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Titanium oxide thin film compounds were grown on p-type Si (100) and BK7 glass as substrate using reactive DC magnetron sputtering. The effect of temperature growth on structural, optical and morphological properties was investigated. By means of X-ray diffraction (XRD) the phase composition was characterized. UV–Vis-NIR spectroscopy was used for reflection and transmission measurements of deposited thin film layers. Atomic force microscopy was used to evaluate and compute the surface roughness changes for different temperatures growth. The XRD results show that the temperature growth effects on the phase formation and structure. Increasing the substrate growth temperature would result in change of film thickness due to different phase and structure formation. The calculated band gap from optical measurements of the thin films shows a decrease at higher substrate temperature growth.

TiO2 films have been deposited on BK7 substrates by DC cylindrical magnetron sputtering setup in ambient temperature. The samples were fabricated at various O2/Ar reactive gas mixtures. The effects of changing O2 amount in O2/Ar reactive gas mixture on structural, morphological and optical properties of films were studied. The thickness of films was measured by surface profile meter. Thickness of films decreases with increasing the O2 amount in gas mixture. XRD studies shows that the films are amorphous. Atomic Force Microscopy was used to evaluate and compare the surface roughness and morphologies. The optical properties (transmission and reflection) of the samples were measured by UV–Vis–NIR spectrophotometer. Results show that increasing the O2 amount in O2/Ar mixture changes the surface morphologies and optical properties of films. All films exhibit a transmittance higher than 65 % in the visible region. The band gap of films was calculated from the optical measurements. The band gap of TiO2 thin films increases from 3.471 to 3.526 for different O2/Ar amounts.

Ta-Al-N thin films were deposited by cylindrical DC magnetron sputtering on a stainless steel substrate under varying nitrogen flow ratios ( N2 with respect to N2 + Ar in the range of 1.5%-9%. The effect of the N2 content in the reactive gas mixture on crystalline structure, surface morphology, and mechanical properties of Ta-Al-N thin films was investigated. The amount of Al and Ta in deposited films was obtained by energy dispersive X-ray spectroscopy (EDX) analysis and films thickness was measured by surface step profilometer. X-ray diffraction analysis (XRD) revealed that the crystalline structure of the Ta-Al-N polycrystalline thin film is a mixture of TaAl, TaN, and AlN crystalline phases. Surface morphology, roughness, and grain size were investigated by atomic force microscopy (AFM). The nano hardness of Ta-Al-N thin films, measured by the nanoindentation method, was about 9GPa maximum for samples prepared under 3% N2 , and the friction coefficient, obtained by nanoscratch analysis, was approximately 0.2 for all Ta-Al-N thin films. Other results were found to be affected considerably by increasing the N2 amount.

The amorphous W/WN bi-layer with excellent thermal stability was successfully prepared by hot-filament chemical vapor deposition method on SiO2/Si substrate. It was found that the W/WN bi-layer is technological importance because of its low resistivity and good diffusion barrier properties between Cu and Si up to 700 °C for 30 min. The thermal stability was evaluated by X-ray diffractometer (XRD) and scanning electron microscope. The XRD results show that the Cu3Si phase was formed by Cu diffusion through W/WN barrier for the 800 °C annealed sample. The formation of the Cu–Si compounds denotes the failure of the W/WN diffusion barrier with rapid increase in sheet resistance of the film. The microstructure of the interface between W/WN and Cu reflects the stability and breakdown of the barriers. The failure of this amorphous barrier occurs with heat treatment when the deposited amorphous barrier material crystallizes. The major part of Cu diffusion in polycrystalline structure with disordered grain boundaries is controlled by grain boundaries. AFM results indicated a rapid increase in surface roughness at the diffusion barrier failure temperature. It was found that the grain size plays an important factor to control the thermally stability of the W/WN bi-layer.

In this paper the physical properties of silver oxide thin film have been prepared on BK7 substrate at room temperature by reactive DC magnetron sputtering technique using pure silver metal target by varying oxygen partial pressure during growth at reported. The reactive sputter gas was a mixture of Ar (99.999%) and N2 (99.999%) with the different ratio Ar and N2 by volume at the constant pressure of the growth chamber. The X-ray diffraction measurements showed that by increasing O2 volume during the Growth, change in crystalline structure will occur. The Atomic Force Microscope images shown by increasing O2 volume, the RMS roughness decreasing consistently. The thickness of the thin films decreases (from 353 to 230 nm) with increasing oxygen partial pressure in chamber. The reflectivity of thin films was investigated with a spectrophotometer system, and the surface reflectivity measurements indicate that by increasing O2 volume growth, the optical properties of the films changes.

A plano-convex aspheric lens is designed to collimate the emitted light of the fiber optics. In this paper even orders of general aspheres are used to describe the aspheric surfaces sag. To determine the aspheric coefficient, the even asphere polynomial are fitted on the computed sag data. The surface sag data is determined using genetic algorithm method. The surface sag was analyzed by the commercial optical software package ZEMAX. For typical fiber optics, the numerical aperture (NA) of 0.22 was assumed. With this specification, the expected output spot diagram of 20 mm and the maximum aperture of 25.4 mm have been obtained. A comparison between here presented lens and the similar type of conventional lens has been carried out; the proposed aspheric lens corrected the spherical aberration, which led to increase in the collimated distance.

The morphological parameter of a thin film surface can be characterized by power spectral density (PSD) functions which provide a better description to the topography than the root mean square roughness and imparts several useful information of the surface including fractal and superstructure contributions. In the present work PSD spectra computed from atomic force microscopy (AFM) data were used for studying the morphology of three different titanium nitride thin films obtained by dc magnetron sputtering system. The power values of PSD for the AFM data were determined by the fast Fourier transforms algorithms. We investigate the effect of substrate temperature and crystallite sizes on the roughness of thin films surface.

The amorphous tantalum oxide thin films were prepared by DC reactive magnetron cylindrical sputtering onto p-type silicon (100) substrate. We report the composition and optical properties of thin films under O2 amount variation. The sample’s reflectance was measured with a UV-Vis-NIR spectrophotometer (320–850 nm). The optical characterization of thin layers was analyzed by ellipsometry in spectral region for wavelength from 250 to 850 nm to obtain the refractive index and film’s thickness. The RMS roughness and grain size were investigated by atomic force microscope (AFM). Simulations to Rutherford backscattering spectroscopy (RBS) data revealed film’s stoichiometry. The reflectance, refractive index, thickness, RMS roughness and grain size were found to be affected by increasing oxygen amount. We calculated the porosity of grown layers using measured refractive index at the wavelength of 633 nm.

Direct Current Cylindrical Magnetron Sputtering Setup was used to deposit ZnO thin films on BK7 substrates. The effects of changing O2/Ar reactive gas mixtures on the structural and optical properties of films were studied. Crystallinity and structure of films were obtained by X-ray diffraction (XRD). Preferential crystalline growth orientation of ZnO films detected by XRD was always along the (002) orientation. The thickness of films was measured by surface profilometer which showed thickness increasing from 68.7 to 80.8 nm for 3–6% O2 amount respectively. The morphology and roughness of the films were investigated by Atomic Force Microscopy (AFM). As oxygen gas amount was increased, the roughness and the grain size were decreased and the deposition rate was increased. The optical transmittance of ZnO films are obviously affected by the changing of O2/Ar reactive gas mixtures. All films exhibit a transmittance higher than 70% in the visible region. The optical band gap of films was measured by Tauc’s method. The results show that by increasing the amount of O2 in reactive gas mixture, the optical band gap of deposited films increases.

In this work, we report the effect of growth temperature (room temperature, 150, 200 and 250°C) during the deposition of tantalum nitride thin films by a reactive planar DC magnetron sputtering system on the steel substrates, in a constant nitrogen partial pressure of 15% has been studied. The X-ray spectrum of deposited tantalum nitride films indicated an increasing in intensity of sharp peak of hexagonal TaN and was evidence of grain growth at higher temperatures. By increasing temperature the streaks’ directions, observed from AFM micrographs, were varied.

The TiN thin films were deposited on p-type silicon (100) substrates using reactive planar DC magnetron sputtering system. The target was 99.99% pure Ti. The reactive sputter gas was a mixture of Ar (99.999%) and N2 (99.999%) with the ratio Ar (97%) and N2 (3%) by volume. Structural characterization of the coating was done using X-ray diffraction (XRD). The surface roughness of the coating was determined using an Atomic Force Microscope (AFM). The reflectivity of thin films was investigated by a spectrophotometer system. The X-ray diffraction measurements showed that by increasing the substrate temperature during the growth, change in crystalline structure will occur. The crystallite size of the films determined by Scherrer’s equation, and the crystallite size measured by AFM also increased by increasing the substrate growth temperature. The surface reflectivity measurements indicate that by increasing the substrate growth temperature, the optical properties of the films changes. The change in optical properties and crystalline structure of the films indicate that substrate growth temperature plays an important role in structure and morphology of the grown layers.

Al–Cu–N films have been deposited on steel substrate by DC magnetron sputtering. These samples were annealed at 200, 400, 600 and 800 °C under vacuum condition. The effects of annealing temperature on structure, morphology and optical properties of Al–Cu–N films were investigated. By means of X-ray diffraction (XRD) the phase composition was characterized. Atomic Force Microscopy (AFM) was used to evaluate and compare the surface roughness before and after annealing. Also UV–Vis–NIR spectrophotometer was used to investigate the optical properties of the samples. The results show that with increasing in the annealing temperature the intensity of the peaks gradually increased and the full width at half maximum (FWHM) of the peaks gradually decreased and also increasing in the grain size and the amount of the samples roughness during the annealing process are observed. It demonstrates that desirable reflectance and roughness of Al–Cu–N films deposited by DC reactive magnetron sputtering can be obtained by controlling the annealing temperature.

This work presents the results of a low-energy nitrogen ion implantation of AISI 304 type stainless steel (SS) at a moderate temperature of about 500°C. The nitrogen ions are extracted from a Kauffman-type ion source at an energy of 30 keV, and ion current density of 100 μA cm−2. Nitrogen ion concentration of 6 × 1017, 8 × 1017 and 1018 ions cm−2, were selected for our study. The X-ray diffraction results show the formation of CrN polycrystalline phase after nitrogen bombardment and a change of crystallinity due to the change in nitrogen ion concentration. The secondary ion mass spectrometry (SIMS) results show the formation of CrN phases too. Corrosion test has shown that corrosion resistance is enhanced by increasing nitrogen ion concentration.

In this paper the characteristics of Tantalum nanoparticles produced by laser ablation method is investigated experimentally with a first harmonic of a Q-switched Nd:YAG laser of 1064 nm wavelengths at 6 ns pulse. Spherical nanoparticles of Ta and tantalum oxide have been produced successfully by using a Ta target in ethanol. The fluency of laser was 0.9 J/cm 2 . The samples were characterized by using transmission electron microscopy (TEM), photo luminescence (PL), X-ray diffraction (XRD) and absorption spectroscopy analyses. The size of produced nanoparticles is mainly in the range between 10–20 nm, structural and phase compositional of produced Ta nanoparticles.

The surface modifications of Mo massive samples (0.5 mm foils) made by nitrogen ion implantation are studied by SEM, XRD, AFM, and SIMS. Nitrogen ions in the energy range of 16–30 keV with a fluence of 1 × 10 18 N + cm −2 were implanted in molybdenum samples for 1600 s at different temperatures. XRD patterns clearly showed MoN (0 3 1) (hcp) very close to Mo (2 0 0) line. Crystallite sizes (coherently diffracting domains) obtained from MoN (0 3 1) line, showed an increase with substrate temperature. AFM images showed the formation of grains on Mo samples, which grew in size with temperature. Similar morphological changes to that has been observed for thin films by increasing substrate temperature (i.e., structure zone model (SZM)), is obtained. The density of implanted nitrogen ions and the depth of nitrogen ion implantation in Mo studied by SIMS showed a minimum for N + density as well as a minimum for penetration depth of N + ions in Mo at certain temperatures, which are both consistent with XRD results (i.e., I Mo (2 0 0) / I Mo (2 1 1) ) for Mo (bcc). Hence, showing a correlation between XRD and SIMS results. This phenomenon is explained on the basis of residual gas, substrate temperature, dissociation of water in the chamber and the ion energy.

Depth and distribution of implanted ions play an important role in electrical and mechanical properties of implanted surfaces. In this study nitrogen implantation at 30 keV with different doses in the range of 1 x 10 17 -1 x 10 18 ions/cm 2 on AISI 304 stainless steel samples has been performed. The experimental and theoretical depth profiles of nitrogen-implanted samples are investigated. Experimental depth profile using secondary ion mass spectrometry (SIMS) is compared with theoretical analysis (TRIM simulation). By considering the presence of N 2 + in the implanting ion beam and sputtering effects, the TRIM and SIMS results were modified to good agreement. The proper ratio of N 2 + /N + is evaluated by a curve fitting procedure.

The production of p–n junctions and polar transistors in silicon to small scale lengths may be possible by plasma and electron beam techniques using the sub-threshold change of n-silicon into p-silicon by electron beam and its reversion at higher electron beam intensities. As a first step, in this study, experimental observation of the effect of electron beam on optical properties of n-type silicon samples is described. Electron bombardment with the energy of 20 keV and different doses in the range of 10 16 to 10 19 electron/cm 2 has been carried out. Use was made of a new design of an electron beam gun as described in details, using a helium obstructed discharge of a concave cold cathode. Optical properties of irradiated samples were determined by a UV–vis–NIR spectrophotometer. The results show an increase in the longer wave length than the fundamental band gap absorption with increasing electron dose. # 2004 Elsevier B.V. All rights reserved. PACS: 61.72.Tt; 78.68.+m

Reliable fabrication of lateral interfaces between conducting and semiconducting 2D materials is considered a major technological advancement for the next generation of highly packed all-2D electronic circuitry. This study employs seed-free consecutive chemical vapor deposition processes to synthesize high-quality lateral MoS2 -graphene heterostructures and comprehensively investigated their electronic properties through a combination of various experimental techniques and theoretical modeling. These results show that the MoS2 -graphene devices exhibit an order of magnitude higher mobility and lower noise metrics compared to conventional MoS2 -metal devices as a result of energy band rearrangement and smaller Schottky barrier height at the contacts. These findings suggest that MoS2 -graphene in-plane heterostructures are promising materials for the scale-up of all-2D circuitry with superlative electrical performance.

TaN-Ag thin films were deposited on a 304 stainless steel substrate by cylindrical DC magnetron sputtering using different ratios of nitrogen to argon gas. The N2 percentages were 1.5%, 3%, 4.5%, 7.5%, 10.5% and 15% by volume. The influence of the N2/Ar ratio on the films morphology, structure and hardness was investigated using Atomic Force Microscopy (AFM), Grazing Incidence X-ray Diffraction (GIXRD), and the nanoindentation method. The amounts of Ta and Ag were determined using Energy Dispersive X-ray Spectroscopy (EDS). The thickness of the deposited films was measured by surface step profilometer. The RMS surface roughness increased for N2 percentages up to 7.5% and then decreased. Grazing results showed different TaN phases and Ag crystalline structures. The hardness of all films was much higher than the hardness of bulk silver or tantalum. The highest hardness value was obtained for 1.5% N2 . The EDS results indicated that the Ag/Ta ratio in the deposited films increases with increasing the N2 amount from 1.5% to 15%. The size of Ag islands on the surface was maximized at 7.5% N2 in the gas mixture. The thicknesses of films were in the range of 400-600 nm.

In this paper we present the fabrication of cadmium telluride (CdTe) nanostructures by means of RF magnetron sputtering followed by low-energy ion implantation and post-thermal treatment. We have thoroughly studied the structural, optical, and morphological properties of these nanostructures. The effects of nitrogen ion bombardment on the structural parameters of CdTe nanostructures such as crystal size, microstrain, and dislocation density have been examined. From x-ray diffractometer (XRD) analysis it could be deduced that N+ ion fluence and annealing treatment helps to form (3 0 0) orientation in the crystalline structure of cadmium-telluride films. Fluctuations in optical properties like the optical band gap and absorption coefficient as a function of N+ ion fluences have been observed. The annealing of the sample irradiated by a dose of 1018 ions cm−2 has led to great enhancement in the optical absorption over a wide range of wavelengths with a thickness of 250 nm. The enhanced absorption is significantly higher than the observed value in the original CdTe layer with a thickness of 3 μm. Surface properties such as structure, grain size and roughness are noticeably affected by varying the nitrogen fluences. It is speculated that nitrogen bombardment and post-annealing treatment results in a smaller optical band gap, which in turn leads to higher absorption. Nitrogen bombardment is found to be a promising method to increase efficiency of thin film solar cells.

High Vacuum thermal evaporation was used to grow germanium islands on the silicon substrate covered by silicon oxide. The Ge nano-islands were formed by thermal annealing at different temperatures from 500 °C to 700 °C. Formation of islands was studied by various analytical techniques. The thickness of Ge layer was determined by rutherford backscattering spectroscopy (RBS). Also, combined with channeling technique, the composition and probable contaminants during synthesis processes were investigated. To explore the islands size and shape, both atomic force microscopy (AFM) and field emission scanning electron microscopy (FESEM) were used. Then the topographical images of surfaces were studied by AFM. The outcome of experimental evaluations of growth mechanism has indicated that with increasing the annealing temperature up to 700 °C, Ge islands were appeared from a uniform layer. Moreover, the statistical assessments of surfaces have shown that the nano-island’s sizes can be varied from several hundred nanometers to 30 nm by growing the annealing temperature. The reduction of the size along with an increase of the number of nano-islands after each thermal treatment is a major factor to prohibit us from seeing their clear images in AFM. The possibility of running statistical estimation on islands, instead, is the powerful tool of extracting and probing the distribution and the shape of Ge island’s peak in AFM images.

A beam shaping technique that rearranges the beam for improving the beam symmetry and power density of a ten-bar high power diode laser stack is simulated considering a stripe mirror plate and a V-Stack mirror in the beam shaping system. In this technique, the beam of a high power diode laser stack is effectively coupled into a standard 550 μm core diameter and a NA=0.22 fiber. By this technique, compactness, higher efficiency, and lower cost production of the diode are possible.

An effective technique for coupling the output of diode laser bars into optical fiber is demonstrated. The beam shaping method is based on stripe mirrors. Coupling with overall efficiency of 88% into a 365 μm fiber core diameter and 0.15 numerical aperture is achieved and the brightness is up to 430 kW/cm 2 .

In the crystal of the title hydrated salt, C5H7N2+·C12H10O2P−·H2O, the cations, anions and water molecules connected by N—H...O and O—H...O hydrogen bonds into a layer along the bc plane; the phenyl rings protrude into the space between the layers. The dihedral angle between rings of anion is 86.1 (1)°.

The thermoelectric properties of a T-shaped graphene nanodevice (TGN) are investigated by means of the Landauer approach using the π-electron tight-binding model. The dependence of thermopower on the temperature is studied and the results are qualitatively in agreement with many features recently observed in thermoelectric measurements on graphene nanodevice which suggests the existence of a minimum when the EF is several kBT away from the Dirac point. Thermoconductance κ is proportional to transmission coefficient and thermal current has a linear dependence on the temperature. Further, both the electrical and thermal current of electrons in TGN are calculated. The results could be useful in designing efficient graphene-based thermoelectric devices.

Ion implantation has been used to modify the mechanical properties of a wide range of metals and alloys using plasma techniques for ion sources and plasma surface treatment [1]. In this study AISI 52100 steel disks, containing 1.5 wt% Cr as the major alloying element, were implanted with nitrogen and carbon dioxide ions at the energy of 90 KeV, with dose in the range 1 × 1018 to 1 × 1019 N2+ ions cm−2, and 3 × 1018 to 1 × 1019 for co2+ ions cm−2. Ion beam current densities and sample temperature, during implantation were 3–6 μA/cm2 and 170°C, respectively. Experiments show, hardness of sample, increases 30–49% using N2+ ions, and 5–17% using co2+ ions. In order to explain the results, formation of beta‐CrN and carbide pahses have been carried out using X‐ray diffraction technique.

Titanium aluminum nitride thin film by DC magnetron sputtering was deposited on Si substrate. The thickness variation of titanium aluminum nitride for different Nitrogen and Argon gas composition at different wavelength in the range of 200 to 2500 nm is investigated using reflection spectroscopy. The morphology of titanium aluminum nitride films is characterized using atomic force microscopy AFM. Experimental results show that increasing the nitrogen gas in the mixture makes the film thicker and less reflective.

In this article, we produce titanium aluminum nitride thin film by using one of the most popular methods of Advanced Materials Functional Coatings Synthesis, DC magnetron sputtering. We deposited this film on glass substrate. The bulk matter resistivity variation of titanium aluminum nitride for different Nitrogen and Argon gas composition for different thickness is investigated using two methods together reflection spectroscopy for calculating thickness and four point measurements for surface resistivity. The morphology of titanium aluminum nitride films is characterized using atomic force microscopy AFM. Experimental results show that increasing the gas portion with respect to Ar gas in the mixture of gases makes the film less conductive. Formation of titanium aluminum nitride crystal structures for different gas mixtures was investigated using X-ray Diffraction.

The molecular conformation of the title compound, C28H21ClN2, is stabilized by an intramolecular C—H...N hydrogen bond. It has many pharmacological properties, such as being an inhibitor of P38 MAP Kinase, and can play an important role in biochemical processes.