Search

The cohesive zone model (CZM) is introduced in the surface acoustic wave (SAW) technique to characterize the interfacial adhesion property of the low- k thin film deposited on the Silicon substrate. The ratio of the two parameters in the CZM, the maximum normal traction and normal interface characteristic length, is derived to evaluate the interfacial adhesion properties quantitatively. In this study, the adhesion criterion to judge the adhesion property is newly proposed by the CZM-SAW technique. The criterion determination processes of two kinds of film, dense and porous Black Diamond with different film thicknesses, are presented in this paper. The interfacial adhesion properties of the dense and porous Black Diamond films with different thicknesses are evaluated by the CZM-SAW technique quantitatively and nondestructively. The quantitative adhesion properties are obtained by fitting the experimental dispersion curves with maximum frequency up to 220 MHz with the theoretical ones. Results of the nondestructive CZM-SAW technique and the destructive nanoscratch exhibit the same trend in adhesion properties, which means that the CZM-SAW technique is a promising method for determining the interfacial adhesion. Meanwhile, the adhesion properties of the detected samples are judged by the determined criterion. The test results show that different test film materials with different film thicknesses ranging from 300 nm to 1000 nm are in different adhered conditions. This paper exhibits the advantage of the CZM-SAW technique which can be a universal method to characterize the film adhesion. [ABSTRACT FROM AUTHOR]

We have systematically investigated the optoelectrical properties of As 33 Se 67-x Sn x (x = 0, 2, 4 and 6) thin films. The optical parameters have been determined using transmission spectra in the spectral range (400 nm–2000 nm). Addition of Sn to As 33 Se 67 thin films was found to affect the refractive index, n , extinction coefficient, k , and all related parameters. The dispersion of the refractive index has been discussed in terms of the single-oscillator model. The real and imaginary parts of dielectric constants ε 1 & ε 2 were used in order to study the dielectric behavior and to obtain many optelectrical parameters such as high-frequency dielectric constant, ε ∞ , lattice dielectric constant, ε L , plasma frequency, ω p , relaxation time, τ , optical mobility, μ opt , and optical resistivity ρ opt . All of ε 1 , ε 2 , ε ∞ , ε L , ω p , and optical conductivity, σ , were increased with increasing Sn content, whereas τ , μ opt , ρ opt and optical electronegativity, η opt were decreased with increasing Sn percent in the studied films. A red shift in the transmittance edge has been observed due to Sn incorporation. The decrease of the estimated optical energy gap, E g , stems from the difference of the binding energies of various bonds. Additionally, the nonlinear optical susceptibility χ (3) and the nonlinear refractive index n 2 were estimated from linear optical parameters using semi-empirical relations. Moreover, the effect of Sn incorporation on the non-linear optical parameters has been also discussed. [ABSTRACT FROM AUTHOR]

Highlights: [•] Interactions of discharges in heptane with thin films of copper, aluminum and iron, or show specific behaviors. [•] At low impact energy, melting of surface is not always assured and surface stress may be invoked to explain how the shape of the surface is defined. [•] At intermediate energy, melting occurs, leading to the synthesis of external beads by Marangoni's convection. [•] At high energy, the shape of the impact is defined by the pressure release when the discharge stops. [•] Multilayers can be designed to improve the way the energy of the plasma is deposited. [ABSTRACT FROM AUTHOR]

Abstract: Aqueous synthesis of CdS quantum dots (QDs) using thiolactic acid (TLA) as a capping agent was reported. These QDs exhibited excellent colloidal and photostability over a span of 2years and showed intense broadband and almost white photoluminescence suitable for solid state lighting devices. The photoluminescence (PL) property of the aqueous CdS QDs is optimized by adjusting various processing parameters. The highest quantum yield (QY) achieved for TLA capped CdS QDs of average size 3.5nm was ∼50%. Luminescence lifetime measurements of CdS–TLA QDs indicated longer lifetimes and a larger contribution of the surface-related emission, indicating removal of quenching defects. [Copyright &y& Elsevier]

Abstract: The electronic structures of oligomeric and polymeric -cyclopentadienyl (Cp)–indium complexes were examined by tight-binding band calculations. On the basis of the band structures, we discuss the delocalization of electrons along the axis of the polymer chain. In order to discuss the application of this polymeric complex to nano/molecular electronic devices, it is important to consider its interaction with a metal electrode. Therefore, we also examined the electronic structures of an oligomeric Cp–In complex adsorbed on a metal slab (Pt or Au). [Copyright &y& Elsevier]

Abstract: We present a complete surface-potential-based compact model of dynamically depleted (DD) SOI MOSFETs. The surface potential equation of DD-SOI MOSFETs was reconditioned to avoid the unphysical behaviors near the flat-band voltage. In order to capture the dynamic depletion effect, the coupling equation for the front and back surface potentials was reformulated to include the back gate effect, which is not available in other surface-potential-based DD-SOI compact models. The new formulation of surface potential and coupling equations was verified by comparing with numerical computations combining the Pao–Sah double integral based formulation and the exact coupling equation. To obtain explicit expressions for the terminal charges and drain current, a new symmetric linearization method has been proposed. The complete model, PSP-SOI DD is implemented in the context of the PSP and PSP-SOI PD models and includes all the secondary effects, floating body simulation capability, etc. The new model has been extensively verified with 2D TCAD simulation results and accurately captures the manifestation of the dynamic depletion effect observed in the device characteristics. [Copyright &y& Elsevier]

Abstract: CdSe x Te1− x thin films were brush plated on titanium and conducting glass substrates from the precursors at different substrate temperatures in the range of 30–80°C. X-ray diffraction studies indicated the films to possess hexagonal structure irrespective of composition. The strain and dislocation density decrease with increase of substrate temperature. The crystallite size increased from 30 to 100nm as the substrate temperature increased. The resistivity of the films decreased with increase of substrate temperature. The carrier density and mobility increased with substrate temperature. Optical band gap of the films varied in the range of 1.45–1.72eV. Higher photosensitivity was obtained compared to earlier reports. [Copyright &y& Elsevier]

Abstract: Lightly Dy-doped CdO thin films (molar 0.5%, 1%, 2%, and 2.5%) have been prepared by a vacuum evaporation method on glass and Si wafer substrates. The prepared films were characterised by X-ray fluorescence, X-ray diffraction, UV–vis-NIR absorption spectroscopy, and dc-electrical measurements. Experimental data indicate that Dy3+ doping slightly stretchy-stresses the CdO crystalline structure and changes the optical and electrical properties. The bandgap of CdO was suddenly narrowed by about 20% due to a little doping with Dy3+ ions. Then, as the Dy doping level was increased, the energygap was also increased. This variation was explained by the effect of Burstein–Moss energy shift (or bandgap widening effect) together with a bandgap shrinkage effect. The electrical behaviour of the samples shows that they are degenerate semiconductors. However, the 2% Dy-doped CdO sample shows an increase in its mobility by about 3.5 times, conductivity by 35 times, and carrier concentration by 10 times relative to undoped CdO film. From transparent conducting oxide point of view, Dy is sufficiently effective for CdO doping. [Copyright &y& Elsevier]

Abstract: The water blast attenuating performance of a polymer layer coated onto floating structures has been experimentally investigated. A series of contrastive live fire tests were conducted on a rectangular metal box before and after coating a layer of polymer on its outer hull. The blast responses of the box and water pressure near the wet surface were monitored and analyzed. Test results show that the transmitted impulse at the initial FSI stage can be reduced by almost 50%, owing to the rubber wall flexibility. Consequently, both acceleration and strain peaks of the box induced by the first shock wave can be effectively reduced. Further shock response spectrum analysis indicates that the coating performs like a low pass filter with cutoff frequency at about 50 Hz. Response components higher than 50 Hz can be attenuated effectively, but for components lower than the cutoff frequency, the attenuating effect is limited. [Copyright &y& Elsevier]

Abstract: Nano-indenter as a technique for characterization and evaluation of mar/scratch resistance of a two component automotive clear coat is used. Different responses of the coatings to the marring stress and critical forces are discussed. The plastic deformation compared to the elastic part and the damage width is decreased by adding nano-silica in the coatings formulation. [Copyright &y& Elsevier]

Abstract: Interaction of Nd:YAG laser, operating at 1064 or 532nm wavelength and a pulse duration of 40ps, with AISI 1045 steel was studied. Surface damage thresholds were estimated to be 0.30 and 0.16J/cm2 at the wavelengths of 1064 and 532nm, respectively. The steel surface modification was studied at the laser energy density of 10.3J/cm2 (at 1064nm) and 5.4J/cm2 (at 532nm). The energy absorbed from Nd:YAG laser beam is partially converted to thermal energy, which generates a series of effects, such as melting, vaporization of the molten material, shock waves, etc. The following AISI 1045 steel surface morphological changes and processes were observed: (i) both laser wavelengths cause damage of the steel in the central zone of irradiated area; (ii) appearance of a hydrodynamic feature in the form of resolidified droplets of the material in the surrounding outer zone with 1064nm laser wavelength; (iii) appearance of periodic surface structures, at micro- and nano-level, with the 532nm wavelength and, (iv) development of plasma in front of the target. Generally, interaction of laser beam with the AISI 1045 steel (at 1064 and 532nm) results in a near-instantaneous creation of damage, meaning that large steel surfaces can be processed in short time. [Copyright &y& Elsevier]

Abstract: Indium-doped cadmium oxide films were obtained by mixing cadmium oxide and indium oxide precursor solutions by the sol–gel technique. The indium atomic concentrations in solution (x) studied were 0, 2, 5 and 10at%. The films were sintered at two different sintering temperatures (T s) 350 and 450°C, and after that annealed in a 96:4 N2/H2 gas mixture atmosphere at 350°C. X-ray diffraction patterns showed that all films sintered at T s=350°C only consisted of cadmium oxide crystals. The films sintered at T s=450°C consisted of cadmium oxide crystals also; however, for the highest indium atomic concentration (10at%) the formation of cadmium indate oxide crystals was evident. All films show high optical transmission (>85%) and an increase of the direct band gap value from 2.4 to 3.1eV, as the indium atomic concentration in solution increases. The minimum resistivity value obtained was 6.3×10−4 Ωcm for the films with x=5at%, T s=450°C and annealed at 350°C. [Copyright &y& Elsevier]

Abstract: The influence of oxygen partial pressure during the deposition of piezoelectric strontium-doped lead zirconate titanate thin films is reported. The thin films have been deposited by RF magnetron sputtering in an atmosphere of high purity argon and oxygen (in the ratio of 9:1), on platinum-coated silicon substrates (heated to 650°C). The influence of oxygen partial pressure is studied to understand the manner in which the stoichiometry of the thin films is modified, and to understand the influence of stoichiometry on the perovskite orientation. This article reports on the results obtained from films deposited at oxygen partial pressures of 1–5mTorr. The thin films have been studied using a combination of X-ray photoelectron spectroscopy (XPS), glancing angle X-ray diffraction (GA-XRD), and atomic force microscopy (AFM). XPS analysis highlights the marked influence of variations in oxygen pressure during sputtering, observed by variations in oxygen concentration in the thin films, and in some cases by the undesirable decrease in lead concentration in the thin films. GA-XRD is used to study the relative variations in perovskite peak intensities, and has been used to determine the deposition conditions to attain the optimal combination of stoichiometry and orientation. AFM scans show the marked influence of the oxygen partial pressure on the film morphology. [Copyright &y& Elsevier]

Abstract: This article discusses the formation and detailed materials characterisation of nickel silicide thin films. Nickel silicide thin films have been formed by thermally reacting electron beam evaporated thin films of nickel with silicon. The nickel silicide thin films have been analysed using Auger electron spectroscopy (AES) depth profiles, secondary ion mass spectrometry (SIMS), and Rutherford backscattering spectroscopy (RBS). The AES depth profile shows a uniform NiSi film, with a composition of 49–50% nickel and 51–50% silicon. No oxygen contamination either on the surface or at the silicide–silicon interface was observed. The SIMS depth profile confirms the existence of a uniform film, with no traces of oxygen contamination. RBS results indicate a nickel silicide layer of 114nm, with the simulated spectra in close agreement with the experimental data. Atomic force microscopy and transmission electron microscopy have been used to study the morphology of the nickel silicide thin films. The average grain size and average surface roughness of these films was found to be 30–50 and 0.67nm, respectively. The film surface has also been studied using Kikuchi patterns obtained by electron backscatter detection. [Copyright &y& Elsevier]

Abstract: This article reports on the in situ analysis of nickel silicide (NiSi) thin films formed by thermal processing of nickel thin films deposited on silicon substrates. The in situ techniques employed for this study include micro-Raman spectroscopy (μRS) and X-ray diffraction (XRD); in both cases the variations for temperatures up to 350°C has been studied. Nickel silicide thin films formed by vacuum annealing of nickel on silicon were used as a reference for these measurements. In situ analysis was carried out on nickel thin films on silicon, while the samples were heated from room temperature to 350°C. Data was gathered at regular temperature intervals and other specific points of interest (such as 250°C, where the reaction between nickel and silicon to form Ni2Si is expected). The transformations from the metallic state, through the intermediate reaction states, until the desired metal–silicon reaction product is attained, are discussed. The evolution of nickel silicide from the nickel film can be observed from both the μRS and XRD in situ studies. Variations in the evolution of silicide from metal for different silicon substrates are discussed, and these include (100) n-type, (100) p-type, and (110) p-type silicon substrates. [Copyright &y& Elsevier]

Abstract: In this study, the microstructure and the deformation mechanisms of TiN, CrN and multilayer TiN/CrN thin films on silicon substrates were investigated. Cross-sectional lamellas of nanoindents were prepared by focused ion beam milling to observe by transmission electron microscopy the microstructure of the as-deposited and deformed materials. TiN film exhibits nanocrystalline columns, whereas CrN shows large grains. The TiN/CrN multilayer presents microstructural features typical for both materials. A film hardness of 16.9GPa for CrN, 15.8GPa for TiN and 16.6GPa for TiN/CrN was found by the nanoindentation. Reduced modulus recorded for TiN and CrN reference coatings were 221.54 and 171.1GPa, respectively, and 218.6GPa for the multilayer coating. The deformation mechanisms were observed via in-situ scanning electron microscope nanoindentation. The TiN thin film showed short radial cracks, whereas CrN deformed through pile-up and densification of the material. For TiN/CrN multilayer pile-up and cracks were found. Transmission electron microscopy observations indicated that TiN deforms through grain boundary sliding and CrN via densification and material flow. The deformation mechanism observed in TiN/CrN multilayer was found to be a mixture of both modes. [Copyright &y& Elsevier]

Abstract: Transparent and highly conducting gallium zinc oxide (GZO) films were successfully deposited by RF sputtering at room temperature. A lowest resistivity of ∼2.8×10−4 Ωcm was achieved for a film thickness of 1100nm (sheet resistance ∼2.5Ω/□), with a Hall mobility of 18cm2/Vs and a carrier concentration of 1.3×1021 cm−3. The films are polycrystalline with a hexagonal structure having a strong crystallographic c-axis orientation. A linear dependence between the mobility and the crystallite size was obtained. The films are highly transparent (between 80% and 90% including the glass substrate) in the visible spectra with a refractive index of about 2, very similar to the value reported for the bulk material. These films were applied to single glass/TCO/pin hydrogenated amorphous silicon solar cells as front layer contact, leading to solar cells with efficiencies of about 9.52%. With the optimized deposition conditions, GZO films were also deposited on polymer (PEN) substrates and the obtained results are discussed. [Copyright &y& Elsevier]

Abstract: ZnS thin films with a c-axis preferred orientation have been prepared by sulfurizing the RF reactive sputter deposited ZnO thin films at 500°C in sulfur vapor. These thin films have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV–visible transmission spectra and Auger electron spectroscopy (AES). It is found that the degree of c-axis orientations of ZnO and ZnS thin films increases with enhancing RF power. Also, the sulfurized thin films have markedly greater grains than the as-deposited films, mainly due to recrystallization of ZnS in sulfur vapor. The grain size for the ZnS films increases from ∼200 to ∼500nm with enhancing RF power from 80 to 120W. A reason for this is that in the case of the greater RF power, high compactness of the films will be very beneficial to the grain growth. Additionally, the excess sulfur can be absorbed on the grain surface of the ZnS film produced by 22h sulfidation. This will cause the great broadening of absorption edge in the optical transmittance. [Copyright &y& Elsevier]

Abstract: A multilayer film of Mg and Ni was prepared by dc/ac magnetron sputtering and annealed below 623K in vacuum to obtain polycrystalline Mg2Ni thin films. The phase transformation during heating process and optical switching properties of the films were investigated. The influence of the original crystalline state of Mg2Ni films on optical switching properties such as transmission, optical band gaps and the cycle times was discussed. The indirect optical band gaps of the fully hydrogenated amorphous Mg2Ni films were estimated by linear extrapolation. [Copyright &y& Elsevier]

Abstract: The effect of the ratio of fluctuation field (H f) to coercivity (H c) on the temperature coefficient of coercivity [α(H c)] was investigated for Co55Cr15.5Pt28B1.5/Co63Cr37/Cr, Co69Cr19Pt9Ta3/Cr, and Co86Cr10Ta4/Cr thin films (longitudinal recording media) with very small average grain volume (V phy). α(H c) increases markedly with increase in temperature between near 250 and 350K for Co55Cr15.5Pt28B1.5/Co63Cr37/Cr thin films. α(H c) is approximately proportional to the ratio H f/H c for all thin films, as in the case of advanced data backup tapes prepared from ultrafine particles. α(H c) and the ratio H f/H c increase as V phy decreases. Smaller H f/H c values are necessary for small α(H c) values, which is very important for the thermal stability of high-density recording media with very small V phy. [Copyright &y& Elsevier]

Abstract: A comparative study of the reaction characteristics between molten tin and both as-plated and heat-treated Ni–P coatings was carried out, with a specific focus on the stability of the Ni3P intermetallic layer and its effects on the subsequent reaction. It was found that a continuous layer of Ni3P may be formed on both types of Ni–P during the interfacial reaction, despite the fact that heat-treated Ni–P is a two-phase mixture of Ni3P and Ni. The Ni3P formed on the heat-treated Ni–P was thinner than that on as-plated Ni–P. A mass conservation analysis of P revealed that no or limited P was lost into the molten tin when the Ni3P layer was thin, whereas a significant loss of P took place as the Ni3P thickness increased. It is proposed that the Ni3P phase is stable and may not undergo chemical decomposition during the interfacial reaction. The loss of P to the molten tin observed in the present study is most likely due to the crumbling of Ni3P particles into the liquid phase, as a result of the enhanced mass transport due to use of thin copper wire substrates rather than a planar surface. Finally, the results show that the Ni3P phase cannot act as an effective barrier layer to the attack of molten tin toward the substrate. Defects in the Ni3P were found to allow localized penetration of molten tin. [Copyright &y& Elsevier]

Abstract: The electrochromic and photocatalytic properties of vanadium-doped tungsten trioxide thin films prepared at room temperature (300K) by the electron beam evaporation technique are reported in this paper. The vanadium to tungsten ratio (V/W) in these films are 0.003, 0.019, 0.029 and 0.047. The optical band gap of the vanadium-doped tungsten oxide (WO3) thin film initially increases from 3.16 to 3.28eV for V/W ratio 0.003 then decreases to 3.15eV for V/W ratio 0.047. These vanadium-doped films switch between neutral gray and transparent states. The coloration efficiency (CE) decreases from 82cm2 C−1 (pure WO3) to 27cm2 C−1 for the film containing V/W ratio 0.047. The photocatalytic activity has enhanced with vanadium doping and maximum activity of 15% (percentage change in optical density of methylene blue due to photo degradation) has been observed for the film containing V/W ratio of 0.019. The Kelvin probe measurements show that the work function of pure WO3 films is 4.07eV and vanadium doping initially increases the work function to 4.19eV for V/W ratio 0.019 and then decreases it to 3.97eV for film with V/W ratio 0.047. [Copyright &y& Elsevier]

Abstract: CrN/CN x nano-scale multilayered films have been grown on both Si(100) and high speed steel substrates (HSS) by closed-field unbalanced magnetron sputtering. Designed experimental parameters enabled an evaluation of the effects of negative substrate bias voltage (V b), and bi-layer thickness λ (by changing substrate rotation rate) during deposition on the structural and mechanical properties of reactively sputtered CrN/CN x multilayer thin films. In all cases, the CN x layers prepared at OEM=55% were amorphous independent of V b, while the microstructures of the CrN layers were dependent primarily on V b. The CrN layers showed a mixed structure phase consisting of CrN, Cr2N, and Cr at V b =−(40–120)V. At higher V b values (−140V or above), the Cr2N phase was dominant along with low CrN phase content. AFM measurements revealed that the root-mean-square (rms) surface roughness of the CrN/CN x film was 2.5nm at V b =−200V whereas the rms values were about 9.5–3.3 2nm for lower V b values of −(40–180V). By nanoindentation measurements, a maximum hardness of ∼36GPa was observed in a film prepared at V b =−140V. The improved mechanical properties of the CrN/CN x multilayer films are correlated to the phase formation during deposition. [Copyright &y& Elsevier]

Abstract: In conventional or macroscale milling, appropriate physical vapour deposition (PVD) coatings can be used to improve machining performance, promote the use of higher cutting speeds and facilitate dry machining or the use of minimum quantity lubrication (MQL). When micro tools (1–999μm in diameter) are used in milling, the undeformed chip thickness is usually very small and comparable to the cutting edge radius. This condition determines the effective rake angle and hence plays a significant role in the mechanics of micro machining. The differences between macro and microscale machining influence process factors such as cutting interface temperatures, forces, strains and strain rates. The mechanisms through which coatings protect cutting tools are influenced by such process conditions. Additionally, due to the size of micro tools applying coatings evenly around the cutting edges is a technological challenge. Despite these new challenges, there is hardly any work reported in literature dedicated to the selection of hard coatings for micro machining of tool steels. The work reported in this paper identified coating wear mechanisms in micro milling of hardened tool steels. A wide range of PVD coatings were evaluated based on multiple criteria of tool wear, surface finish and burr size. The results clearly show that compared to other coatings or uncoated fine grain carbide tools, TiN coatings offer the best performance in terms of tool wear reduction and improvement in quality of machined surface. [Copyright &y& Elsevier]

Abstract: The transient growth and thinning of the passive film on iron was investigated in ethylenediaminetetraacetic acid, disodium salt (EDTA) containing borate buffer solutions of pH 8.4 using real-time spectroscopic ellipsometry under potentiostatic control. EDTA effectively suppressed the formation of the outer layer of the passive film, thereby rendering the barrier layer amenable to direct examination. It was shown that the barrier layer growth was completed in about 10s upon potential stepping in the anodic direction. On the other hand, the thinning of the barrier oxide layer upon potential stepping in the cathodic direction occurred at a rate that was two orders in magnitude lower than the growth rate. The steady-state barrier layer thickness varied linearly with applied potential, whereas the steady-state current density did not depend on the formation potential. These spectroscopic ellipsometric measurements are qualitatively explained by the point defect model (PDM). [Copyright &y& Elsevier]

Abstract: Mesoporous alumina layers have attracted attention for their potential use in ultrafiltration of salts, as a heterogeneous catalyst support, an adsorbent in environmental cleanup, and in petroleum refinement. The ability to control the fast hydrolysis rate of the inorganic precursors using simple and inexpensive routes is important for that potential to be realized. Herein, we introduce a novel and facile route to synthesize mesoporous alumina thin films from the combination of inexpensive and commercially available copolymer with aluminum chloride or nitrate (salts) in an EtOH–surfactant–NH3 ·H2O–salts (EsNs) system through the evaporation-induced self-assembly (EISA) method. Mesoporous alumina layers obtained utilizing the EsNs system have ordered and tunable pore structures. The ability to easily control the mesophases of the alumina layers within a short time provides distinct advantages over previously reported synthesis procedures. Most importantly, we demonstrate that the binding of surfactant and NH3 ·H2O for the formation of hydrogen bond between them in the EsNs system controls the fast hydrolysis rate of the inorganic species. This allows for the synthesis of nanocrystalline alumina layers via the aluminum oxo-clusters’ assembly with the surfactant. Such simple route may be applied in the synthesis of other non-silica mesostructured oxides. [Copyright &y& Elsevier]

Abstract: Nd3+/V5+-cosubstituted Bi4Ti3O12 (Bi3.15Nd0.85Ti2.97V0.03O12, BNTV) thin films are prepared on Pt/Ti/SiO2/Si(100) substrates by a chemical solution deposition (CSD) technique. The structure and surface morphology of the films are analyzed using X-ray diffraction (XRD), Raman spectroscopy and scanning electron microscopy, respectively. The electrical properties of BNTV films are investigated as a function of annealing temperatures. The remanent polarization, dielectric constant and capacitance of the BNTV thin films increase with the increase of annealing temperatures in the range of 650–750°C. After annealing at 750°C, the BNTV film exhibits good polarization fatigue characteristics at least up to 1×1010 switching cycles at a frequency of 100kHz and excellent retention properties up to 1×105 s. [Copyright &y& Elsevier]

Abstract: In this study, high quality of Al-doped ZnO (AZO) thin films were deposited at different oxygen argon ratio by direct current (DC) reactive magnetron sputtering using a Zn target (99.99%) containing Al of 1.5%. The obtained films were characterized and analyzed by X-ray diffraction (XRD) and ultraviolet–visible and infrared light spectrophotometer. The electrical properties had been investigated by van der Pauw method. It was also found that oxygen argon (O2/Ar) ratio had great influence on the properties. The results show that AZO thin films are polycrystalline with a preferred (002) orientation. The film stress increases with increasing O2/Ar ratio. The lowest resistivity of 1.306×10−3 Ωcm was obtained for the AZO thin films prepared at O2/Ar ratio of 0.3/27. Hall mobility decreases with increasing the O2/Ar ratio. With increasing O2/Ar ratio, the transmittance of the AZO thin films has no evident changes. There is a strong absorption in the ultraviolet region. The optical absorption edge is found to shift to the longer wavelength with the increase of O2/Ar ratio. The measurements show that there is a striking Seebeck effect in the AZO thin films, and their thermoelectromotive force is linearly increased with increasing temperature difference (ΔT). With increasing O2/Ar ratio and resistance of samples, thermoelectric power (TEP) decreases. [Copyright &y& Elsevier]

Abstract: In this work, the main problems concerning the scattering of light by real surfaces and films are presented in view of results obtained with the bidirectional reflection distribution function (BRDF) method and optical profilometry (OP). The BRDF and OP studies, being complementary to the atomic force microscopy (AFM), allow one to get information about surface topography. From the optical data, the surface power spectral density (PSD) functions for absorbing and transparent rough films have been found. Both functions have been evaluated from the Fourier transform (FT) of the surface profiles. The usefulness of BRDF-and OP methods in characterization of real surfaces is demonstrated when analyzing the optical data obtained for metallic TiN-and organic PVK thin films deposited on various substrates. [Copyright &y& Elsevier]

Abstract: In order to improve a critical temperature (T c) of LaBa2Cu3O y (LaBCO) thin films for achieving a high irreversibility field, we investigated the vapor–liquid–solid (VLS) technique with various composition ratios of Ba/Cu in a liquid layer as growth solvent. As a result, we achieved the VLS-LaBCO thin films with excellent crystallinity and observed a spiral growth consisted of the wide terrace with a width of about 300nm. Moreover, the orthorhombicity and the T c onset of VLS-LaBCO thin films increased with increasing Ba/Cu ratio in the liquid layer. [Copyright &y& Elsevier]

Abstract: A new series of ABO3-type REBiO3 have been derived from the system Bi2O3–RE2O3, in which cubic RE2O3 stabilize cubic structure of δ-Bi2O3, enabling the formation of REBiO3 at relatively low temperature range. A chemical solution deposition (CSD) route has been used to deposit epitaxial thin films of REBiO3. The crystal lattice, chemical stability, texture development, combined with the successful deposition of high quality superconducting layer demonstrate that the newly developed compounds may play as potential alternatives of buffer layer materials for REBCO-based coated conductors. [Copyright &y& Elsevier]

Abstract: The LiCoO2 cathode coating on a flexible stainless steel has been successfully formed by using sol–gel process and spin-coating technique. The microstructures and electrochemical performance of this LiCoO2 cathode were characterized by using an X-ray diffractometer (XRD), a scanning electron microscope (SEM) and electrochemical methods. After annealing at ca. 500 °C, the results of XRD showed that the LiCoO2 gel was crystallized and the crystallized thin films show hexagonal phase with a space group R 3¯ m. When the annealing temperatures kept at 700 °C, the stainless steel substrate was oxidized and subsequently reacted with LiCoO2. Such a reaction also destabilized the structure of LiCoO2. The SEM observation indicated that the average grain size of films increased with increasing temperature and the thickness of spin-coated films is ca. 1–3 μm. The LiCoO2 thin films prepared from sol–gel process and spin-coating exhibit reversible electrochemical behavior of Li+ intercalation and de-intercalation reactions. [Copyright &y& Elsevier]

Abstract: Scandia-stabilized zirconia (SSZ) thin films, ~400 nm thick, were deposited on sapphire substrate by a pulsed-laser deposition (PLD) method. Their structural and transport properties were studied by means of X-ray diffraction and electrical conductivity measurements. The in-plane conductivities of thin films were measured and compared to that of the bulk sample. Although the decrease in ionic conductivity near phase transition temperature (550 °C) was still shown in the case of the 10SSZ film, the conductivity drop was much smaller and less abrupt compared to that of bulk samples. With 1 mol% Y2O3 or CeO2 doping, the conductivity curves became linear. However, the conductivity was reduced from that of the undoped 10SSZ film. [Copyright &y& Elsevier]

Abstract: Undoped ZnO thin films of different thicknesses were prepared by r.f. sputtering in order to study the thickness effect upon their structural, morphological, electrical and optical properties. The results suggest that the film thickness seems to have no clear effect upon the orientation of the grains growth. Indeed, the analysis with X-ray diffraction show that the grains were always oriented according to the c(002)-axis perpendicular to substrate surface whatever the thickness is. However, the grain size was influenced enough by this parameter. An increase in the grain size versus the thickness was noted. For the electrical properties, measurements revealed behaviour very dependent upon thickness. The resistivity decreased from 25 to 1.5×10−3 Ωcm and the mobility increased from 2 to 37cm2 V−1 s−1 when the thickness increased from 70 to 1800nm while the carrier concentration seems to be less affected by the film thickness and varied slightly remaining around 1020 cm−3. Nevertheless, a tendency to a decrease was noticed. This behaviour in electrical properties was explained by the crystallinity and the grain size evolution. The optical measurements showed that all the samples have a strong transmission higher than 80% in the visible range. A slight shift of the absorption edge towards the large wavelengths was observed as the thickness increased. This result shows that the band gap is slightly decreases from 3.37 to 3.32eV with the film thickness vary from 0.32 to 0.88μm. [Copyright &y& Elsevier]

Abstract: Ti–Ni–Cu shape-memory alloy (SMA) thin films were sputter-deposited on heated polyimide substrates. Ti–Ni–Cu films deposited at substrate temperatures of 543 and 583 K were found to be crystalline. Especially, a Ti48Ni29Cu23 film deposited at 583 K exhibited a high martensitic transformation temperature above room temperature and a narrow transformation temperature range, which enable the film to be used at room temperature. Double-beam cantilevers made of 8 μm thick Ti48Ni29Cu23 films deposited on 12.5 and 25 μm thick polyimide substrates displayed a repeatable shape-memory effect by a battery of 1.5 V and it was verified that the composite film consisting of an 8 μm thick Ti48Ni29Cu23 film and a 25 μm thick polyimide film is capable of moving 0.18 g wings of a dragonfly toy up and down. These results offer the prospect for using an SMA/polyimide actuator as a convenient small actuator, which will find wide-ranging applications. [Copyright &y& Elsevier]

Abstract: By means of X-ray photoemission spectroscopy and low energy electron diffraction, we show that it is possible to grow good quality thin epitaxial CoO films on Fe(001) substrates, through deposition in oxygen atmosphere. In particular, the composition and the structure of CoO(001)/Fe(001) bilayer systems and Fe(001)/CoO(001)/Fe(001) trilayer systems have been investigated by monitoring the evolution of the chemical interactions at the interfaces as a function of CoO thickness and growth temperature. We observe the presence of Fe oxides at the CoO/Fe interface and of a thin layer of metallic cobalt at the upper Fe/CoO interface of trilayer systems. [Copyright &y& Elsevier]

Abstract: We employ textured α-Cr2O3 thin films as templates for growth of α-Al2O3 by reactive inductively coupled plasma magnetron sputtering. The texture of the template has a strong influence on the nucleation and growth of α-Al2O3. Extended growth of α-Al2O3 at a substrate temperature of 450 °C is obtained using a predominantly [101̄4]-textured α-Cr2O3 template layer, while only limited α-Al2O3 nucleation is seen on a [0001]-textured α-Cr2O3 template. [Copyright &y& Elsevier]

Abstract: Fabrication of vis-responsive anatase thin films with enhanced UV-sensitivity was attained on an ITO pre-coated glass substrate by applying two precursor solutions involving Ti complexes of oxalic acid and EDTA. The transparent and crack-free thin films were characterized by XRD, XPS, UV–vis and FE-SEM observation. The highest sensitivity to UV light of the vis-responsive film, whose photocatalytic activity was measured by the decomposition rate of methylene blue, was four times as compared with that formed by a sol–gel method under the same conditions. The vis-responsive films showed a characteristic absorption band at around 480nm. [Copyright &y& Elsevier]

Abstract: The conditions of the electrodeposition of a thin film of polycrystalline ZnSe phase on copper substrate from aqueous baths were studied. The electrochemical behavior of Zn2+ and H2SeO3 species was investigated using cyclic voltammetry. Thin films were deposited potentiostatically on copper substrate and the influence of deposition parameters such as deposition potential, H2SeO3 and ZnSO4 concentration, and temperature of bath on the crystallinity and on the chemical composition of the film is discussed. The ZnSe layers were characterized by X-ray diffraction, X-ray energy dispersive spectroscopy and scanning electron microscopy. [Copyright &y& Elsevier]

Abstract: In this article, we perform a preliminary study to assemble micro-size thermoelectric devices with low-cost fabrication by a preparation of nanoparticles and their thin films. Bi0.4Te3.0Sb1.6 nanoparticles with an average size of approximately 50nm are fabricated by a beads-milling method. The nanoparticle solution is prepared by mixing with toluene and a surfactant, and thin films with 1μm thick are deposited on Al2O3 substrates by a printing method. The thin films are sintered at temperatures ranging from 300 to 500°C for 60min in hydrogen ambient. We investigate the thin film structures and the thermoelectric properties at room temperature. As the sintering temperature increases, hexagonal-shaped crystals are grown on the film surface while the atomic composition is almost constant throughout all the sintering temperatures. The XRD patterns indicate that all the nanoparticle thin films are found to mostly exhibit the same XRD intensities and have multiple peaks correspond to each other. The in-plane electrical conductivity of the thin films increases but the Seebeck coefficient decreases as the sintering temperature increases. As a result, the best performance of the thermoelectric power factor of 1.3μW/(cmK2) is achieved at a sintering temperature of 350°C. [Copyright &y& Elsevier]

Abstract: ZnO films with different morphologies were deposited on the ITO-coated glass substrate from zinc nitrate aqueous solution at 65°C by a seed-layer assisted electrochemical deposition route. The seed layers were pre-deposited galvanostatically at different current densities (i sl) ranging from −1.30 to −3.0mA/cm2, and the subsequent ZnO films had been done using the potentiostatic technique at the cathode potential of −1.0V. Densities of nucleation centers in the seed layers varied with increasing the current density, and the ZnO films on them showed variable morphologies and optical properties. The uniform and compact nanocrystalline ZnO film with (002) preferential orientation was obtained on seed layer that was deposited under the current density (i sl) of −1.68mA/cm2, which exhibited good optical performances. [Copyright &y& Elsevier]

Abstract: Although the fabrication of tin disulfide thin films by SILAR method is quiet common, there is, however, no report is available on the growth of SnS thin film using above technique. In the present work, SnS films of 0.20μm thickness were grown on glass and ITO substrates by SILAR method using SnSO4 and Na2S solution. The as-grown films were smooth and strongly adherent to the substrate. XRD confirmed the deposition of SnS thin films. Scanning electron micrograph revealed almost equal distribution of the particle size well covered on the surface of the substrate. EDAX showed that as-grown SnS films were slightly rich in tin component while UV–vis transmission spectra exhibited high absorption in the visible region. The intense and sharp emission peaks at 680 and 825nm (near band edge emission) dominated the photoluminescence spectra. [Copyright &y& Elsevier]

Abstract: Ga and N co-doped p-type ZnO thin films were epitaxially grown on sapphire substrate using magnetron sputtering technique. The process of synthesized Ga and N co-doped ZnO films was performed in ambient gas of N2O. Hall measurement shows a significant improvement of p-type characteristics with rapid thermal annealing (RTA) process in N2 gas flow, where more N acceptors are activated. The film rapid thermal annealed at 900°C in N2 ambient revealed the highest carrier concentration of 9.36×1019 cm−3 and lowest resistivity of 1.39×10−1 Ωcm. In room and low temperature photoluminescence measurements of the as grown and RTA treated film, donor acceptor pair emission and exciton bound to acceptor recombination at 3.25 and 3.357eV, respectively, were observed. [Copyright &y& Elsevier]

Abstract: Cuprous oxide films were deposited on glass substrates using dc magnetron sputtering technique by sputtering of pure copper target in a mixture of argon and oxygen atmosphere under various sputtering powers in the range 0.38–1.50Wcm−2. The influence of sputtering power on the structural, electrical and optical properties was systematically studied. The films were polycrystalline in nature with cubic structure. The films formed at sputtering powers ≤0.76Wcm−2 exhibited mixed phase of Cu2O and CuO while those formed at 1.08Wcm−2 were single phase Cu2O. The single-phase Cu2O films formed at a sputtering power of 1.08Wcm−2 showed electrical resistivity of 46Ωcm, Hall mobility of 5.7cm2 V−1 s−1 and optical band gap of 2.04eV. [Copyright &y& Elsevier]

Abstract: This paper reports the results of an investigation on the performance of the Diffusive Gradient in Thin Films (DGT) Technique in speciation of metals in aqueous samples of municipal wastes and mine effluents. The DGT was assessed regarding its suitability for in situ determination of metal speciation in municipal wastes and aqueous mine effluents. As the thickness of the diffusive gel layer of the DGT was increased to 0.40, 0.80, and 1.60mm, a decrease in the amount of accumulated metal mass was observed for most of the metals studied in all the effluent samples. However, the results were different from one field-study site to another. Effect of kinetics also was observed in the amount of accumulated metal mass by the DGT. The computer speciation code, Windermere Humic Aqueous Model (WHAM VI), was used to predict the metal speciation of Cd, Cu, Ni, Pb, Co, and Zn, and WHAM predictions were compared with those of the experimentally determined metal speciation by the DGT technique (free and labile metal ions). This comparison showed good similarities between the theoretically predicted WHAM VI values and the experimentally measured values by DGT. The DGT technique was found to be simple and useful for investigating chemical speciation of trace metals in aqueous samples of municipal wastes and aqueous mine effluents. [Copyright &y& Elsevier]

Abstract: There has been a debate on the mechanism of resistive switching in Rose Bengal and other Xanthene class molecules. While some authors proposed that the switching was due to an oxide layer at the Rose Bengal/Aluminum interface, some inferred the switching as an extrinsic effect like filament formation. We show results from Rose Bengal and other Xanthene class molecules on doped Si. Conductance switching in such monolayers induced by Pt/Ir tip of a scanning tunneling microscope (STM) in a non-contact mode shows that resistive switching in these molecules, initially reported by us in 2003 (in thin films), is indeed a molecular phenomenon. [Copyright &y& Elsevier]

Abstract: Pentacene-based transistors produced by a novel neutral cluster beam deposition method were characterized, and the effects of the surface pretreatments were examined. Atomic force microscopy and X-ray diffraction showed that the cluster beams were quite efficient in growing high-quality, crystalline thin films on SiO2 substrates at room-temperature without any thermal post-treatment, and that an amphiphilic surfactant, octadecyltrichlorosilane (OTS), enhances the packing density and crystallinity significantly. The observed field-effect mobilities (μ eff) were among the best reported thus far: 0.47 and 1.25cm2/Vs for the OTS-untreated and -pretreated devices, respectively. The device performance was found to be consistent with the estimated trap density and activation energy, which were derived from the transport characteristics for the temperature dependence of μ eff in the range of 10−300K. [Copyright &y& Elsevier]

Abstract: CdSe x Te1− x thin films of different compositions have been deposited on cleaned glass substrates using the hot wall deposition technique under conditions very close to thermodynamical equilibrium with minimum loss of material. The electrical conductivity of the deposited films has been studied as a function of temperature. All the films showed a transition from phonon-assisted hopping conduction through the impurity band to grain-boundary-limited conduction in the conduction/valence band at temperature around 325K. The conductivity has been found to vary with composition; it varied from 0.0027 to 0.0198Ω−1 cm−1 when x changed from 0 to 1. The activation energies of the films of different compositions determined at 225 and 400K have been observed to lie in the range 0.0031–0.0098 and 0.0285–0.0750eV, respectively. The Hall-effect studies carried out on the deposited films revealed that the nature of conductivity (p or n-type) was dependent on film composition; films with composition x=0 and 0.15 have been found to be p-type and the ones with composition x=0.4, 0.6, 0.7, 0.85 and 1 have been observed to exhibit n-type conductivity. The carrier concentration has been determined and is of the order of 1017 cm−3. The majority of carrier mobilities of the films have been observed to vary from 0.032 to 0.183cm2 V−1 s−1 depending on film composition. The study of the mobility of the charge carriers with temperature in the range of 300–450K showed that the mobility increased with power of temperature indicating that the type of scattering mechanism in the studied temperature range is the ionized impurity scattering mechanism. [Copyright &y& Elsevier]

Abstract: We have investigated the optical and photovoltaic properties of hybrid organic solar cells based on the blend of poly-3-phenylhydrazone thiophene (PPHT):ZnO and PPHT:dye:ZnO. In this architecture, ZnO and PPHT were the electron acceptor and donor, respectively, and dye was used both as acceptor as well as sensitizer to enhance the photon absorption in visible region. These results showed that on incorporation of dye in PPHT: ZnO composite the light absorption, exciton separation and photocurrent under white light dramatically enhanced. The dependence of photovoltaic parameters on the weight fraction of ZnO in PPHT: ZnO was also investigated. It is found that the device with 45% of ZnO in both composites exhibits the best photovoltaic performance. The thermal annealing of PPHT: ZnO-based device gives rise to a significant increase in power conversion efficiency as evident from the measurements of incident photon to charge carrier efficiency (IPCE) spectra and current–voltage characteristics under illumination. The absorption band of PPHT: ZnO blend becomes stronger and the absorption peak ascribed to PPHT is shifted towards the longer wavelength region (red shift) upon thermal annealing. The effect of solvent used for thin-film fabrication was also studied. It is also observed that the fluorescence (FL) quenching and solar cell efficiency were found to be strongly dependent on the solvent used for spin coating. [Copyright &y& Elsevier]

Abstract: Optical properties of nanocrystalline Nd-modified lead–zirconate–titanate thin films were studied. Pulsed laser deposition was used for thin-film fabrication at room temperature. Thin films were deposited on single-crystal MgO (100) substrates and post-annealed between temperatures 400 °C–1000 °C. The crystal structure and thin film morphology were studied using x-ray diffraction technique and atomic force microscopy, respectively. The optical transmission spectra of the films were measured at UV–vis–IR wavelengths and the results were utilized to obtain the refraction index n, extinction coefficient k, and the value of the band gap E g. Thin films annealed at different temperatures had a different crystal structure and morphology. Film thickness and annealing temperature also had an effect on the crystal orientation of the films. Trigonal and tetragonal phases co-existed in analyzed films so that films with thickness of 150 nm had strong tetragonal orientation with increasing post-annealing temperature. Trigonal and tetragonal phase co-existence was present in films with thickness of 300 nm post-annealed at low temperatures. Optical absorption edge shifted to shorter wavelengths with decreasing film thickness and post-annealing temperature which led to increase in band gap energies. Atomic force microscopy studies showed a clear dependence of films root mean square roughness on post-annealing temperature and crystal structure. [Copyright &y& Elsevier]