Table of contents

SIMS depth profiles were measured using metal cluster complex ions of Ir₄(CO)₇⁺ as a primary ion beam in order to obtain high depth resolution. Depth resolution was evaluated as a function of primary ion species, energy and incident angle using a multiple boron delta-doped silicon sample. The depth resolution obtained using cluster ion bombardment was considerably better than that obtained by oxygen ion bombardment under the same bombardment condition due to reduction of atomic mixing in the depth. The best depth resolution was 0.9 nm under the bombardment condition of 5 keV, 45° with oxygen flooding, which approaches the value measured with state of the art SIMS analyses. However, depth resolution was not improved by decreasing the cluster ion energy (less than 5 keV), even though the roughness of the sputtered surface was suppressed. The limit of depth resolution improvement may be caused by a carbon cover-layer that prevents the formation of surface oxide that buffers atomic mixing. To overcome this issue, it will be necessary to eliminate carbon from the cluster ion.

Carbon fibres are continuously treated with dielectric barrier discharge plasma at atmospheric pressure in various gas conditions for adhesion improvement in mind. An x-ray photoelectron spectroscopic analysis indicated that oxygen is effectively introduced onto the carbon fibre surfaces by He, He/O₂ and Ar plasma treatments, mainly attributed to an increase in the density of the C-O single bond at the carbon fibre surfaces. The O/C ratio increased to 0.182 after 1-s He plasma treatment, and remained approximately constant after longer treatment. After exposure in an ambient air at room temperature for a month the O/C ratio at the plasma treated surfaces decreased to 0.151, which is close to that of the untreated ones. It can be attributed to the adsorption of hydrocarbon contamination at the plasma treated surfaces.

Cell differentiation properties are strongly entangled with the morphology and physical properties of the extracellular environment. A complete understanding of this interaction needs artificial scaffolds with controlled nano-/micro-topography. We induced specific topographies by nanoimprint lithography (NIL) on tissue culture polystyrene (TCPS) dishes substrates and, using light microscopy and high-magnification scanning-electron-microscopy, quantitatively compared the changes in PC12 differentiation phenotype induced by the periodicity of the nanopatterns. This analysis revealed that nanogratings reduce the number of neurites produced by PC12 cells upon treatment with NGF and that neuronal bipolarity correlated with an increased stretching of the cell body and a reduced length of the cell neuronal protrusions.

The principal materials for fabricating implants are usually metallic alloys, which have suitable mechanical and corrosion properties. Titanium and its alloys are widely used nowadays. In this work, we make a comparison of the electro-eroded surfaces of Ti, Ti6Al4V and Ti5Al2.5Fe alloys. Using the contact profilometer and confocal microscopy we obtained the roughness parameters; the differences among the samples were very small. We also studied the chemical state of the surface and the carbon-based gradient layer that was found on all the electro-eroded samples by X-ray photoelectron spectroscopy (XPS), Rutherford Backscattering Spectroscopy (RBS) and Elastic Recoil Detection Analyses (ERDA). We obtained the depth profiles of several elements in the layer, and also the hydrogen content. The layer thickness was ̃ 0.5 μm, though it was inhomogeneous. Raman spectroscopy proved the graphitic structure of the layer with various degree of crystallinity between the amorphous and crystalline state.

Catalytic activity-surface electronic structure correlation was carried out using surface XPS-UPS techniques. In situ reduction by hydrogen, were carried out at similar experimental conditions to those employed for the catalytic reactions. In the case of MoO₃ deposited on TiO₂, the reduction to MoO₂ state with the bifunctional MoO₂(H_x)_ac phase on its surface starts at 573 K and reaches a stable state at temperatures between 653–673 K. In the case of alumina support, a strong metal-support interaction takes place during the catalyst preparation, leading to Al₂(MoO₄)₃ complex formation as characterized by XRD. The reduction process(s) of this complex by hydrogen as a function of temperature is different from what is observed in the case of titania support. The changes in the chemical structure of the sample surface in both systems were tested for the catalytic reactions of 1-pentene and n-pentane

In this study, an effort has been made to prepare TiO₂ thin films by sol-gel technique with small variation of PEG to observe the gradual change of structural, optical and surface morphological properties. The X-ray diffraction study indicates that increase of PEG content enhances crystallite size but the density of crystallite is reduced. The structural, optical and surface morphological study reveals that sol gel derived TiO₂ thin film with small variation of PEG can achieve gradual change from dense random structure to early stage of porous network structure. The crystallite size, grain size, porosity and surface roughness can be efficiently modified with the small variation of PEG content.

Infrared reflection absorption spectroscopy (IRRAS) was used to investigate carbon monoxide (CO) adsorption on sub-monolayer (ML)-thick Fe deposited Pt(111). The CO exposure to a clean Pt(111) surface at room temperature yielded linear-bonded and bridge-bonded CO-Pt bands at 2090 and 1850 cm^-1. The CO-Pt band intensities decreased steeply with increasing Fe thickness. For a 1-ML-thick-Fe/Pt surface, the bridge-bonded CO-Fe band at 1950 cm^-1 dominated the spectra. Furthermore, the Fe depositions showed a new absorption band at around 2060 cm^-1. The IRRAS spectrum for CO adsorption on the 3-Å-thick-Pt-covered a 1-ML-Fe/Pt(111) surface showed a single absorption at 2070 cm^-1. Based on the IRRAS results, we discuss CO adsorption behavior on sub-ML-thick Fe/Pt(111) surfaces.

Epitaxial thin films of tungsten oxide were prepared by radio-frequency plasma oxidation of the W(110) surface followed by thermal annealing. Reflection High-Energy Electron Diffraction (RHEED) showed that the films were composed of crystal grains having a pseudo-cubic structure and (111) epitaxial plane. The re-crystallisation process led to the reduction of the tungsten oxide films. A lack of oxygen atoms was compensated by a formation of crystallographic shear planes (CSP). Deposited Pd atoms formed three-dimensional clusters with a (111) epitaxial plane reflecting the hexagonal symmetry of the tungsten oxide surface lattice. Electronic structure of the Pd/tungsten oxide/W(110) was investigated by means of X-ray Photoelectron Spectroscopy (XPS) and Synchrotron Radiation Photoelectron Spectroscopy (SRPES) methods. The epitaxial tungsten oxide thin film exhibited well-defined oxidation states indicated by narrow components in the W 4f spectrum which were not observed in amorphous phase. The deposition of Pd led to significant changes in the valence band structure but the detailed analysis of W 4f and Pd 3d lines did not show a direct interaction of Pd and W species.

The current study employs state of the art hybrid-exchange density functional theory (DFT) to investigate the Lewis acidic sites on the β-AlF₃ (100) surface. It is shown that the strong Lewis base, NH₃, binds to the surface with a binding energy of up to 1.9 eV. This demonstrates that the material is strongly Lewis acidic. We also consider the binding of the weak Lewis base CO to the surface. We calculate the shift in its stretch frequency compared to the gas phase molecule. Shifts are compared to experimental data and are shown to be typical of strong Lewis acidity.

The ultrasonic spray pyrolysis technique has been, during last three decades, one of the major techniques of synthesis a wide variety of materials. One of the most important among the ionic conductors is lithium phosphorous doped tungsten bronze.

The main goal of this investigation is producing full or hallows spheres of these bronzes of very narrow distribution. The mean size and size distribution specter of all materials were determined by the SEM analysis. The results were compared with the values obtained from the theoretical model. The assembled results indicate the possibility of a rigorous particle structure designing of all obtained powders.

We find a new relationship between the optical dielectric constant of Al dielectric films and their chemical shifts measured by X-ray photoelectron spectroscopy (XPS). We measure the difference between core-level binding energy shift for Al 1s and core-level binding energy shift for Al 2p, ΔE_1s - ΔE_2p, for AlN using high-resolution high-energy synchrotron radiation. We find that ΔE_1s - ΔE_2p correlates well with the optical dielectric constants of Al, AlN, and Al₂O₃. This is consistent with the case of our previously reported Si compounds. First-principles calculations are performed to determine the mechanism behind the observed correlation.

Carbon nanotubes have been synthesised with high density on a large area of platinum pre patterned layer of silicon nitride solid substrate by means of chemical vapour deposition of acetylene at 500 °C in ammonia ambient. The effect of the microwave induced thermal annealing, in atmospheric air, on the morphology and electrical transport properties of nanotubes films has been evaluated. At increasing annealing time the thermal treatments leads to a progressive reduction of the nanotubes' mean diameter and to a dramatic change in the electrical conductivity of the film. Such modifications have been directly attributed to a strong reduction of the amorphous carbon amount as a consequence of the thermal annealing by microwave.

The silica nano-plates formed by exfoliation of the synthetic clay Lucentite in the poly(acrylic acid) aqueous solution has been examined using near edge X-ray adsorption fine structure (NEXAFS). Mg K - edge NEXAFS analysis shows that non surface (bulk) Mg ions were not chemically involved in the poly(acrylic acid)/clay intercalation, but were substantially involved in the exfoliation resulting in the silica nano-plates. During intercalation, O K - edge NEXAFS shows structural branches on the plate surfaces were formed. During exfoliation, these increased significantly. Si L_3,2 - edge NEXAFS shows this occurred by migration of SiO₄ groups within the exfoliated silica plates.

The structure of Au-Pd nanoparticles prepared by the sonochemical method was observed by an analytical TEM. The core (Au)-shell (Pd) structure was confirmed by ADF-STEM images. The ratio of Au and Pd contents was controlled by adjusting the ratio of precursors, and the Pd-shell thickness was also controlled by the ratio of Au and Pd contents. The electron diffraction patterns showed that the lattice constant of the Pd shell is quite larger than that of bulk Pd and rather similar to that of bulk Au even in the systems with larger ratios of Pd, which supports the pseudomorphic growth of the Pd shell on the Au core.

Photoelectron emission microscopy (PEEM) excited by soft X-rays from synchrotron light source has been applied to observations on chemical-state-selective images at nanometer scale for micro-patterned silicon oxides on silicon. The micro-patterns of silicon oxides were prepared by O₂⁺ ion implantation in Si(001) using a mask of 12.5 μm periodicity. By tuning the energy of X-rays, we have observed nano-scaled images of Si-SiO_x micro-pattern depending only on the valence states of silicon. The interfaces between Si and SiO₂ became dim upon heating, but only Si (Si⁰) and SiO₂ (Si⁴⁺) were seen. It was elucidated that the annealing induces the hopping of Si valence states from Si⁰ to Si⁴⁺ without taking any intermediate valence states such as Si²⁺ and Si³⁺.

In this work secondary ion mass spectrometry (SIMS), variable angle spectroscopy ellipsometry (VASE) and atomic force microscopy (AFM) are used to investigate the structure, composition and morphology of multilayer SRON films. Three/four SRON sequential layers were deposited on silicon wafers by PECVD and silicon, nitrogen and oxygen content was varied by changing the N2O/SiH4 ratio. The total thickness of the resulting SRON stack is about 50nm. SIMS analyses of NCs+, OCs+, SiCs+, in MCs+ methodology are performed by a Cameca SC-ultra instrument. Depth profiles are obtained at 500eV of primary beam impact energy with sample rotation. An approximate method to obtain silicon concentration is used. Total layer thickness are obtained from both SIMS and VASE measurements. In addition, we compare the thickness of the single layers obtained from VASE with the SIMS depth profiles. A detailed analysis of films morphology is obtained by AFM. The SRON stack is sputtered by SIMS until a certain layer is exposed, which is then analyzed by AFM. The sputtered layers are then etched in HF solution to better resolve the exposed nano-crystals.

We report on the encapsulation of cobalt phthalocyanine (CoPc) molecules in double and multi-walled carbon nanotubes. Transmission electron microscopy imaging confirms the filling and shows pristine outer walls after cleaning. We also discuss Co 2p photoemission results, which reveal that hybridization interaction with the surrounding nanotube is likely, resulting in a peak attributed to Co(III).

Residual stress in the axial direction of the steel wires has been measured by using a method based on the combination of the focused ion beam (FIB) milling and digital image correlation software. That is, the residual stress was calculated from the measured displacement field before and after the introduction of a slot along the steel wires. The displacement was obtained by the digital correlation analysis of high-resolution scanning electron micrographs, while the slot was introduced by FIB milling with low energy beam. The fitting of the experimental results to an analytical model with the independent Young's modulus determined allows us to find the residual stress. The complete experimental procedures are described and its feasibilities are also evaluated for the thin-sized steel wires.

The drying process of linseed oil, oxidized at 80 oC, has been investigated with rheology measurements, Fourier transformation infrared spectroscopy (FTIR), and time of flight secondary ion mass spectrometry (ToF-SIMS). The drying process can be divided into three main steps: initiation, propagation and termination. ToF-SIMS spectra show that the oxidation is initiated at the linolenic (three double bonds) and linoleic fatty acids (two double bonds). ToF-SIMS spectra reveal peaks that can be assigned to ketones, alcohols and hydroperoxides. In this article it is shown that FTIR in combination with ToF-SIMS are well suited tools for investigations of various fatty acid components and reaction products of linseed oil.

We report on STM studies of a Si(111)-(7 × 7) surface with subatomic resolution. STM images with double atomic features due to the contribution of two dangling bonds of the silicon apex atom were measured at different bias voltages and tunnelling currents. The results of experiments reveal strong dependence of the subatomic features shapes on the gap resistance and the bias voltage polarity.

In this paper we report about fabrication and properties of polymethylmethacrylate doped with Er³⁺ and Yb³⁺ ions. The reported layers were fabricated by spin coating onto Si, Si/SiO₂ or onto glass substrates. For the Er and Yb doping ErCl₃ and YbCl₃ or ErF₃ and YbF₃ powder dissolved in C₅H₉NO or C₂H₆OS were used. The research was focused on investigation of the influence of the amount of the dopants on the photoluminescence spectra at 1.55 μm. It was found that the increasing Er³⁺ content increased the intensity of the luminescence and that co-doping with ytterbium ions increased the intensity of the luminescence as well.

Abstract.

The paper presents the possibility to obtain azo-polysiloxanes modified with thymine and their light induced processing with potential interest in opto-electronics or biomolecules nanomanipulation. The presence of the thymine group in the polymeric structure can confer to material biological properties, in the same time the capacity of tymine to generate H-bonds being useful to the relief geometry stabilization in time. The investigated polymers were obtained in a two step reaction, starting from a polysiloxane containing chlorobenzyl groups in the side chain. The azopolysiloxanes' photochromic behaviour was investigated in solid state, using thin films etalated on the surface of a quartz slide. The effect of surface relief structuration process under the action of UV (355 nm) laser radiation was studied. Laser induced effects on the material surface depends on the incident laser fluence and number of pulses.

Nanopolymers with different structures, shapes, and functional forms have recently been prepared using several techniques. Nanopolymers are the most promising basic building blocks for mounting complex and simple hierarchical nanosystems. The applications of nanopolymers are extremely broad and polymer-based nanotechnologies are fast emerging. We propose a nanopolymer classification scheme based on self-assembled structures, non self-assembled structures, and on the number of dimensions in the nanometer range (nD).

Two conjugated polymers comprised of fluorene and benzene and linked by vinylene bonds have been synthesized via Heck reaction. The obtained polymers were characterized by NMR, UV, fluorescent spectroscopy, GPC and thermal analysis. Both of the polymers are fluorescent and show fluorescence quenching sensitivity towards nitro-substituted compound, indicating that they have the potential to be used as sensing materials for chemical vapour.

Practical quantitative chemical state X-ray photoelectron spectroscopy (XPS) analysis of first row transition metals, oxides and hydroxides is challenging due to the complexity of their M 2p spectra. Complex multiplet splitting, shake-up and plasmon loss structure can play a role in the interpretation of the chemical states present. This paper will show practical curve fitting procedures for the quantitative measurement of different chemical states for metal oxides and hydroxides from a survey of transition metals. It will also discuss some of the limitations and pitfalls present as well as give practical examples of their successful use. These curve-fitting procedures are based on 1) standard spectra from quality reference samples, 2) a survey of appropriate literature databases and/or a compilation of literature references, 3) fitting of multiplet split spectra based on spectra of numerous reference materials and theoretical modelling, 4) spectral subtractions routines, again using reference spectra, and 5) specific literature references where fitting procedures are available.

Principal components regression (PCR) was used to calibrate time-of-flight secondary ion mass spectrometry (ToF-SIMS) positive data against X-ray photoelectron spectroscopy (XPS) data and to predict the relative atomic concentration of the (C-O) functional group on the surface of plasma treated polypropylene films. A multi-component model was constructed and was effective in predicting the relative concentration of surface functional group (C-O) with accurate prediction achieved using an external data set. ToF-SIMS with PCR modelling is demonstrated to provide an alternative method of evaluating the relative atomic concentration of surface functional groups for plasma treated polypropylene films without the need for other quantitative or semi-quantitative techniques such as XPS.

A study on nitrogen plasma functionalization of polyethyleneterephthalate (PET) is presented. The samples of PET foils were exposed to a weakly ionized, highly dissociated RF nitrogen plasma with an electron temperature of 5 eV, a density of positive ions of the order of 10¹⁵ m^-3 and a density of neutral nitrogen atoms of the order of 10²¹ m^-3. The pressure was 75 Pa and a discharge power was 200 W. The PET-samples were exposed to plasma and its afterglow from 3 s to 10 s. After the treatment the surface was analysed by XPS (X-ray photoelectron spectroscopy). XPS results showed appearance of new functional groups like amine and amide.

Ge^- ions were implanted into SiO₂ layer three times by changing the energies of 50, 20 and 10 keV to form Germanium nanoparticles at a relatively wide-depth region. Then, the samples were annealed at 600–900°C for 1 h. Although Ge-nanoparticle formation was confirmed by cross-sectional TEM observation, XPS analysis showed about 30–60 % of the Ge atoms in SiO₂ on average were oxidized. In cathode and Photo luminescence measurements, the emissions of around 400 nm in wavelength from the samples were observed. The position of cathode luminescence peak was independent of Ge fluence in the implantation, and temperature in the measurement. These results suggest that the luminescence mechanism is not due to quantum confinement effect of Ge nanoparticles, it is due to the oxygen defect center of oxidized germanium. The luminescence intensity changed dramatically with varying Ge fluence in the implantation.

Graphite surfaces were bombarded by Ar⁺ ions with and without a simultaneous Ni supply at room temperature. The sputtered surfaces without Ni supply were characterized by densely distributed conical protrusions with aligned single carbon nanofibers (CNFs) on the tops. By contrast, an excess Ni supply during Ar⁺ bombardment suppressed the CNF formation, while under the proper Ni supply conditions, single Ni-doped CNFs grew on slender needle-like structures or conical protrusions depending on the supply rate of Ni atoms. Non-doped CNFs were characterized by the amorphous-like or very fine-crystallites nature, whereas the Ni-doped CNFs were featured by polycrystalline structure. Thus, the crystalline structure was controllable by Ni doping. Because any kinds of materials can be doped into ion-induced CNFs, it is believed that the ion-irradiation method will open up a new approach to fabricate 1-dimensional composite nanomaterials at room temperature.

We will describe a technique for acquiring the current-voltage characteristics of a metal-molecule-metal probe junction in the lateral direction using a conducting probe atomic force microscopy (CP-AFM) technique. To conduct a repetitive experiment efficiently, we have utilized the current imaging mode of the CP-AFM system. We have prepared a chemically adsorbed monolayer (CAM) of 3-{6-{11-(Trichlorosilyl)undecanoyl}hexyl} thiophene (TEN) on a glass substrate. The samples with the electric path were prepared by a chemical adsorption technique with TEN on a glass substrate, followed by an electro-oxidative polymerization with pure water. The conductivity of a polythiophene derivative monolayer was investigated for its application as a wire. The corresponding I-V curves have exhibited stability and are steep in current.

In this study we experimentally observed the atomic-level morphology of Si surface in the early phase of hydrogen annealing, in order to investigate the progress of the flattening of trench sidewall surface. We performed both AFM on trench sidewall (011) surface and UHV-STM on Si (001) substrate surface. The AFM image of the trench sidewall surface within 0.5 min of H₂ annealing clearly shows the evanescence of chemical Si dioxide formed by RCA cleaning process, and in the void area without chemical oxide the appearance of atomic steps is observed. The observed Si substrate surface morphology by means of UHV-STM shows that the exposed Si surfaces reconstruct to the 2×1 dimer structure, being mono-hydrogen terminated and stabilized. From these experimental results, we can make an early phase model of hydrogen annealing, in which the evanescence of chemical Si dioxide is followed by formation and growth of voids without chemical oxide, where the exposed Si surfaces reconstruct to the 2×1 mono-hydrogen dimer structure, growing to atomic steps and terraces characteristic to the surface orientation.

Industrial applications of thermoplastic polymers are often limited by their poor adhesion properties. In this work the effect of surface oxyfluorination on the adhesion properties was investigated for polyethylene (PE), polyoxymethylene (POM), polybutylene terephthalate (PBT) and polyamide 6 (PA6). The adhesive joint strength was quantified using lap-shear tests. These results were correlated with the changes in the chemical composition of the surface, determined by X-ray photoelectron spectroscopy (XPS), in the surface free energy, measured by the contact angle method, and in the topography, using white-light confocal microscopy. The adhesive strength is strongly improved for all four polymers, but the degree of this increase depends on the polymer type. The surface free energy shows a similar trend for all four polymers. A high surface free energy exceeding 50 mN/m was observed after oxy-fluorination, whereby the polar component was strongly predominant. Surface topography measurements show no significant increase of the surface roughness. So the effect of oxyfluorination results primarily in increased wettability and polarity, due to changes of the chemical composition of the surface. XPS measurements confirm the integration of fluorine and oxygen groups in the polymer chain, which correlates with the increased polarity.

Thermoresponsive poly(N-isopropylacrylamide) layers were grafted on plasma-activated poly(ethylene oxide)-like substrate. Analysis by ToF-SIMS confirmed the presence of a pNIPAM film, which shows a phase transition temperature at 28 - 32 °C with hysteresis, as determined in-situ by quartz crystal microbalance. During the transition, the frequency of the pNIPAM coated quartz sensor exhibits a pronounced and unexpected minimum while the dissipation changes monotonously. This peculiar behaviour is explained by temporary formation of water-rich regions, which may cause delayed release and uptake of water during the collapse and re-swelling of the layer.

In this study, the optimization of gas and processing time of atmospheric pressure plasma cleaning was performed for successful ultrasonic direct bonding of electroplated Au flip chip bump. The plasma cleaning conditions strongly affected bondability of the Au flip chip bumps. The plasma cleaning with Ar gas for 1 s effectively removed contaminants from the surface without the surface oxidation, thereby improving the joint strength.

Effect of side chain length on the molecular aggregation states and surface properties of poly(fluoroalkyl acrylate)s [PFA-C_y, where y is fluoromethylene number in R_f group] thin films were systematically investigated. Spin-coated PFA-C_y thin films were characterized by static and dynamic contact angle measurements, X-ray photoelectron spectroscopy (XPS), and grazing- incidence X-ray diffraction (GIXD). The receding contact angles showed small values for PFA-C_y with short side chain (y≤6) and increased above y≥8. GIXD revealed that fluoroalkyl side chain of PFA-C_y with y≥8 was crystallized and formed ordered structures at the surface region as well as bulk one. These results suggest that water repellent mechanism of PFA-C_y can be attributed to the presence of highly ordered fluoroalkyl side chains at the outermost surfaces. The results of XPS in the dry and hydrated states and contact angle measurement in water support the mechanism of lowering contact angle for water by exposure of carbonyl group to the water interface through reorientation of short fluoroalkyl chains. The surface nanotextured PFA-C₈ through imprinting of anodic aluminum oxide mold showed extremely high hydrophobicity as well as high oleophobicity.

Compositional analysis of aluminium oxy-nitride (AlON) films deposited by reactive magnetron sputtering was performed using time-of-flight elastic recoil detection analysis (ToF-ERDA) and X-ray photoelectron spectroscopy (XPS) with sputter profiling. The composition profiles of the films depend on deposition conditions. The benefits of the different analytical methods are discussed and comparison of the profiles is performed. Conversion of the depth scale from XPS sputter time to a nm scale is implemented and the ToF-ERDA profile fitted. Densities of the deposited AlON films are calculated indicating differing film quality in agreement with the composition profile extracted.

Rare earth doped Lu₂SiO₅ thin films have been prepared by combining sol-gel process and spin coating. Annealing treatment results in the crystallization of the film and efficient incorporation of rare earth doping ions. XPS and RBS spectrocopies showed that the composition of the films is close to the nominal one. Adventitious carbon has been observed and attributed to incomplete pyrolysis of metal-organic precursors. XPS concentrations profiles show a good homogeneity for the films. RBS demonstrated some inter-diffusion between amorphous carbon substrate and silicate films resulting in a gradient of carbon at the interface between the substrate and the film itself.

Titanium oxide (TiO₂) and titanium nitride (TiN) multilayered films grown by pulsed laser deposition (PLD) technique have been tested as a heat mirror, which have a high transmittance in the visible region and a high reflectance in the infrared. Three layer TiO₂/TiN/TiO₂ heat mirrors were grown on Corning glass substrates ablating single TiN target. Switching of TiO₂-to-TiN layers composition was achieved by changing gas atmosphere (oxygen-to-nitrogen). Grown TiO₂/TiN/TiO₂ heat mirrors are highly transparent in visible (above 60% at 525nm), opaque in infrared (10% at 2600nm) and in the range from 400 nm to 2600 nm they possess almost the same properties as films prepared using two targets: TiO₂ and TiN. XPS confirms similarity of chemical composition of multilayered TiO₂/TiN films prepared by single TiN and two TiO₂ and TiN targets techniques. Furthermore, multifunctional self cleaning properties of TiO₂/TiN heat mirrors are expected through the precise control of the composition of the top TiO₂ layer operating as a photocatalyst.

TiO₂ layers for gas sensing applications were obtained by Liquid Phase Deposition (LPD). The layers were deposited on gold-coated piezoelectric quartz crystals. The surface structure, morphology and chemical properties were analysed by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and X-ray Photoelectron Spectroscopy (XPS). SEM showed that the layers were porous and composed of uniform crystalline grains. XPS indicated them to be non-stoichiometric.

We have studied thin layered Au/Pd/alumina/Cu-Al system by means of synchrotron radiation photoelectron spectroscopy (SRPES), X-ray photoelectron spectroscopy (XPS) and low energy electron diffraction (LEED). Ordered 0.8 nm thick alumina film was prepared by the controlled oxidation of the single-crystalline Cu-9at.%Al(111) support. The Pd and Au layers were prepared afterwards by a step-by-step deposition at room temperature. LEED measurement itself did not confirm epitaxial growth of the metal overlayers. They exhibited a pseudo layer-by-layer growth mode confirmed by work function measurements and the Monte Carlo simulation of the copper XPS peaks attenuation.

Low-k dielectric materials are becoming increasingly interesting as alternative to SiO₂ with device geometries shrinking beyond the 65 nm technology node. At elevated temperatures hydrogen migration becomes an important degradation mechanism for conductivity breakdown in semiconductor devices. The possibility of hydrogen release during the fabrication process is, therefore, of great interest in the understanding of device reliability. In this study, various low-k dielectric films were subjected to thermal annealing at temperatures that are generally used for device fabrication. Elastic recoil detection analysis (ERDA) was used to investigate compositional changes and hydrogen redistribution in thin films of plasma-enhanced tetraethylortho-silicate (PETEOS), phosphorus doped silicon glass (PSG), silicon nitride (SiN) and silicon oxynitride (SiON). Except for an initial hydrogen release from the surface region in films of PETEOS and PSG, the results indicate that the elemental composition of the films was stable for at least 2 hours at 450°C.

The photoemission spectroscopies play a preponderant role in the study of the electronic and compositional properties of solids. However, in standard laboratory conditions the reduced escape depth, added to low photon flux of conventional sources, make inaccessible depth profile information in a non-destructive way. In particular, the buried interfaces are not accessible for the great majority of the surface science non-destructive chemical, compositional and electronic techniques. An effective way to overcome this drawback is increasing the probing depth by analyzing electrons with a higher kinetic energy, i.e., extending the XPS to the Hard X-ray regime. Hard X-ray PhotoElectron Spectroscopy (HAXPES) is becoming an extremely powerful tool for chemical, compositional and electronic characterization of bulk and buried interfaces. A potential application of HAXPES is the determination of nondestructive compositional depth profiles in the tens nanometers scale. A methodology based on HAXPES and X-Ray Diffraction is presented through this manuscript for the determination of non-destructive compositional depth profiles.

Well-crystallized epitaxial FeTiO_3+δ films were prepared on the sapphire substrate by reactive sputtering technique. A wide range of oxygen nonstoichiometry from FeTiO₃ to FeTiO_3.5 was successfully controlled by controlling the sputtering conditions. All films had uniform structure without phase separation even for the highly oxidized FeTiO_3.5 film. Structures, magnetic and electronic properties of the FeTiO_3+δ films were seriously influenced by the oxygen nonstoichiometry. The nearly stoichiometric FeTiO₃ films had a R structure, while the nonstoichiometric FeTiO_3.5 had a R c structure. With increasing the oxygen nonstoichiometry, the valence states of Fe ions in FeTiO_3+δ were examined to be changed from Fe²⁺ to Fe³⁺ by means of both Mössbauer and XPS spectroscopy. The Ti 2p core-level XPS spectra clearly confirmed the valence states of Ti⁴⁺ ions in nonstoichiometric FeTiO_3.5. However the Ti ions in stoichiometric FeTiO₃ suggested the abundant electron density than the conventional Ti⁴⁺ ions due to the Fe²⁺ to Ti⁴⁺ intervalence charge transfer.

Non-destructive depth profile analysis with better depth resolution is required for the characterization of nano-materials and their fabrication. X-ray photoelectron spectroscopy (XPS) is the typically non-destructive analysis, however, XPS with fixed excitation energy source cannot provide depth profile without additional technique, such as ion beam sputtering. On the other hand, analyzing depth of XPS can be varied with the energy tunable excitation source, such as the synchrotron-radiation (SR), since the escape depth of the photoelectrons depends on their kinetic energy. We can obtain the XPS spectra from different analyzing depth by varying excitation energy. This technique can provide depth profile non-destructively. In the present study, Ge thin films on Si substrate has been analyzed to obtain depth profile of the thin film and buried interface of Ge/Si under the film.

In this paper we correlate the Atomic Force Microscope probe movement with surface location while scanning in the imaging and Force versus distance modes. Static and dynamic stick-slip processes are described on a scale of nanometres to microns on a range of samples.

We demonstrate the limits and range of the tip apex being fixed laterally in the force versus distance mode and static friction slope dependence on probe parameters. Micron scale static and dynamic friction can be used to purposefully manipulate soft surfaces to produce well defined frictional gradients.