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A thin passive titanium dioxide, in its stoichiometric form, has a very high corrosion resistance, but the same conclusion can not be made on corrosion resistance of a surface which is not stoichiometrically titanium dioxide, or even a surface which is a composition of various elements and oxides. In practice, the implants available on the market have an oxide surface contaminated with other elements. The aim of this paper is to correlate clinical observations that show the deterioration of Ti made implants after certain period of insertion in the patients, and in vitro corrosion resistance of Ti implants with surface passive oxide layer. For this purpose, surface analysis of the retrieved failed implants were performed and in vivo animal experiments with relation to ion release from implants were done. Finally, on the basis of the clinical observation, in vivo animal test, and in vitro electrochemical corrosion test, a model is proposed to explain the corrosion and ion release from the Ti implant.

Diamond-like carbon (DLC) films were deposited with a RF magnetron sputtering device. The target used was high purity graphite (99.999%) and n-type Si was used as the substrate. In order to get good anti-reflective films nitrogen gas was used to a small extent in addition to hydrogen gas thus resulting in a-C:H:N thin films. From the Ellipsometry studies it was found that the deposited films were good for optical coating. XPS studies indicate that film contains carbon in graphitic form, DLC form and CN bonding in sp² trigonal and sp³ tetrahedral structure. FT-IR spectra analysis agrees with the results of XPS data. AFM studies show that the surface roughness of the films depend on the film composition.

Atomic environment of xFe₂O₃·(80-x)Bi₂O₃·20Ga₂O₃ heavy glasses (0≤x≤20 mol%) was investigated with respect to electronic structure of the samples. Data obtained from Bi 4f, Ga 2p, Fe 2p, and O 1s core-level photoelectron spectra indicate changes in the local order on the account of partial substitution of bismuth by iron. The bismuth cations behave essentially as network formers while the iron and gallium ones acts as network modifiers. The number of nonbridging oxygens depends on Fe₂O₃ content.

Amorphous carbon nitride films (a-CN_x) were deposited by pulsed laser deposition of camphoric carbon target at different substrate temperatures (ST). The influence of ST on the bonding properties of a-CN_x films was investigated. The nitrogen to carbon (N/C) atomic ratio and oxygen to carbon (O/C) atomic ratio, bonding state and microstructure of the deposited a-CN_x films were characterized by X-ray photoelectron spectroscopy and confirmed by other standard measurement techniques. The bonding states between the C and N, and C and O in the deposited films are found significantly influenced by the ST during deposition process. The N/C and O/C atomic ratio of the a-CN_x films reached the maximum value at 400°C. The ST of 400°C was proposed to promote the desired sp³-hybridized C and the C₃N₄ phase. The C–N bonding of C–N, C=N and C–N were observed in the deposited a-CN_x films.

The present work is devoted to the study of some properties (size, electronic state, redox properties, interaction with matrix) of gold clusters and nanosized particles in Na-Y zeolite modified by iron. Two methods of iron introduction were applied: wet-impregnation and ion-exchange, which result in different structure and reducibility of iron species. Aggregation of iron species and their probable dissolution during gold deposition in samples prepared by wet-impregnation permits to form new Au, Fe and Au-Fe species in contrast to samples prepared by ion-exchange. The strong interaction of Au with Fe species in Au/Fe-imp/NaY changes noticeably a behavior of gold nanoparticles under heating.

In this study, we have investigated the structural, interfacial and ferroelectric properties of Sr_1-xCa_xBi₂Ta₂O₉ thin films grown on Pt/TiO₂/SiO₂/Si substrates using pulsed-laser-deposition technique. The decrease in lattice parameters with increasing Ca content was attributed to the smaller ionic radius of Ca. Atomic force microscopy shows that the average grain size and surface roughness of the films increases with the incorporation of Ca. Films with x=0.2 exhibited a maximum remanent polarization of ~23.8 μC/cm² with a coercive field of 175 kV/cm. The higher remanent polarization was attributed to the increased grain size and to the increase in the lattice mismatch between TaO₂ and SrO planes. The presence of metallic bismuth at the interface of the film and the substrates was confirmed using XPS depth profile analysis. The current transport property of the thin film capacitors suggests a bulk-limited dc-current conduction mechanism.

P-type (Al, N) co-doped ZnO films have been prepared by thermal oxidation of sputtered Zn₃N₂:Al precursor films. The Zn₃N₂:Al precursors are deposited by RF magnetron sputter and then annealed in oxygen atmosphere at different temperatures. The doped ZnO films are characterized by XRD, XPS and Hall effect measurement. The results indicate that the ZnO films only show p-type conductivity with an annealing in a temperature window: ZnO films show the best p-type characteristics with a hole concentration of 4.2 × 10¹⁷cm^-3, mobility of 0.52 cm/V.s and resistivity of 28Ωcm after an annealing at 550°C. Using these p-type ZnO films, ZnOp-n junctions are prepared which show good diode characteristics. The chemical states of N and Al dopants in the ZnO host material are investigated by XPS method after annealing at different temperatures; and the doping mechanisms are discussed based on the XPS results.

We have thoroughly investigated the oxygen loss in PrMnO₃ and BaMnO₃, the end members of the AMnO₃ system, on in situ heating in a reducing atmosphere. This was done to drive some oxygen out from them and thus possibly alter the valence of the Mn cation. Sample characterization was done through X-ray diffraction and SEM measurements. The core-level photoemission point to oxygen loss from only BaMnO₃ changing some of Mn⁴⁺ to Mn³⁺ in it, transfer of some spectral weight to the highly localized Fehrenbacher–Rice states and an increased Mn 3d–O 2p hybridization. Magnetization measurements show that at low temperatures, the samples depict a canted antiferromagnetic ordering.

The preparation of Co₃O₄ films containing 1-D interlinked nanowires by electrochemical deposition technique using CH₃COO)₂Co.4H₂O solutions in distilled water and study of their optical properties are reported in this paper. The films are characterized by using XRD, UV-visible & FTIR spectroscopies, XPS and SEM. The characterization studies showed that the resultant films are impurity free, phase pure Co₃O₄ with cubic spinel symmetry and contain 1-D interlinked nanowires having diameter & length between 250-350 nm & 2-10 μm respectively. The resultant films showed the better values of absorptance (α) = 0.94, emittance (ε) = 0.17 and selectivity = 5.529 as compared to reported data. These films are found to have good prospects for selective solar absorption coatings because their optical properties indicate the red shift of absorption peaks, exhibiting thereby quantum-confined effect and behavior of semiconductor.

In order to investigate the effects of Ba doping BiFeO₃ on multiferroic properties, Bi_1-xBa_xFeO₃(0≤x≤1)(Ba_xBFO) ceramics were fabricated via rapid solid phase sintering method, and material's structures and electrical properties were investigated. The phase transitions from rhombohedral to pseudo-cubic (x = 10%) and then to tetragonal (x = 40%) were confirmed by X-ray diffraction investigation. Although the electrical conductivity of Ba_xBFO (x = 10%, 20% and 30%) ceramics was low, which is a similar trend to previous reports, an abnormal enhancement of electrical conductance was observed in Ba_xBFO (x = 1%, 3% and 5%) ceramics. Such as, the electrical conductivity of Ba_0.03BFO is calculated to be ~10⁶ Ω⋅cm that is five orders of magnitude higher than that of the BiFeO₃. This has been discussed and ascribed to more percent of oxygen vacancies and Fe²⁺ ions in Ba_xBFO ceramics, as confirmed by X-ray photoelectron spectroscopy investigation.

The local atomic and electronic structure of La_0.5Sr_0.5MnO₃ was investigated at different annealing temperatures (T_A) by X-ray absorption spectroscopy (XAS) and photoemission spectroscopy (XPS). The extended X-ray absorption fine structure indicates that the MnO₆ octahedral distortion is reduced by increasing T_A. The chemical shift for the sample with T_A = 1350°C measured by XPS of Mn 2p core level demonstrates the increasing of Mn³⁺ ions content. From the deconvolution of valence band photoemission spectra, the number of e_g electron is also proved to increase with increasing T_A. It is also demonstrated that there is a strongest hybridization between O 2p and surrounding atomic orbital states in sample with T_A = 1350°C, which is consistent with valence band photoemission.

The spectroscopic study of La₂O₃ thin films deposited over Si and SiC at low RF power of 25 W by using indigenously developed plasma-enhanced atomic layer deposition (IDPEALD) system has been investigated. The tris (cyclopentadienyl) lanthanum (III) and O₂ plasma were used as a source precursor of lanthanum and oxygen, respectively. The $\sim$1.2 nm thick La₂O₃ over SiC and Si has been formed based on our recipe confirmed by means of cross-sectional transmission electron microscopy. The structural characterization of deposited films was performed by means of X-ray photoelectron Spectroscopy (XPS) and X-ray Diffraction (XRD). The XPS result confirms the formation of 3${}^{+}$ oxidation state of the lanthania. The XRD results reveals that, deposited La₂O₃ films deposited on SiC are amorphous in nature compare to that of films on Si. The AFM micrograph shows the lowest roughness of 0.26 nm for 30 cycles of La₂O₃ thin films.

The structure and thermal properties of Ba${}_{0.5}$La${}_{0.5}$MnO₃ polycrystalline powder have been investigated using X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) techniques. The structural studies have shown that Ba${}_{0.5}$La${}_{0.5}$MnO₃ compound crystallizes in perovskite structure with Pm-3m cubic symmetry group. The lattice parameters were obtained to be a = b = c = 3.9073 Å. Mass changes have been observed from thermogravimetric (TG) and differential thermogravimetric (DTG) curves obtained in a wide temperature interval of 30–950${}^{\circ }$C. Free energy and enthalpy changes for all observed transformations were determined. Observed endo and exo effects.

The atomic environment of 20MnO · 80(xBi₂O_{3 · y}PbO) glass samples having the ratio of bismuth to lead atoms of 8:1 and 3:1 was investigated with respect to the thermal induced structural changes, cationic field strength and electronic structure of the compound. The position and full width at half maximum of X-ray photoelectron peaks were estimated using spectra simulation based on the summation of Lorentzian and Gaussian functions. Data obtained from XPS core-level spectra Bi 4f, Pb 4f, Mn 2p, and O 1s indicate a reduction of glass disorder both by heat treatment and by increasing the PbO content in the samples. The cations behave essentially as network formers that could be correlated with an intermediate range structure.

Experimental formation of LPO (liquid phase oxidation)-grown InGaP native oxide near room temperature (~60°C) is demonstrated. A high oxidation rate is obtained and checked by SEM and AES. The native oxide is determined to be composed of InPO₄ and Ga₂O₃, analyzed by the results of XPS measurement. Due to the presence of the excellent quality of InGaP native oxide, high hydrogen (H₂) sensitivity in output current of a Pd/oxide/InGaP MOS Schottky diode is observed. Under the applied voltage of -1 V and 50 ppm H₂/air, a high sensitivity of 1090 is obtained. An obvious variation of output current and a short response time due to the exposure to different H₂ concentration are also achieved. For example, the adsorption (τ_a) and desorption (τ_b) time constants under 50 ppm H₂/air are 2.3 s and 2.7 s, respectively.

In this paper, Nitinol, an equiatomic binary alloy of nickel and titanium, was surface modified for its potential biomedical applications by chemical and electrochemical etching. The main objective of the surface modification is to reduce the nickel content on the surface of Nitinol and simultaneously to a rough surface microstructure. As a result, better biocompatibility and better cell attachment would be achieved. The effect of the etching parameters was investigated, using scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectrometry (EDX) and X-ray photoelectron spectrometry (XPS). The corrosion property of modified Nitinol surfaces was investigated by electrochemical work station. After etching, the Ni content in the surface layer has been reduced and the oxidation of Ti has been enhanced.

In this paper, we report the effect of etching time on the morphological, structural and electrical properties of porous silicon (PSi) synthesized by electrochemical anodization of low resistivity p-type crystalline silicon at current density of 15 mA/cm². Atomic force microscopy (AFM) measurements showed that the square root of roughness is increased with etching time. Scanning electron microscopy (SEM) investigations revealed that the microstructure of porous silicon is varying with etching time and pores from nano-size to micro-size were formed. Energy dispersive X-ray (EDX) analysis confirmed that the amount of oxygen increases with etching time. Porosity and thickness estimated gravimetrically showed a dependence on the anodization time. The room temperature dark electrical resistivity of porous silicon has observed to be increased with etching time. X-ray photoelectron spectroscopy (XPS) analysis of synthesized porous silicon has shown peaks of C 1s, Si 2p, O 1s, F 1s and N 1s. Current–voltage (I–V) characteristics of synthesized Al/PSi/c-Si junctions prepared at different etching times are investigated and analyzed. The ideality factor, barrier height and built-in potential of porous silicon junctions were strongly found to be dependent on the etching time.

Ball milling technique has been extensively used to prepare different metastable states with nanocrystalline microstructures from intermetallic compounds. The present study was made on the identification of the changes in magnetic and electronic properties as a result of high-energy ball milling of Fe-50 at.%Al alloy samples. The phase formation and physical properties of the alloys were determined as a function of milling time by means of Mössbauer and X-ray photoelectron spectroscopy (XPS). The Mössbauer results show the formation of nanostructured body-centered cubic (BCC) FeAl alloy only after 5 h of mechanical milling and the same is also confirmed by Scanning electron microscope (SEM) and Transmission electron microscopy (TEM) studies. Mössbauer studies further confirm that there is magnetic behavior retention in the FeAl alloy samples even after 5 h of milling but magnetization decreases as the milling time increases. The reason for the same is due to the shocks and fracturing of the Al atoms embedded in the sites of Fe and as a result of which Fe–Fe nearest neighbors decreases. Secondly, with the increase in milling time, the particle size and the number density of equiatomic BCC Fe₅₀Al₅₀ grains decrease while the volume of grain boundary containing a solid solution of BCC FeAl and concentration of Al in a solid solution of BCC FeAl at the grain boundary increases as a result of which magnetization decreases. The shift in the binding energy of Fe_2p and Al_2p core level towards higher binding energy also supports the alloy formation after milling.

Titanium dioxide (TiO₂) film was deposited by the direct current pulse magnetron sputtering technique. Then the surface of TiO₂ film was implanted by the N ion beam at room temperature. Through this way, N-doped TiO₂ (N–TiO₂) film was obtained and the band gap of N–TiO₂ film was decreased to 2.97 eV. XPS result revealed that N ion was doped into TiO₂ film as Ti–N and Ti–NO bonds. N ion was substitutionally/interstitially doped into TiO₂ crystal lattice and Ti–N bond was formed. N ion was doped into amorphous TiO₂ and Ti–ON bond was formed. The polycrystal TiO₂ film could result in that more N ion was substitutionally/interstitially doped into TiO₂ crystal lattice, which could effectively narrow the band gap of N–TiO₂ film. This work provides a potential N doping method which could be applied commercially.

In this study, a leaf-like ${\mathrm{\text{Cu}}}_2\mathrm{\text{O}}/\mathrm{\text{CuO}}$ mixed phase nanosheets array was successfully prepared by anodization. XRD, EDS, and XPS analysis confirmed the formation of ${\mathrm{\text{Cu}}}_2\mathrm{\text{O}}/\mathrm{\text{CuO}}$ mixed phase nanostructures. SEM images indicate that the fabricated ${\mathrm{\text{Cu}}}_2\mathrm{\text{O}}/\mathrm{\text{CuO}}$ mixed phase nanosheets almost grow vertically on the substrate. The average height of nanosheets is approximately 500 nm. The optical absorption of the mixed phase covers the entire wavelength region of visible light and a little part of the near-infrared region of short wavelength.