bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of ZrxTi1−xO4 films produced by PLD and MOCVD techniques
Authors: Kaciulis S. , Cusmà A. , Padeletti G. , Pandolfi L. , Viticoli M. , Zaldo C. 
Published: August 2004

AbstractZrxTi1−xO4 (ZT) thin films have been deposited by pulsed laser deposition (PLD) and metallo‐organic chemical vapour deposition (MOCVD) on Pt‐covered and naked Si(100) substrates. Both techniques provide single‐phased films with a columnar structure when the substrate is heated to the 500–600 °C range. Out of this temperature range the co‐existence of other titanium oxides has been shown by XRD and XPS studies. XPS results show that the composition of optimized films is constant along the film thickness and that PLD films have higher Zr concentration than MOCVD ones. Pt induces the orientation (111) of ZT films, while the higher temperature promotes either (020) ZT orientation in PLD films or (031) ZT texture in MOCVD ones. Copyright © 2004 John Wiley & Sons, Ltd.
Plasma surface modification of Ti and TiAlV alloy
Authors: Mohai M. , Tóth A. , Sajó I. , Ujvári T. , Bertóti I. 
Published: August 2004

AbstractSurface modification of commercially pure Ti and of Ti6Al4V alloy samples was performed by plasma immersion ion implantation with 25 kV energy. Plasma was generated by RF discharge in air, in nitrogen, or in a mixture of nitrogen and methane. Treatment in air plasma produced an oxide layer on the surface without appreciable incorporation of nitrogen, as detected by XPS. Significant surface enrichment of aluminium was measured after air plasma treatment of Ti6Al4V, but no such segregation was observed after nitrogen plasma treatment. These effects are interpreted by involvement of thermodynamic driving forces. Development of rutile and a sub‐stoichiometric oxide were identified on Ti while no crystalline phases could be evaluated on the Ti6Al4V upon oxidation. The cubic TiN phase was found after nitrogen PIII treatment on both Ti and Ti6Al4V. Nanomechanical tests showed a significant increase in the hardness for Ti6Al4V after oxidizing PIII treatment in air. Considerable change in hardness could not be measured, however, after nitriding PIII treatments. Copyright © 2004 John Wiley & Sons, Ltd.
Deposition and characterization of ZrTiO4 thin films
Authors: Pandolfi L. , Kaciulis S. , Padeletti G. , Cusmà A. , Viticoli M. 
Published: August 2004

AbstractThin films of zirconium titanate ZrTiO4 (ZT) were prepared by the MOCVD technique. ZT layers were deposited in air on silicon substrates by using a non‐conventional MOCVD system. The chemical composition of these films was investigated by XPS. More information on the thin film structure was obtained from the study of the Zr 3d XPS signal. The temperature of the substrate was found to be a fundamental parameter determining the stoichiometry of the films. It influences also the ordered or disordered structure of the films produced. In addition, the surface roughness of the samples before and after Ar+ ion sputtering was investigated. Copyright © 2004 John Wiley & Sons, Ltd.
Influence of magnetron deposition parameters on the stoichiometry of sputtered V2O5 films
Authors: Silversmit G. , Poelman H. , De Gryse R. 
Published: August 2004

AbstractVanadium oxide films were deposited on Si(100) substrates by reactive DC magnetron sputtering in an O2 atmosphere. The substrate temperature, oxygen pressure and sputter time were varied and their influence on the stoichiometry was examined. V 2p XPS measurements were used to determine the degree of oxidation of the sputtered vanadium oxide films. Nearly fully oxidized (V5 +) vanadium oxide films were deposited over the whole temperature and pressure range. However, at higher sputter pressures, oxidation of the Si substrates occurred, accompanied by reduction of the vanadium oxide stoichiometry. A short Ar+ bombardment for removal of surface contamination induced a strong decrease of the V5 + concentration in the vanadium oxide films. Copyright © 2004 John Wiley & Sons, Ltd.
Effect of the oxygen deficiency of ceramic TiO2−x targets on the deposition of TiO2 thin films by DC magnetron sputtering
Authors: Poelman H. , Tomaszewski H. , Poelman D. , Depla D. , De Gryse R. 
Published: August 2004

AbstractThe sputter deposition of stoichiometric TiO2 thin films has been investigated, in view of photocatalytic application. DC magnetron sputtering from ceramic targets in an argon/oxygen atmosphere was chosen as the deposition technique. Composite TiO2Ti targets with metallic Ti fraction from 0 to 70 wt% were prepared from TiO2 and Ti powders following a standard ceramic procedure.The influence of target composition and sputter parameters on the film composition was examined by means of optical transmission measurements, XRD and XPS. From the former, optical absorption coefficients are calculated, which are used as a measure for the films' stoichiometry. Curve fitting of the Ti 2p3/2 photoemission line yields the composition in terms of the presence of reduced species.Upon sputtering in argon, translucent layers are obtained for targets with up to 35 wt% Ti. For higher amounts, the optical absorption coefficient α at 550 nm increases and the layers become dark. With increasing metal Ti contribution and argon flow, more reduced Ti species contribute to the Ti 2p photoemission line.In reactive sputter mode, near‐stoichiometric TiO2−x films are obtained for low oxygen mole fractions. For higher oxygen contributions, reduced Ti species are increasingly present for all targets. This reduction is ascribed to active re‐sputtering of the deposited layer by O− ions and the sputter yield difference between oxygen and titanium. Copyright © 2004 John Wiley & Sons, Ltd.
RBS and XPS study of TiOx layers prepared by the PVD technique
Authors: Macková A. , Peřina V. , Krumeich J. , Zemek J. , Kolouch A. 
Published: August 2004

AbstractThe PVD coatings were prepared using Sulzer Innotec's closed magnetic field unbalanced magnetron sputtering facility. The deposition parameters of bias and oxygen flow rate were varied. The prepared samples were analysed by RBS (Rutherford backscattering spectrometry) to determine the Ti/O ratios and the thicknesses of the coatings, and by ERDA (elastic recoil detection analysis) to investigate the hydrogen content in the surface layer. XPS was used to characterize the near‐surface composition and chemical bonding. Measurements of mechanical properties (hardness and thickness) were performed. We concluded from RBS analysis that Ti content is enhanced according to the increased bias and the decreased oxygen flow rate. We observed the increasing hardness in the case of the higher Ti content layers prepared. We found that a contaminated surface layer exists in which hydrogen, oxygen and carbon are incorporated. Copyright © 2004 John Wiley & Sons, Ltd.
Experimental verification of PTC diagrams for TiC and ZrC PVD coatings and determination of free carbon state by AES, XPS and HREELS methods
Authors: Kovalev A. I. , Wainstein D. L. , Karpman M. G. , Sidakhmedov R. Kh. 
Published: August 2004

AbstractSeveral PVD coatings based on Ti and Zr carbides and on HSS steel were investigated. The partial pressure of the active gas (N2, C2H2) and substrate temperature were varied over a wide range. The PTC diagrams for prediction of coating compositions, dependent on substrate temperature and gas pressure, were calculated using the thermodynamic technique for phase equilibria based on the principle of maximum entropy in an isolated thermodynamic system. The chemical composition, and electronic and atomic structure of coatings were investigated using the AES, XPS and HREELS methods. Comparison of the calculated chemical composition of coatings with one measured by AES shows good agreement. XPS analysis of the C 1s line in carbides of Ti and Zr shows the presence of carbon in non‐stoichiometric carbides and in the free state. The fraction of bound and free carbon was measured by relation of the shifted and normal C 1s peaks. HREELS spectra near the line of elastically scattered electrons show a peak at 165 meV (1332 cm−1 in Raman spectroscopy) corresponding to sp3 hybridization of carbon. Copyright © 2004 John Wiley & Sons, Ltd.
The cathodoluminescence generated in ZnS phosphor powder with non‐luminescent ZnS coatings: a comparison of experimental data with Monte Carlo calculations
Authors: Swart H. C. , Greeff A. P. 
Published: August 2004

AbstractField emission displays (FEDs) are a possible alternative to other display technologies. They work similarly to CRTs, but instead of an electron gun they have an array of tiny metallic tips acting as electron emitters. This array is situated in close proximity to the phosphor screen and produces light by a process of cathodoluminescence (CL). During prolonged electron beam irradiation a non‐luminescent ZnO layer forms on the irradiated surface of the ZnS phosphor powder according to the electron‐stimulated surface chemical reactions (ESSCR) mechanism. The low‐energy electrons used in FEDs have a shallow penetration depth and since the CL is dependent upon the energy loss in the ZnS bulk itself, growth of the ZnO layer significantly degrades the CL intensity. Monte Carlo techniques may be used to simulate the electron trajectories and energy loss in many different types of materials. Energy loss profiles in the ZnS for different non‐luminescent ZnS coatings of known thickness were determined using the Monte Carlo electron trajectory simulations. Since only energy loss in the ZnS powder results in CL an increase in the thickness of the ZnS coating decreases the CL intensity accordingly. Simulations were performed for electron energies varying from 2 to 10 keV and at incident angles accommodating for the morphology of the phosphor powder. These results compared very well with the experimental results measured by other authors. Copyright © 2004 John Wiley & Sons, Ltd.
Annealing of CVD un‐doped diamond: a photoemission investigation
Authors: Filippi M. , Calliari L. , Pucella G. , Verona‐Rinati G. 
Published: August 2004

AbstractThe temperature evolution of the surface region of an undoped chemical vapour deposited (CVD) diamond film is characterized via UV and x‐ray induced photoemission. Methods are proposed to diagnose and to overcome possible electrostatic charging problems connected with the poor conductivity of the film. The position of the relevant energy levels is measured and the transition from a negative to a positive electron affinity surface is observed. For the bare diamond surface, an electron affinity χ = 0.4 eV is derived while the film conductivity is shown to decrease on going from the surface towards the bulk. Copyright © 2004 John Wiley & Sons, Ltd.
Characterization of the interface of PZT sol–gel layers on metallic substrates
Authors: Dutschke Anke , Meinhardt Jürgen 
Published: August 2004

AbstractFerroelectric lead zirconate titanate layers can be used for several industrial applications. Usually they are prepared as thin films on silicon substrates with different ground electrodes to be integrated into microelectronic devices. Thin steel substrates are of special interest because of their flexibility which enables several new applications in sensors and actuators. These applications require a film thickness of several micrometres, which can be achieved by several coating and annealing steps.We have studied the interfaces of sol–gel derived PZT (53/47) layers on a commercially available CrNi alloy in view of formation of secondary phases and diffusion processes, using transmission electron microscopy (TEM) combined with energy dispersive x‐ray spectroscopy (EDX) and XPS. The effect of different thermal annealing treatments on the thickness of a non‐ferroelectric interface containing NiO and NiCr2O4 between the steel substrate and PZT film was studied. The diffusion of Cr from the metallic substrate into the PZT layer during the annealing process leads to formation of Pb2(CrO4)O at the interface. The results are related to the electrical properties of the films. Copyright © 2004 John Wiley & Sons, Ltd.
Investigation of the nickel/emissive oxide interface in thermionic emitters
Authors: Barber D. K. , Jenkins S. N. , Whiting M. J. , Baker M. A. 
Published: August 2004

AbstractOxide cathodes act as electron sources in cathode‐ray tubes (CRTs). In an attempt to understand the processes leading to degradation in their performance over their lifetimes, SEM, EDX and AES have been used to examine the Ni base/emissive oxide interface. Oxide cathodes from dummy electron gun tubes were investigated after 0 h and 1000 h lifetime testing. The interface was studied (a) from above, by stripping away the emissive oxide using adhesive tape, and (b) in cross‐section. After fabrication and processing (0 h exposure), cracks exist at grain boundaries on the surface of the Ni base, probably due to thermal grooving. The activator elements, Al and Mg, are enriched on the metal surface: Al on the Ni surface and Mg at the crack mouths. After 1000 h of lifetime testing the cracks had widened and deepened, and the activator concentrations in the interface region had increased. Cross‐sections reveal that chemical processes involving Mg occur primarily within the cracks, whilst those involving Al predominate at the Ni/oxide interface and on the oxide layer itself. An interfacial layer develops during cathode operation containing the elements Al, Mg, Ba and Sr. Further work is required to fully understand the degradation and activator reaction processes and to clarify the principal mechanism leading to reduced cathode performance as a function of lifetime. Copyright © 2004 John Wiley & Sons, Ltd.
A study of the formation of yttrium silicides epitaxially grown on Si(111)
Authors: Rogero C. , Polop C. , Sacedón J. L. , Martín Gago J. A. 
Published: August 2004

AbstractWe present an investigation of the growth of ultrathin yttrium silicide films (YSi2) epitaxially grown on n‐type Si(111) as a function of the thermal treatment. Combining STM images with a quantitative spot profile LEED analysis we have studied the crystalline quality of the YSi2−x (0 ≤ x ≤ 0.3) and we have related it to the silicide formation temperature. We have distinguished a short temperature range for the formation of the two‐dimensional p(1 × 1) YSi2, and three growth regimes for the three‐dimensional (√3 × √3)R30° YSi1.7. For annealing temperatures lower than 375°C the silicide is not completely formed; at around 420°C the surface exhibits long atomically flat terraces, and for temperatures higher than 525°C a significant increase in the number of defects takes place. Copyright © 2004 John Wiley & Sons, Ltd.
XPS study of Cu/substrate systems obtained by pulsed laser deposition
Authors: Lai X. Ch. , Pushkin M. A. , Troyan V. I. 
Published: August 2004

AbstractIn this paper XPS was used to study the evolution of Cu 2p3/2 peaks with the increase of the metal coverage on different types of substrate: Ni, HOPG (highly orientated pyrolytic graphite) and KBr. The results showed that: (i) the binding energy of the Cu 2p3/2 peak in the system Cu/HOPG decreases with surface coverage, while in the system Cu/Ni it increases; (ii) with the increase of the Cu coverage in all the systems studied a general trend of the Cu 2p3/2 peak is the reduction of FWHM (full width at half maximum), but the degree of the FWHM change depends greatly on the type of the substrate. The results obtained for binding energy change are discussed in relation to the initial and final state contributions. The results indicate that the final state contributes more to the change of the binding energy in the more 3‐dimensional structure Cu/HOPG system, while in the more 2‐dimensional Cu/Ni system the initial state contribution dominates. The FWHM change is analysed in terms of the size distribution of clusters and change of the lifetime of the holes left by the photoelectrons, which is affected by the size of the clusters and the degree of the hybridization between the s and d electrons. Copyright © 2004 John Wiley & Sons, Ltd.
Characterization of thin oxide films on GaAs substrates by optical methods and atomic force microscopy
Authors: Franta D. , Ohlídal I. , Klapetek P. , Ohlídal M. 
Published: August 2004

AbstractIn this paper the results of optical and atomic force microscopy characterization of oxide thin films prepared by thermal oxidation of GaAs single crystal wafers at a temperature of 500°C in air are presented. The optical characterization is performed using multi‐sample modification of the method based on combining variable angle spectroscopic ellipsometry and near‐normal spectroscopic reflectometry. It is shown that the films exhibit the rough lower boundaries and refractive index profile inhomogeneities. The spectral dependences of the refractive index and extinction coefficient of these films are presented within the wide spectral region, i.e., 210–900 nm. The values of the thicknesses and roughness parameters characterizing the oxide films are introduced as well. Copyright © 2004 John Wiley & Sons, Ltd.
Characterization of sol–gel derived glass composite thin films
Authors: Shimamura A. , Hübert Th. , Thust H. 
Published: August 2004

AbstractA comprehensive analysis of composition and structure is essential for the development of new materials with tailored properties. We will demonstrate the application of SEM, XPS and XRD for the development of thin films containing nano‐scaled electrical conductive particles for application in hybrid resistors.The films were prepared using the sol–gel process and precursor solutions were synthesized from an acid hydrolysis of a mixture of TEOS, water and ethanol. Alcoholic solutions of ruthenium chloride were then allocated to obtain up to 30 vol% filler in the films. The films were precipitated by dip‐coating on silicon, silica or glass sheets and heat treated at up to 600°C in air or nitrogen atmospheres.A nano‐structured morphology could be identified consisting of homogeneously dispersed crystalline RuO2 particles of 10 to 180 nm in size, in an amorphous SiO2 matrix. Film morphology can be varied using the synthesis process. The resistivity of the films was measured by an I–V measurement system. It changes drastically from 109Ω·cm to 10−2Ω·cm according to the amount of dispersed conductive particles.The results show that composition–structure–property relations can be described by use of sophisticated analytical methods. Copyright © 2004 John Wiley & Sons, Ltd.
Surface investigations of bonded perfluoro polyether monolayers on gold surfaces
Authors: Alamarguy D. , Noël S. , Schneegans O. , Meyer R. , Tristani L. , Di Meo A. 
Published: August 2004

AbstractThin films of functionalized perfluorinated polyether have been deposited on gold surfaces. XPS of freshly deposited layers rinsed in the proper solvent has shown that a thiolate bond is formed. Spectra performed on layers aged 15 days before the rinsing process display drastically different features. Fewer molecules are rinsed off and the main component of the sulfur peak corresponds to free sulfur. Conducting‐probe AFM is then used to characterize the mechanical and electrical properties of these layers. Confirmation of the higher thickness of the aged rinsed films is obtained from the delay between the mechanical and the electrical contacts. Copyright © 2004 John Wiley & Sons, Ltd.
XPS analysis of electronic density of iron tetraazamacrocycle through Fe 2p binding energies on the 3‐imidazolilpropyl‐modified surface of oxidized n‐Si(100)
Authors: Andresa Juliana Salvador , Moreira Leonardo Marmo , Magalhães Janildo Lopes , Gonzalez Eduardo Perez , Landers Richard , Rodrigues‐Filho Ubirajara Pereira 
Published: August 2004

AbstractThis paper describes the preparation of metallo‐organic thin films of [FeTIM(CH3CN)2]2 + complex, where TIM stands for 2,3,9,10‐tetramethyl‐1,4,8,11‐tetraazacyclotetradeca‐1,3,8,10‐tetraene on oxidized silicon wafer, SiO2/Si, previously treated with 3‐imidazolilpropyltrimethoxysilane, 3‐IPTS. X‐ray photoemission lines of Fe 2p were used to probe the iron chemical environment in the physically and chemically adsorbed macrocycle complexes. As FeTIM can bind CO, NO or N‐heterocycle, a built‐on Si wafer sensor device could be envisaged for these molecules. Copyright © 2004 John Wiley & Sons, Ltd.
In situ analysis of PMPSi by spectroscopic ellipsometry and XPS
Authors: Čechal J. , Tichopádek P. , Nebojsa A. , Bonaventurová Zrzavecká O. , Urbánek M. , Spousta J. , Navrátil K. , Šikola T. 
Published: August 2004

AbstractIn the paper in situ monitoring of the UV‐light‐ and thermal‐treatment of PMPSi thin films by real‐time spectroscopic ellipsometry and XPS is reported. The films were treated both under ultrahigh vacuum and oxygen atmosphere. The results of this study indicate that the SiSi bonds in the polymer main chain (Si‐backbone) were primarily broken at the UV‐light treatment. However, the Si radicals recombined into the polymer‐like chains causing no remarkable chemical shifts. The UV‐light treatment under enhanced sample temperature (≈80 °C) in oxygen atmosphere resulted in the more intense degradation of the PMPSi film. This can be related to cutting off the volatile methyl groups from the polymer main chains. Copyright © 2004 John Wiley & Sons, Ltd.
ToF‐SIMS investigations of the degeneration processes of self‐assembled monolayers of alkanethiols on gold
Authors: Sohn S. , Schröder M. , Lipinsky D. , Arlinghaus H. F. 
Published: August 2004

AbstractTime‐of‐flight secondary ion mass spectrometry (ToF‐SIMS) has been used to study the degeneration process of self‐assembled monolayers (SAMs) of alkanethiols on gold upon ambient air exposure. Alkanethiol SAMs with varying alkyl chain length n ranging from n = 1 to n = 17 were prepared simultaneously and analysed after being stored at ambient air for specific time periods. Static SIMS spectra show a range of mass signals characteristic for non‐degenerated SAMs, like gold‐alkanethiolate clusters, on the one hand, and for degenerated SAMs, like alkanesulfonates, on the other. These characteristic mass signals enable the observation of degeneration processes. We found that the rate of degeneration increases rapidly with decreasing alkyl chain length. Furthermore, for short‐chain alkanethiol SAMs with n ≤ 3, a randomly initialized degeneration plays a major role, whereas for long‐chain alkanethiol SAMs, the degeneration starts at domain boundaries and defects, propagating into intact domains. Copyright © 2004 John Wiley & Sons, Ltd.
Difference in the annealing behaviour of thin films of PS/PMMA blends and copolymers as revealed by ToF‐SIMS and AFM
Authors: Kailas L. , Nysten B. , Bertrand P. 
Published: August 2004

AbstractSurface characterization of thin films of polystyrene (PS)/poly(methyl methacrylate) (PMMA) blends and diblock copolymers was done using time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS) and atomic force microscopy (AFM) in order to compare their annealing behaviour. The spin‐cast films, of 12 nm thickness, were annealed at 160°C for different time periods ranging from 2 hours to 1 week. ToF‐SIMS spectra of annealed blends showed a decrease in the concentration of PS and an increase in the concentration of PMMA on the surface as compared to the as‐cast sample. The spectra of copolymers showed an increase in concentration of PS on the surface on annealing, with PMMA concentration decreasing. AFM images with the help of SIMS information allowed us to conclude that in the case of blends, PS formed droplet‐like domains on a PMMA matrix and, in copolymers, PS with its lower surface free energy segregated to the surface without complete phase separation, which is not possible for copolymers. Copyright © 2004 John Wiley & Sons, Ltd.