueous spray solution. The work includes a study of optimized deposition conditions (substrate temperature, precursor solution concentration, flow rate and spray time) controlled ex situ by SEM, XPS, XRD and UV‐Vis‐NIR and FTIR diffuse reflectance spectroscopy, in order to obtain an effective barrier coating with low thermal emittance when the steel is used as a base material for solar thermal devices. Our results show improved anti‐corrosion performance when the substrate coverage is guaranteed, substrate temperature and deposition time being the main factors to accomplish the optical requirements of the ZnO‐coated galvanized steel. Copyright © 2006 John Wiley & Sons, Ltd.
Grafting of bifunctional fluorinated polyether molecules on metallic surfaces: application to the protection of electrical contacts
Authors: Noël S. , Lécaudé N. , Alamarguy D. 
Published: March 2006

AbstractProtection of metallic surfaces against corrosion and wear is of high economical interest, particularly in the field of electrical contacts. New types of bifunctional fluorinated polyethers have been synthesised in order to elaborate innovative protective coatings. The films were elaborated by dipping the metallic substrates in solutions comprising the molecules and a perfluorinated solvent. Two linear perfluorinated polyethers (PFPE) were studied, having either highly or partially fluorinated thiol end groups.Galvanic gold samples were coated by dipping for a very short time in order to simulate an industrial process. The characterisation of the formed layers was performed by XPS. It was shown that despite the very short dipping time, the sulphur atoms of the thiol end groups were grafted to the gold surface. Different grafting kinetics were observed for the two types of molecules, which explains different behaviours were recorded during friction experiments. These molecules offer very promising properties in the field of surface modification and protection. Copyright © 2006 John Wiley & Sons, Ltd.
Comparative study of the interfacial characteristics of sputter‐deposited HfO2 on native SiO2/Si (100) using in situ XPS, AES and GIXR
Authors: Tan Ruiqin , Azuma Yasushi , Kojima Isao 
Published: March 2006

AbstractThe HfO2/SiO2/Si, Hf/SiO2/Si and HfO2/Hf/SiO2/Si interfaces formed by rf magnetron sputtering deposition were comparatively investigated using in situ high resolution X‐ray photoelectron spectroscopy, auger depth profiling and grazing incident X‐ray reflectivity (GIXR). The reactive deposition of HfO2 directly on native SiO2/Si (100) leads to an extraordinarily thick Si‐rich interface of about 3.33 nm, which will limit the capacitance of high‐κ films. To suppress the growth of the unexpected interface, it has been found that the pre‐deposition of Hf (about 1 nm) is effective. The Hf radicals reduce SiO2 to metallic Si to form HfO2 and partly result in HfSix. After subsequent reactive deposition of HfO2 on Hf/SiO2/Si stacks, the Hf‐rich silicates interlayer is as thin as 1.88 nm, calculated as an equivalent thickness of SiO2. All the XPS, AES depth profiling and GIXR results show a good coincidence with each other. Copyright © 2006 John Wiley & Sons, Ltd.
XPS investigation of CoOx‐based MRISiC structures for hydrocarbon gas sensing
Authors: Comini E. , Cusmà A. , Kaciulis S. , Kandasamy S. , Padeletti G. , Pandolfi L. , Sberveglieri G. , Trinchi A. , Wlodarski W. 
Published: March 2006

AbstractSensors based on metal–reactive insulator–silicon carbide (MRISiC) devices are widely employed for monitoring industrial processes because of their resistance to harsh and high‐temperature environments. MRISiC structures composed of the films of Pt and cobalt oxide (CoOx) were fabricated and investigated. The films of Pt and CoOx were deposited on SiC substrates by using r.f. magnetron sputtering. The depth profiles of their chemical composition were studied by XPS combined with cyclic Ar+ sputtering. The surface morphology was investigated by AFM. XPS analysis of the Co 2p peaks and shake‐up satellites revealed the presence of the mixed‐valency oxide Co3O4 on the sample surface, while deeper in the film only stoichiometric CoO was present. The platinum film deposited on the top of cobalt oxide was found to be metallic and uniform enough to inhibit further oxidation of Co2+. The hydrocarbon (propene) gas sensing performance of the Pt/CoOx/SiC devices was studied. Copyright © 2006 John Wiley & Sons, Ltd.
Electrostatic electron spectrometer based on two cylinders without axial symmetry
Authors: Varga D. , Tőkési K. 
Published: March 2006

AbstractThe calculated electron‐optical properties of a mirror type electrostatic electron spectrometer are presented. The analyzer consists of two cylinders without axial symmetry. We show that a spectrometer having such a construction has second‐order focusing properties with remarkable dispersion. Copyright © 2006 John Wiley & Sons, Ltd.
X‐ray photoelectron spectroscopy study of energy‐band alignments of Lu2O3 on Ge
Authors: Perego M. , Seguini G. , Scarel G. , Fanciulli M. 
Published: March 2006

AbstractX‐ray photoelectron spectroscopy (XPS) was used to investigate the band alignment of lutetium oxide films with a germanium substrate. Lu2O3 films were grown on Ge (100) by atomic layer deposition. The conduction ‐ (CBO) and valence ‐ (VBO) band offsets of the Lu2O3/Ge heterojunction were determined to be 2.2 ± 0.1 and 2.9 ± 0.1 eV respectively. Internal photoemission measurements performed on metal‐oxide‐semiconductor devices gave a CBO of 2.1 ± 0.1 eV and a VBO of 3.0 eV, in excellent agreement, within the experimental error, with the values obtained by XPS. Copyright © 2006 John Wiley & Sons, Ltd.
In‐depth composition study of zirconia‐coated steel sheet by XPS
Authors: López R. , Romero R. , Martín F. , Ramos‐Barrado J. R. , Leinen D. 
Published: March 2006

AbstractZirconia was deposited by spray pyrolysis on large‐area aluminized steel sheets using two different types of heat sources: infrared radiation or white light. XPS in‐depth composition study has shown that the carbon concentration is 4 at.% when using white light but 15 at.% when using infrared radiation. This carbon is found as zirconium carbide, formed as a diluted phase in the zirconia coatings. In the case of using infrared radiation, reflectance spectroscopy revealed a partial degradation of the optical properties of the coatings due to an incomplete pyrolysis of the precursor. These findings are of direct interest for unglazed solar façade elements made of steel, in which the zirconia coating will act as a barrier layer against the degradation of the steel sheet during long‐term outdoor exposure. Copyright © 2006 John Wiley & Sons, Ltd.
XPS characterization of anodic oxides grown on biocompatible Ti–50Zr alloy in different acid electrolytes
Authors: Ferreira E. A. , Oliveira N. T. C. , Biaggio S. R. , Nascente P. A. P. , Rocha‐Filho R. C. , Bocchi N. 
Published: March 2006

AbstractIn this work, X‐ray photoelectron spectroscopy (XPS) analyses were performed in order to identify the surface composition of oxide films electrochemically grown on Ti–50Zr and to verify whether anions from the electrolytes (H3PO4, H2SO4, and CH3SO3H) were incorporated into these oxide films. For all three electrolytes, an oxide film surface enrichment in Ti was observed, being more pronounced in the case of the H3PO4 solution. After sputtering, the alloy oxide film obtained in the H2SO4 solution presented the highest deviation from the equiatomic stoichiometry. Phosphorus‐containing species were incorporated into the oxide film grown in the H3PO4 solution, but no sulfur‐containing species were detected in the films grown in the H2SO4 and CH3SO3 H solutions. Copyright © 2006 John Wiley & Sons, Ltd.
Correlation between optical properties and electronic parameters for mixed oxide thin films
Authors: Gracia F. , Yubero F. , Espinos J. P. , Holgado J. P. , González‐Elipe A. R. , Girardeau T. 
Published: March 2006

AbstractSixTi1−xO2 optical thin films with variable compositions varying from pure TiO2 to pure SiO2 have been prepared by ion beam induced chemical vapor deposition (IBICVD). It has been found that the refractive index of the films increases with the content of titanium, from about 1.46 to 2.35. Band gap energies have been determined by optical methods and reflection electron energy loss spectroscopy (REELS), both techniques showing a similar evolution consisting of a sharp decay from the value of pure SiO2 to the samples with 2% Ti and then a smoother decrease up to the value of pure TiO2 (i.e. 3.2 eV). Changes also occur in the value of the binding and kinetic energies (KEs) of the Ti and Si photoemission and auger peaks, respectively, as measured by X‐ray photoelectron spectroscopy (XPS). The refractive indices of the films have been compared with the value of the auger parameters of Ti and Si. A good correlation exists between these two parameters as a function of the titanium content. This confirms that both depend on the polarizability of the medium and shows that XPS can be used for the assessment of optical properties of complex oxide materials. Copyright © 2006 John Wiley & Sons, Ltd.
Visualization of early stages of corrosion processes by a chemographic method
Authors: Yelizarov M. A. 
Published: March 2006

AbstractCorrosion of duralumin was studied in sandy soil conditions with different moisture and ion concentrations. The influence of these factors on initial (the first hours) corrosion stages was visualized by a chemographic method in which a film works as an indicator of the volatile products released during the electrode process, which may transform silver to the metallic state. Atomic hydrogen acts as such a product during metal corrosion. As a result, the pattern of optical density in a chemogram maps the corrosion activity of a specimen surface. The soil condition was checked by using its conductance. Two mechanisms of conductance were differentiated and analysed in terms of the percolation theory for low‐moisture soil (<1% mass moisture) and high‐moisture soil. It was found that the ion concentration in solution has no practical influence on conductance at low moisture. Traced reactions of duralumin corrosion show that this process is different in low‐ and high‐moisture soils. Pitting corrosion was visualized at the very beginning, with pits being located immediately and precisely on the surface of model specimens. Patterns of duralumin corrosion were traced in cases when cathode protection was applied and when a duralumin specimen worked as a sacrificial anode. The results of this research can be used to develop electrochemical corrosion protection systems for underground metal constructions. Copyright © 2006 John Wiley & Sons, Ltd.
Quantification and IMFP determination of multilayer Langmuir–Blodgett films by AFM and XPS measurements
Authors: Sato Masahide , Tsukamoto Naoto , Shiratori Tsubasa , Furusawa Takeshi , Suzuki Noboru , Tougaard Sven 
Published: March 2006

AbstractXPS spectra of cadmium arachidate Langmuir–Blodgett (LB) multilayer films have been investigated by quantitative peak shape and intensity analysis (the Tougaard method). The structure and film thickness of cadmium arachidate multilayer (1–21 layers) LB films on silicon wafers were observed by atomic force microscopy (AFM). The monolayer and bilayer thickness of cadmium arachidate LB film was determined to be 2.3 and 5.5 nm from AFM images of partially scratched multilayer LB films. The angle‐resolved XPS (ARXPS) spectra of these LB films with well‐defined thickness were analyzed by the Tougaard method. The inelastic mean free paths (IMFPs) in the LB film were determined to be 35.5 Å at 1382 eV and 29.1 Å at 1078 eV from analysis of ARXPS spectra taken at several emission angles (10°, 32° and 45° from the surface normal). These values are in good agreement with the reported values of bulk organic materials. Copyright © 2006 John Wiley & Sons, Ltd.
In situ electrochemical lithium intercalation into amorphous oxide thin films
Authors: Haake U. , Lützenkirchen‐Hecht D. , Frahm R. 
Published: March 2006

AbstractLithium intercalation and de‐intercalation in amorphous MoO3 electrodes were investigated using electrochemical techniques and in situ grazing incidence reflection mode X‐ray absorption spectroscopy. A new electrochemical cell suited for in situ investigations with X‐rays under grazing incidence in a protective He atmosphere was built. A Kapton sealed electrolyte compartment, the bottom of which was the amorphous MoO3 working electrode, was placed in this steel container so that a well‐defined electrochemistry analysis was possible in parallel to the X‐ray investigations. We present the results of potentiodynamic polarization experiments, as well as potentiostatic current transients, in close connection to surface‐sensitive in situ X‐ray absorption spectra. The results show that the Mo6+ ions of the amorphous oxide electrode are reduced by electrochemical lithiation, leading to a formal Mo5+ oxidation state. Angle‐dependent experiments reveal that the intercalation is not complete for the applied conditions, i.e. the Li ions are not homogeneously distributed in the entire volume of the amorphous working electrode. In addition, a certain amount of Li remains in the Mo oxide electrode after a complete intercalation/de‐intercalation cycle. The results suggest that Li ions are accumulated at the electrode/electrolyte interface during both intercalation and de‐intercalation. Copyright © 2006 John Wiley & Sons, Ltd.
Ripple structures developed on graphite layers during ion‐sputtering
Authors: Kovač J. , Zalar A. , Praček B. 
Published: March 2006

AbstractSurface roughness caused by ion bombardment can influence the sputtering yield and deteriorate the depth resolution during depth profiling. In this work, the roughening of an amorphous graphite layer 60 nm thick on a Ta layer 50 nm thick deposited on a smooth silicon substrate was studied by atomic force microscopy (AFM). The AFM measurements were carried out on the surface of the as‐deposited sample, and after ion‐sputtering with a 1 keV ion beam at ion incidence angles of 22°, 49° and 71° in the middle of the carbon layers and at the C/Ta interfaces. Ion bombardment was performed with one and two ion beams on stationary and rotating samples with an initial surface roughness amplitude Ra of 0.13 ± 0.05 nm. On stationary samples, in the graphite layer as well as at the C/Ta interface, ripple formation on the nanometre scale was found at ion incidence angles of 49° and 71°. Depending on the sputtering parameters, the wavelengths of the ripples were found to be between 18.0 ± 4.0 and 31.4 ± 4.0 nm and the amplitude between 1.0 ± 0.2 and 4.9 ± 0.2 nm, yielding a roughness parameter Ra of between 0.4 ± 0.1 and 1.6 ± 0.1 nm measured over a 1 × 1 µm area. Unexpectedly, a stronger ripple formation in the graphite layer was found at a grazing ion incidence angle of 71°. The ripple formation is suppressed by sample rotation. Copyright © 2006 John Wiley & Sons, Ltd.
Development of a ToF version of the desktop MiniSIMS: instrument design and applications
Authors: Cliff B. , Eccles A. J. , Jones C. , Long N. , Vohralik P. 
Published: March 2006

AbstractThe Millbrook MiniSIMS remains a unique concept in SIMS instrumentation, incorporating static, imaging and dynamic SIMS in a single compact desktop unit. The instrument is successfully being used in a wide range of applications, in which its low cost and high sample throughput are more important than the higher specification or flexibility in configuration of conventional instrumentation. The original MiniSIMS was designed around a quadrupole mass analyser, selected as the only type able at the time to meet the size and cost criteria appropriate to a desktop instrument. However, the sequential mass scanning needed to acquire a full spectrum is inefficient and the accepted static SIMS limit may often be exceeded during analysis of small areas. Therefore a time‐of‐flight (ToF) version has been developed in order to increase performance in areas where a low primary ion dose is critical to the analysis. Such analyses include organic species characterisation and the identification of small area surface contaminants. The instrument design is unconventional, utilising a continuous primary beam and a pulsed secondary ion beam. This allows a high duty cycle in comparison with conventional ToF‐SIMS instruments (typically > 10% compared to < 0.1%), and also depth profiling with simultaneous continuous etching and ToF mass analysis. The use of such a spectrometer is thus ideally matched to the concept of a high‐throughput instrument with static, imaging and dynamic SIMS capabilities. The instrumental design is described and data presented to compare the practical performance of the quadrupole and ToF versions of the instrument. Copyright © 2006 John Wiley & Sons, Ltd.
Measured electron IMFPs for SiC
Authors: Krawczyk M. , Zommer L. , Kosiński A. , Sobczak J. W. , Jablonski A. 
Published: March 2006

AbstractSilicon carbide (SiC) is a wideband semiconductor that is very promising for many applications in optoelectronics and microelectronics. Since information on the electron transport processes in SiC is scarce, its systematic study is highly desirable. The aim of this work is to determine experimentally by elastic peak electron spectroscopy (EPES), for the first time, the inelastic mean free paths (IMFPs) in bulk SiC with different structural properties (polycrystalline and monocrystalline materials) and surface concentrations of its constituents. The relative EPES measurements were carried out in the electron energy range 0.2–2.0 keV with two different analyzers (double‐pass cylindrical mirror analyzer (DCMA), spherical sector analyzer (SSA)) and the use of Ni standard. The measured IMFPs were uncorrected for surface excitations and compared with those calculated from the TPP‐2M and G‐1 predictive formulae using Fano plots. Good agreement was found between the measured and the calculated electron IMFPs in SiC exhibiting different structural properties. Copyright © 2006 John Wiley & Sons, Ltd.
Correlation between silicon‐nitride film stress and composition: XPS and SIMS analyses
Authors: Vanzetti L. , Barozzi M. , Giubertoni D. , Kompocholis C. , Bagolini A. , Bellutti P. 
Published: March 2006

AbstractThe characteristics of silicon‐nitride films deposited with plasma‐enhanced chemical vapour deposition (PECVD) can vary not only in composition, but also in terms of physical properties. An important parameter in the fabrication of micro‐electro‐mechanical systems (MEMS) devices is the control and tailoring of the film stress. In fact, silicon‐nitride film stress can vary from tensile (up to 800 MPa) to compressive (−500 MPa), depending on the PECVD deposition conditions (e.g. plasma pressure, plasma frequency and power).In this work, we have investigated the role of frequency mixing on the resulting film structure and stress. The layers were prepared with a commercial PECVD deposition chamber, keeping all deposition parameters constant except the ratio between low (380 kHz) and high (13.56 MHz) frequency. Film stress values were compared with compositional and chemical data from X‐ray photoemission spectroscopy (XPS) and secondary ion mass spectrometry (SIMS) measurements. These two techniques are complementary.The comparison between quantified SIMS depth profiles and the XPS HF etch‐back method shows a good agreement in nitrogen profile behaviour. In addition, XPS analyses have provided a suitable chemical characterisation of the different growth processes.We demonstrate that this analytical approach is really effective for the physico‐chemical characterisation of PECVD grown silicon nitride. Copyright © 2006 John Wiley & Sons, Ltd.
Noble gas clusters in carbon nanopores
Authors: Krainyukova Nina V. 
Published: March 2006

AbstractLow temperature high‐energy electron diffraction study of size‐dependent structures and growth mechanisms of neon and argon nanoclusters inside multiporous ‘amorphous’ carbon as well as theoretical consideration of cluster energetics with emphasis on shape optimization are presented. Multiply twinned particles (MTPs) such as icosahedra and decahedra (with fivefold symmetry) for small clusters are shown to be dominant. Applied analysis was based on the comparison of experimental and calculated intensities with the help of the R‐factor minimization procedure. The new method is applicable not only to structural studies of clusters grown in pores but also for pores characterization and can also be used in the analysis of the wide group of objects which undergo the growth typical of confined geometry. Copyright © 2006 John Wiley & Sons, Ltd.