Magnetron Sputtering Deposition Technique Research Articles

Surface Characterization of PEKK Modified by stron-tium–hydroxyapatite coating as implant material Via the magnetron sputtering Deposition technique

Background: The best material for dental implants is polyetherketoneketone (PEKK). However, this substance is neither osteoinductive nor osteoconductive, preventing direct bone apposition. Modifying the PEKK with bioactive elements like strontium hydroxyapatite is one method to overcome this (Sr-HA). Due to the technique's capacity to provide better control over the coating's properties, RF magnetron sputtering has been found to be a particularly useful technique for deposition.
 Materials and methods : With specific sputtering conditions, the RF magnetron technique was employed to provide a homogeneous and thin coating on Polyetherketoneketone substrates.. the coatings were characterized by Contact angle, adhesion test, X-ray diffraction (XRD), atomic force microscope and Elemental Analysis with Energy Dispersive X-Ray (EDX)
 Results : indicated that strontium hydroxyapatite had successfully deposited onto the surface with significant improvement in the wettability value to provide a suitable environment for cell attachment, spreading, proliferation, and differentiation
 Conclusion: Coating PEKK with RF magnetron sputtering can provide homogeneous surfaces laying the groundwork for improving PEKK's potential bioactivity, such as surface wettability. Wetting qualities are critical in implantable materials and are used to predict future osseointegration success.

Deposition, microstructure and nanoindentation of multilayer Zr nitride and carbonitride nanostructured coatings

Nitrides, carbides, and carbonitrides of transition metal elements like Zr, W, Ti, etc. are generally employed to produce hard coatings. Zirconium-based hard coatings have shown useful applications in the areas of tribology, biomedicine and electrical due to their high thermal stability, hardness, biocompatibility, good erosion, wear, and corrosion resistance. In this study, we created homogeneous and tenacious nanostructured hard coatings based on Zr with good mechanical properties. The magnetron sputter deposition technique was utilized to coat stainless steel 316L substrates with multilayers of Zr/ZrN and ZrN/ZrCN with individual layer thicknesses of 250 and 500 nm for each coating composition. The deposition conditions were adjusted to create two different coating thicknesses of 2 and 3 µm. The thickness of the coating was confirmed using Calotest and the coatings’ morphology and elemental composition were determined utilizing the atomic force microscope and scanning electron microscope equipped with energy dispersive x-ray spectrometer. Coating thickness and adhesion were measured using cross-sectional samples and XRD was utilized to analyze the coatings structure. Nanoindenter was employed to determine the instrumental nanoindentation hardness and elastic modulus. The influence of coating thickness on tribological behavior was further investigated using the ratio of nanohardness-to-elastic modulus (H/E). No evidence of decohesion was observed at the substrate/coatings interface, and the grains of all the coatings were observed to show columnar growth which were homogeneous, compact and dense. The grains of the ZrN/ZrCN coatings were observed to be denser, finer and more compact compared to those of the Zr/ZrN coatings. Correspondingly, higher hardness, modulus and H/E values were exhibited by ZrN/ZrCN than Zr/ZrN coatings. This suggests that the ZrN/ZrCN coatings are capable of exhibiting better wear resistance and fracture toughness. The coatings developed in this investigation are anticipated to be suitable for applications in tribology due to their excellent hardness and H/E properties.

Structure, Characteristics and Corrosion Behaviour of Gold Nanocoating Thin Film for Biomedical Applications

Nanocoatings thin films are layers deposited to improve required properties and corrosion resistance as a major objective for materials that are used for various biomedical applications such as biosensors. In this study, Gold (Au) thin films with 50 nm and 100 nm have been synthesized on Ni-Cr-Mo alloys by magnetron sputtering deposition technique. X-Ray diffraction (XRD), Atomic Force Microscopy (AFM), and Energy-dispersive X-Ray spectroscopy /Scanning Electron Microscopy (EDS/SEM ) have been used to distinguish the surfaces morphology. The results showed that there is no defects or micro-cracks with a uniform and homogenous film. It has spherical nanoparticles diameter morphology with 200-400 nm shaped to fine aggregation. The roughness average (Ra) decreased from 3.91 nm for 50 nm films to 3.70 nm for 100nm films with FCC crystal structure (111) for gold thin films. In vivo, after 50 nm and 100 nm nanocoated thin film by gold, a significant improvement in the localized corrosion resistance has been obtained in artificial saliva corrosive media at 37 °C compared with the uncoated surface.

Development of titanium nitride thin film microheaters using laser micromachining

In this paper, we report the fabrication and characterization of titanium nitride (TiN) thin-film-based microheaters. TiN thin films have been optimized on Si and SiO2 substrates for their optimum electrical resistivities by controlling the process parameters, including argon:nitrogen (Ar:N2) ratio in reactive pulsed DC magnetron sputter (PDCMS) deposition technique. An optical emission spectroscope (OES) was used for monitoring the plasma characteristics at various nitrogen flow rates. The microstructural and surface properties of the TiN films have been investigated and correlated with the electrical properties. It has been observed that the amount of nitrogen flux in the TiN plasma plays an essential role in the microstructural, surface, and electrical properties of the TiN thin films. Micro-heaters have been fabricated with TiN thin films with low electrical resistivity using laser engraving techniques instead of conventional lithographic and micromachining techniques. The TiN microheater has shown excellent performance. A temperature of 406 °C has been achieved by applying an input power of 8 W. This work paves the path for developing scalable and economic TiN microheaters using laser micromachining techniques.

Characterization of PN junctions of doped Mott insulators

A heterojunction comprising a La1.9Sr0.1CuO4 thin film on a 0.5 wt. % Nb doped SrTiO3 single-crystal substrate was fabricated using magnetron sputtering deposition and ion milling etching techniques. Rectification has been observed in the current–voltage characteristics of the heterojunctions from 30 to 300 K. The temperature evolution of the ideality factor implies the important role of barrier inhomogeneity at the junction interface. A systematic study of capacitance as a function of frequency under different bias voltages at room temperature was also carried out. The capacitance can be explained by deep-level defects in the space charge region.

Recent Advances in Alkaline Exchange Membrane Water Electrolysis and Electrode Manufacturing.

Water electrolysis to obtain hydrogen in combination with intermittent renewable energy resources is an emerging sustainable alternative to fossil fuels. Among the available electrolyzer technologies, anion exchange membrane water electrolysis (AEMWE) has been paid much attention because of its advantageous behavior compared to other more traditional approaches such as solid oxide electrolyzer cells, and alkaline or proton exchange membrane water electrolyzers. Recently, very promising results have been obtained in the AEMWE technology. This review paper is focused on recent advances in membrane electrode assembly components, paying particular attention to the preparation methods for catalyst coated on gas diffusion layers, which has not been previously reported in the literature for this type of electrolyzers. The most successful methodologies utilized for the preparation of catalysts, including co-precipitation, electrodeposition, sol–gel, hydrothermal, chemical vapor deposition, atomic layer deposition, ion beam sputtering, and magnetron sputtering deposition techniques, have been detailed. Besides a description of these procedures, in this review, we also present a critical appraisal of the efficiency of the water electrolysis carried out with cells fitted with electrodes prepared with these procedures. Based on this analysis, a critical comparison of cell performance is carried out, and future prospects and expected developments of the AEMWE are discussed.

A combined molecular dynamics/Monte Carlo simulation of Cu thin film growth on TiN substrates: Illustration of growth mechanisms and comparison with experiments

Using a sequential molecular dynamics (MD)/time-stamped force-bias Monte Carlo (tfMC) algorithm to simulate the deposition of Cu species onto a TiN(001) substrate at 600 K, it is shown for the first time that at the very early stage of growth, BCC-Cu grows pseudomorphically on the TiN(001) substrate as a very thin continuous film with the BCC-Cu[001]//TiN[001] growth direction. By increasing the thickness of the Cu thin film, however, the film transforms through the Nishiyama-Wasserman mechanism from BCC into predominantly FCC-Cu with abundant nanotwins, which is the same type of structure obtained in the experiment conducted here via a dc magnetron sputter deposition technique to grow Cu on TiN(001) at 105 °C. In agreement with the experimental observations in the literature, the devised MD/tfMC is employed further to reveal that on the N-terminated TiN(111), Cu shows a very poor wettability, and FCC-Cu(111) grows vertically in the form of tall 3D islands. On Ti-terminated TiN(111) surface, however, FCC-Cu(111) initially grows in the form of 2D islands with high wettability. With additional Cu deposition, a triangular misfit dislocation network is generated at the Cu(111)//Ti-terminated TiN(111) interface with subsequent formation of a two-layer nanotwin with its twinning plane parallel to the surface substrate.

Broadband wide-angle multilayer absorber based on a broadband omnidirectional optical Tamm state.

Recently, broadband optical Tamm states (OTSs) in heterostructures composed of highly lossy metal layers and all-dielectric one-dimensional (1D) photonic crystals (PhCs) have been utilized to realize broadband absorption. However, as the incident angle increases, the broadband OTSs in such heterostructures shift towards shorter wavelengths along the PBGs in all-dielectric 1D PhCs, which strongly limits the bandwidths of wide-angle absorption. In this paper, we realize a broadband omnidirectional OTS in a heterostructure composed of a Cr layer and a 1D PhC containing layered hyperbolic metamaterials with an angle-insensitive photonic band gap. Assisted by the broadband omnidirectional OTS, broadband wide-angle absorption can be achieved. High absorptance (A > 0.85) can be remained when the wavelength ranges from 1612 nm to 2335 nm and the incident angle ranges from 0° to 70°. The bandwidth of wide-angle absorption (0°-70°) reaches 723 nm. The designed absorber is a lithography-free 1D structure, which can be easily fabricated under the current magnetron sputtering or electron-beam vacuum deposition technique. This broadband, wide-angle, and lithography-free absorber would possess potential applications in the design of photodetectors, solar thermophotovoltaic devices, gas analyzers, and cloaking devices.

Growth and structural characterization of Sb2Se3 solar cells with vertical Sb4Se6 ribbon alignment by RF magnetron sputtering

Sb2Se3, (ASe) thin-films were deposited as the absorber layers in photovoltaic solar cells using the radio frequency magnetron sputtering deposition technique. Starting from a binary target, high quality crystallization and good vertical alignment of Sb4Se6 ribbons were attained at growth temperatures below 300 °C, and use of an additional selenization process was unnecessary for compensating Se loss. By the structural characterization of films grown on different substrates, a strong dependence of the ribbon orientation on the substrate type was verified. This study clearly confirms that the ribbon alignment is the key factor for enhancing the performance of Sb2Se3 solar cells, in particular the short circuit current density (J sc). A photovoltaic efficiency of 0.24% and a J sc of 5 mA cm−2 were obtained by depositing ASe on Mo, in a CuInGaSe2-like solar cell structure (Al:ZnO/ZnO/CdS/ASe/Mo/Glass), while the J sc was boosted up to 27 mA cm−2 when the ASe solar cells were fabricated in superstrate configuration with an Au/ASe/CdS/FTO architecture, leading to an efficiency of 2.36%.

Deposition of TiN and TiAlN Thin Films on Stainless Steel Tubes by a Cylindrical Magnetron Sputtering Method

Abstract Titanium nitride (TiN) and titanium aluminum nitride (TiAlN) coatings are very hard materials that are mostly coated on cutting tools to increase the tool life. These coatings have also been successfully applied as a coating material for biomedical applications mainly due to their tribological properties, biocompatibility, and affordable price. In an attempt to develop transition metal nitride coatings on specimens of cylindrical geometry, TiN and TiAlN thin films were deposited successfully on stainless steel tubes using a direct-current cylindrical magnetron cosputtering method. Both types of coatings were uniform in nature and had good adherence to the substrate. TiN and TiAlN thin films were characterized systematically to determine their structure, surface morphology, chemical states, chemical structure, and electrochemical behavior using X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and potentiodynamic methods, respectively. The XRD patterns of the TiN and TiAlN coatings indicated (111) preferential orientation. Cross-sectional SEM images revealed a columnar growth of the coatings with an arrow-headed geometry. XPS characterization showed the presence of TiN, Titanium dioxide, titanium oxynitride, aluminum oxide, and aluminum nitride phases. Potentiodynamic polarization tests in 3.5 % sodium chloride solution revealed that the TiAlN coating exhibited superior corrosion resistance compared with the TiN coating. Furthermore, TiAlN coating showed 94 % of average absorption in ultraviolet-visible region using photospectrometry. The cylindrical magnetron sputter deposition technique enables development of uniform protective coatings on tubular geometries, which are frequently employed in solar thermal and nuclear applications.

GROWTH AND MAGNETIC PROPERTIES OF DC MAGNETRON SPUTTERED Co0.2Fe0.8 THIN FILM

We report the growth and characterization of the [Formula: see text][Formula: see text] thin film. The thin film was deposited on Si (100) substrate by using a direct-current magnetron sputtering deposition technique. The Grazing Incidence X-ray Diffraction (GIXRD) analysis suggests a bcc crystal structure with a lattice constant of 2.87[Formula: see text]. The X-ray reflectivity (XRR) data analysis shows the thickness of the [Formula: see text][Formula: see text] thin film is about 30 nm. The Energy Dispersive X-ray (EDAX) analysis shows the presence of 22.94% of Co and 77.06% of Fe in [Formula: see text][Formula: see text] thin film. The Magneto-Optic Kerr Effect (MOKE) technique was used to investigate the magnetic properties and results support that [Formula: see text][Formula: see text]thin film exhibits soft magnetic character. The analysis of the M–H loop suggests that the value of the coercive field decreases with the increase of angle with respect to the magnetic easy axis. The MOKE measurement suggests that [Formula: see text][Formula: see text] thin film alloy exhibits the least anisotropy with two-fold magnetic anisotropy. Magnetization reversibility was observed by using high-resolution Kerr microscopy. The domain images showed that reversibility occurs through nucleation and domain wall motion. Magnetic anisotropy dispersion was also observed which may be due to the misalignment of grains in the film due to which we got the least anisotropy. These properties of the prepared sample found potential application in the field of spintronics and magnetic sensors.

Effect of Peak Power in Deep Oscillation Magnetron Sputtering on Film Properties

In the last decade, new magnetron sputtering deposition techniques have been developed to produce highly ionized fluxes of sputtered material and, consequently, allow greater control over the energy and direction of the sputtered species. One of such techniques is deep oscillations magnetron sputtering (DOMS). The main objective of the paper is to understand if the new deposition mechanisms that the DOMS technology brings about, in comparison to DCMS, is always an advantage for the film deposition. For this purpose, four well-known deposition systems (Cr, Ta, CrN and TiSiN) were investigated. In each case, thin films were deposited by DOMS and DCMS in order to compare their microstructural, structural and mechanical properties. Taken as examples, the four study systems are understood that, in some cases, it is possible to achieve film properties never achieved through DCMS. However, in other cases, due to their particular characteristics (high voltages), the HiPIMS advantages are diminished when compared to DCMS. Possible solutions to overcome the observed problems are proposed.

Validation of TiAlN functional coatings through cryo-tribological characterization using a pin-on-disk experiment

The purpose of this study has been to investigate the effects of TiAlN functional coatings in cryo-tribological pin-on-disk experiments. Nowadays, the introduction of new machining technologies for chip removal, both at high speed and in cryogenic conditions, is posing new challenges and opening new horizons to research. As a matter of fact, that in this technology needs to focus on the choice of workpiece materials to be machining and tools coatings used. For the latter, the wear phenomenon has been studied employing pins-on-disk (made by nickel-based alloys) under a liquid nitrogen jet flows simulating cryogenic machining. The coatings used have been of two different types: the coating C1 is a ZrTiAlN quaternary, while the coating C2 is a TiAlN/ZrN. The films were deposited with processes developed by the ENEA Brindisi laboratory using a dual magnetron sputtering and HiPPMS physical deposition technique. The wear measures were acquired employing a full factorial design with two factors: i.e., the test conditions (DRY or CRYO) and the pin coatings (not coated NC, coating C1 or C2). The number of tests was 12 since 2 were the replications. Based on preliminary experimental results, it can be stated that there is a type of coating, i.e., TiAlN/ZrN, that allows for high processing speed, high material removal, and a considerable increase in tool life.

Concentration quenching of photoluminescence in optically transparent Lu2O3:Eu thin films deposited to be used as scintillators

Photoluminescent thin films of europium doped lutetium oxide (Lu2O3:Eu) -an established material for x-ray scintillators- have been grown on glass substrates employing radio-frequency magnetron sputtering deposition technique. Optically transparent, crystalline films were obtained by only controlling the deposition process parameters. Neither any pre-treatment on glass substrate nor any post-deposition treatment on the films was applied. To our knowledge, depositing transparent but crystalline films of Lu2O3:Eu on glass substrates in such a direct way is an achievement that is reported for the first time in the literature. Using separate sputtering targets for the matrix constituent (Lu2O3) and the dopant enabled us to control the doping level of europium atoms in the films. By varying the magnetron power applied to the Eu2O3 target, we produced a series of Lu2O3:Eu thin films with different Eu concentrations. Significant quenching of luminescence by concentration was observed in the films. Detailed chemical and microstructural analyses revealed that europium atoms segregated from the matrix at high concentrations, an important contributor to concentration quenching. Some remarks have been given on finding the europium concentration that will give best scintillator performance.

Generation of a square-shaped pulse in mode-locked fiber lasers with a microfiber-based few-layer Nb2C saturable absorber.

Niobium carbide (Nb2C), a novel two-dimensional MXene material, has attracted much attention due to its outstanding electronic and optical properties. In this work, a microfiber-based few-layer Nb2C saturable absorber (SA) is fabricated by the magnetron sputtering deposition technique. The reverse saturable absorption (RSA) response of few-layer Nb2C nanosheets is observed with I-scan measurements. The square-wave pulses (SWPs) are generated by using the as-prepared microfiber-based few-layer Nb2C SA in an erbium-doped fiber laser. The SWP width increases from 0.33 to 2.061 ns with the single pulse energy increases linearly up to 0.89 nJ while the amplitude remains as a constant. In addition, nonlinear polarization rotation mode-locking fiber lasers with different cavity lengths are constructed to explore the formation conditions of SWP. Our results indicate that the RSA effect of the few-layer Nb2C nanosheets plays a decisive role in the formation of the SWP.

One-step synthesis of spontaneously graphitized nanocarbon using cobalt-nanoparticles

Amorphous carbon (a-C) films containing metallic Cobalt nanoparticles (Co NPs) were deposited onto microgrids and SiO2/Si substrates by a magnetron sputter-deposition technique at room temperature (RT) using aC target with an attachment of a small Co platelet. Transmission electron microscopy (TEM) with a fast Fourier-transform (FFT) revealed the short-range ordering of the lattice corresponding to graphite (002) between Co NPs in the amorphous C matrix. The 2D peak and graphite (002) peak were clearly observed in Raman spectra and x-ray diffraction (XRD), respectively, for the Co–C films. X-ray photoelectron spectroscopy analyses were used to determine the metallic state of Co NPs and sp2 graphitization in the film. Thus, the Co NPs exhibited higher catalytic activity in spontaneous graphitization at low-temperature than Ni-NPs prepared under the same conditions. So, the metallic NPs were concluded to be promising as the catalyst for the ultra-low temperature graphitization in the solid-phase reaction.

Bipolar conductivity in amorphous Cu–Al–O thin films prepared by r.f. magnetron sputtering

Bipolar electronic behavior has been demonstrated in amorphous Cu–Al–O thin films prepared on soda-lime glass substrate via radio frequency (r.f.) magnetron sputtering deposition technique. The tunable majority charge carrier type is as a result of the intentional adjustment of the percentage chemical composition of the material. Signs of Hall coefficients from Hall effect measurement and slopes of Mott-Schottky plots obtained for the films indicate the majority charge carrier type of each films. Negative Hall coefficient and a positive Mott-Schottky slope were obtained for the Al-rich film showing its n-type nature. Positive Hall coefficient and negative Mott-Schottky slope were obtained for the Cu-rich film showing its p-type nature. X-Ray Photoelectron Spectroscopy (XPS) was used to explain the variation in charge carrier type as a result of the adjustments made to the percentage chemical composition of the film. The I–V curves obtaine from simple devices fabricated show that the homojunction formed from the two films exhibit rectifying and photovoltaic properties. The rectifying behavior was studied between a bias of −1 V to +1 V. In addition, a VOC of 0.33 V, a JSC of 8.00 mA/cm2, an FF of 0.30 and a PCE of 0.79% were obtained from the photovoltaic device fabricated.

Synthesis, microstructural characterization and nanoindentation of Zr, Zr-nitride and Zr-carbonitride coatings deposited using magnetron sputtering

IntroductionHard coatings are primarily based on carbides, nitrides and carbonitrides of transition metal elements such as W, Ti, Zr, etc. Zr-based hard coatings show good resistance to wear, erosion, and corrosion as well as exhibit high hardness, high temperature stability, and biocompatibility, making them suitable candidates for tribological, biomedical, and electrical applications. ObjectivesThe present study aims to synthesize uniform and adherent hard Zr-based coatings that demonstrate sound mechanical integrity. MethodsStainless steel (SS316) samples were coated with single layers of Zr, Zr-nitride, and Zr-carbonitride using magnetron sputter deposition technique. Deposition conditions were controlled to produce each coating with two different thickness i.e., 2 and 3 μm. Calotest was employed to confirm coatings thickness. Scanning electron microscope fitted with energy dispersive x-ray spectrometer was used to ascertain the morphology and elemental constitution of coatings. Cross-sectional samples were examined to ascertain coatings thickness and adhesion. X-ray diffractometer was employed for structural analysis. Instrumented nanoindentation hardness and elastic modulus were determined with nanoindenter. Ratio of nanohardness to elastic modulus was evaluated to observe the effect of coatings thickness on tribological behavior. ResultsThree coating compositions were produced namely hcp-Zr, fcc-ZrN and fcc-Zr2CN. The highest hardness and elastic modulus were shown by ZrN coatings while pure Zr coatings showed the lowest values. ConclusionAll coating compositions were found to be relatively uniform, continuous and adherent with no evidence of decohesion at the coating-substrate interface. Coatings produced in this study are thought to be suitable for tribological applications.

Investigations on electronic and optical properties of Ag:MoS2 co-sputtered thin films

MoS2 semiconductor is a promising candidate for photovoltaic applications. The effect of Ag incorporation on optical properties of MoS2 thin films was observed in this study. First principle calculations were performed before experimental investigations using well known Wien2k code for estimation of variation in parameters with incorporation of 12.5% Ag content in MoS2. Pure and Ag incorporated MoS2 thin films were fabricated using magnetron sputter deposition technique. Experimentally found optical parameters approximately follow the similar trend observed in simulation. A sharp increase of absorption in Ag incorporated MoS2 thin film makes it more suitable for photovoltaic applications.

Multi-tube tantalum membrane reactor for HIx processing section of IS thermochemical process

HIx processing section of Iodine-Sulphur (IS) thermochemical cycle dictates the overall efficiency of the cycle, which poses extremely corrosive HI–H2O–I2 environment, coupled with a very low equilibrium conversion (~22%) of HI to hydrogen at 450 °C. Here, we report the fabrication, characterization and operation of a 4-tube packed bed catalytic tantalum (Ta) membrane reactor (MR) for enhanced HI decomposition. Gamma coated clay-alumina tubes were used as supports for fabrication of Ta membranes. Clay-alumina base support was fabricated with 92% alumina (~8 μm particle size) and 8% clay (~10 μm particle size), sintered at a temperature of 1400 °C. An intermediate gamma alumina coating was provided with 4% polyvinyl butyral as binder for a 10% solid loading. Composite alumina tubes were coated with thin films of Ta metal of thickness <1 μm using DC magnetron sputter deposition technique. The 4-tube Ta MR assembly was designed and fabricated with integration of Pt-alumina catalyst for carrying out the HI decomposition studies, which offered >80% single-pass conversion of HI to hydrogen at 450 °C. The hydrogen throughput of the reactor was ~30 LPH at a 2 bar trans-membrane pressure, with >99.95% purity. This is the first time a muti-tube MR is reported for HIx processing section of IS process.