Physical Sputtering Research Articles

Effect of Grain Size and Micromorphology of Cu Foil on the Velocity of Flyer of Exploding Foil Detonator

In this paper, the effect of grain size and micromorphology of Cu foil on the velocity of the flyer of an exploding foil detonator was studied. A Cu foil with different grain sizes and micromorphologies was prepared by the physical vapor deposition sputtering method. The flyer velocity of the Cu foil was measured by the photon Doppler technique (PDT). The influence of the grain size and micromorphology of the Cu foil (which was the core transducer of the exploding foil detonator) on the flyer velocity and reacted morphology was discussed. The results show that the grain size and micromorphology of the Cu film can greatly affect the velocity and morphology of the flyer. The grain size of the Cu film is more uniform, and the stimulus response in the middle area of the bridge foil is more concentrated. In addition, the current density becomes more uniform, resulting in a better explosion performance. Consequently, the speed of the formed flyer becomes higher, leading to a smoother flyer surface, which is more conductive to energy conversion.

Metallization of Thermoplastic Polymers and Composites 3D Printed by Fused Filament Fabrication

Fused filament fabrication allows the direct manufacturing of customized and complex products although the layer-by-layer appearance of this process strongly affects the surface quality of the final parts. In recent years, an increasing number of post-processing treatments has been developed for the most used materials. Contrarily to other additive manufacturing technologies, metallization is not a common surface treatment for this process despite the increasing range of high-performing 3D printable materials. The objective of this work is to explore the use of physical vapor deposition sputtering for the chromium metallization of thermoplastic polymers and composites obtained by fused filament fabrication. The thermal and mechanical properties of five materials were firstly evaluated by means of differential scanning calorimetry and tensile tests. Meanwhile, a specific finishing torture test sample was designed and 3D printed to perform the metallization process and evaluate the finishing on different geometrical features. Furthermore, the roughness of the samples was measured before and after the metallization, and a cost analysis was performed to assess the cost-efficiency. To sum up, the metallization of five samples made with different materials was successfully achieved. Although some 3D printing defects worsened after the post-processing treatment, good homogeneity on the finest details was reached. These promising results may encourage further experimentations as well as the development of new applications, i.e., for the automotive and furniture fields.

Molecular dynamics simulation for reactive ion etching of Si and SiO2 by SF5+ ions

Silicon (Si)-based materials such as Si and silicon dioxide (SiO2) are commonly used as basic components of advanced semiconductor devices. For example, alternating stacks of poly-Si and SiO2 layers are used in three-dimensional (3D) NAND flash memory devices. Fabrication of high-aspect-ratio deep holes through such stacked materials by plasma etching may be achieved by highly energetic and chemically reactive ion injections to the surface. Etching by sulfur hexafluoride (SF6) plasmas can produce ions carrying multiple fluorine (F) atoms and therefore exhibit high etch rates for both Si and SiO2. In this study, reactive ion etching of Si and SiO2 materials by SF5+ ions was examined with the use of molecular dynamics (MD) simulation. For this purpose, a simplified interatomic potential functions model for sulfur (S) was developed that approximately represents molecular moieties or molecules SFn (n≤6) based on density-functional-theory (DFT) calculations. The etching yields of Si and SiO2 by SF5+ ions evaluated by MD simulations with these new potential functions were found to be in good agreement with those obtained from multibeam injection system experiments, which implies that the etching process is essentially due to sputtering enhanced by chemical reactions of F atoms with the surface materials. Analyses of the depth profiles of atomic concentrations of etched surfaces and desorbed species obtained from MD simulations also indicate that the presence of excess F atoms on the surface enhances the etching yield of Si and SiO2 significantly over corresponding physical sputtering.

Physical Sputtering of a Copper Anode of a Planar Magnetron by a Beam of Accelerated Argon Ions with an Energy of 1–10 keV

Physical Sputtering of a Copper Anode of a Planar Magnetron by a Beam of Accelerated Argon Ions with an Energy of 1–10 keV

Power deposition behavior of high-density transient hydrogen plasma on tungsten in Magnum-PSI

The lifetime of plasma-facing components (PFCs) will have a strong influence on the efficiency and viability of future fusion power plants. However, the PFCs suffer from thermal stresses and physical sputtering induced by edge-localized modes (ELMs). ELMs in future fusion devices are expected to occur with a high plasma density compared to current day devices such that coupling of recycling neutrals and plasma ions will be strong. Because of the scale hierarchy of future fusion devices compared to the present ones, the influence of this coupling is difficult to predict. Here, we investigate the ELM-like hydrogen plasma induced heat loads on tungsten in the linear device Magnum-PSI, producing ∼1 ms plasma pulses with electron densities up to 3.5 × 1021 m−3. A combination of time-resolved Thomson scattering and coherent Thomson scattering was used to acquire plasma parameters in front of the target. Moreover, a fast infrared camera coupled to finite element thermal analyses allowed to determine the deposited heat loads on the target. We found a significant inconsistency between the plasma power calculated with a conventional collisionless sheath model and the absorbed power by the target. Moreover, plasma stagnation upstream and plasma cooling downstream were observed during the pulses. The observations are explained based on ionization and elastic collisions between the recycling neutrals and plasma ions. The results highlight the impact of plasma-neutral interaction on the power deposition behavior of ELM-like hydrogen plasma on tungsten.

Evaluation of silicon carbide as a divertor armor material in DIII-D H-mode discharges

Silicon carbide (SiC) represents a promising but largely untested plasma-facing material (PFM) for next-step fusion devices. In this work, an analytic mixed-material erosion model is developed by calculating the physical (via SDTrimSP) and chemical (via empirical scalings) sputtering yield from SiC, Si, and C. The Si content in the near-surface SiC layer is predicted to increase during D plasma bombardment due to more efficient physical and chemical sputtering of C relative to Si. Silicon erosion from SiC thereby occurs primarily from sputtering of the enriched Si layer, rather than directly from the SiC itself. SiC coatings on ATJ graphite, manufactured via chemical vapor deposition, were exposed to repeated H-mode plasma discharges in the DIII-D tokamak to test this model. The qualitative trends from analytic modeling are reproduced by the experimental measurements, obtained via spectroscopic inference using the S/XB method. Quantitatively the model slightly under-predicts measured erosion rates, which is attributed to uncertainties in the ion impact angle distribution, as well as the effect of edge-localized modes. After exposure, minimal changes to the macroscopic or microscopic surface morphology of the SiC coatings were observed. Compositional analysis reveals Si enrichment of about 10%, in line with expectations from the erosion model. Extrapolating to a DEMO-type device, an order-of-magnitude decrease in impurity sourcing, and up to a factor of 2 decrease in impurity radiation, is expected with SiC walls, relative to graphite, if low C plasma impurity content can be achieved. These favorable erosion properties motivate further investigations of SiC as a low-Z, non-metallic PFM.

Effect of ion beam etching on surface/subsurface structural defect evolution in fused silica optics

Ion beam etching through physical sputtering can also improve the laser-induced damage threshold of fused silica optics without introducing precipitation products or toxic fluoride solution, which makes ion beam etching an attractive alternative method for post-treatment. Researches indicated that ion beam etching could partially remove surface scratches and reduce the surface roughness of fused silica optics. In this study, the effects of ion beam etching on surface/subsurface structural defect evolution of fused silica optics were investigated. The results showed that chemically inert ion beam etching completely removes plastic subsurface structural defects and partially removes surface structural defects. Because of the lack of a sacrificial layer, ion beam etching has much lower removal efficiency for surface structural defects, especially deep structural defects, than for subsurface structural defects.

Bonding of LiNbO3 and Si wafers at room temperature using Si nanolayers

We report the room temperature bonding of LiNbO3 and Si wafers based on the use of Si nanolayers. The proposed method employs physical sputtering, which simultaneously activates the surface of an etched Si wafer and forms a Si nanolayer on the surface of a LiNbO3 wafer. Following sputtering, both wafers are immediately brought into contact and the newly formed Si nanolayer acts as a nanoadhesive. The data presented herein demonstrate that this technique is more effective at directly bonding LiNbO3 and Si than the conventional surface-activated bonding method. Following activation, the bonded surface energy, which reflects the bond strength, was estimated to be approximately 2.2 J m−2. This result indicates that the bonding was strong enough to withstand the processes associated with the fabrication of microelectronics devices, including wafer thinning.

Impact of fine divertor geometrical features on the modelling of JET corner configurations

The modelling of JET corner configurations, in which the strike points are positioned deep in the corners of the divertor, is extremely challenging for edge plasma fluid modelling tools. To circumvent this technical limitation, a geometrical approximation has been proposed, consisting in considering an artificial minor modification of the geometry of the divertor targets plates. In this paper, we investigate how significantly this approximation impacts the output of transport simulations. Using the SOLEDGE2D-EIRENE transport code which has the unique capability to be able to cope with both the full and the approximated geometry, we have performed a density scan in H-mode for pulses in which the outer strike-point lies in the corner of the divertor. We report here how simulations in the artificial geometry differ from the ones in unaltered geometry. At the exception of low density cases, mid-plane profiles in the closed field lines region and the near scrape-off layer are little impacted. Further out however, in flux-surfaces that are concerned by the geometrical modification, we find that modifying the geometry leads to a strong overestimate of the plasma density. The density perturbation is not local and concerns the whole flux surfaces. Although the divertor geometry is modified only on the outer side, the largest impact is found at the inner divertor where densities are systematically overestimated by a factor that can exceed 10 in low density cases in the far Scrape-Off Layer (SOL) and temperature underestimated by 10 to 20 eV in most of the studied density range. The near SOL and strike point peak values are also impacted in the same direction with density changes by a factor of 2. As a consequence, the threshold to detachment of the inner divertor is found lower in the approximate geometry than in the unaltered one. Due to the large flux expansion between the outer and the inner target, the difference in plasma is especially sensitive at the top of the inner divertor baffle, which could have consequence on the evaluation of physical sputtering at that critical location. • Minor modification of the divertor geometry impacts the edge plasma equilibrium. • The impact is not local and can be larger on the opposite side of the divertor. • Care must be taken when modelling divertor geometry with approximate description. • Mean-field codes with up to the wall capability should be used in such cases.

Surface Engineered Iron Oxide Nanoparticles Generated by Inert Gas Condensation for Biomedical Applications.

Despite the lifesaving medical discoveries of the last century, there is still an urgent need to improve the curative rate and reduce mortality in many fatal diseases such as cancer. One of the main requirements is to find new ways to deliver therapeutics/drugs more efficiently and only to affected tissues/organs. An exciting new technology is nanomaterials which are being widely investigated as potential nanocarriers to achieve localized drug delivery that would improve therapy and reduce adverse drug side effects. Among all the nanocarriers, iron oxide nanoparticles (IONPs) are one of the most promising as, thanks to their paramagnetic/superparamagnetic properties, they can be easily modified with chemical and biological functions and can be visualized inside the body by magnetic resonance imaging (MRI), while delivering the targeted therapy. Therefore, iron oxide nanoparticles were produced here with a novel method and their properties for potential applications in both diagnostics and therapeutics were investigated. The novel method involves production of free standing IONPs by inert gas condensation via the Mantis NanoGen Trio physical vapor deposition system. The IONPs were first sputtered and deposited on plasma cleaned, polyethylene glycol (PEG) coated silicon wafers. Surface modification of the cleaned wafer with PEG enabled deposition of free-standing IONPs, as once produced, the soft-landed IONPs were suspended by dissolution of the PEG layer in water. Transmission electron microscopic (TEM) characterization revealed free standing, iron oxide nanoparticles with size < 20 nm within a polymer matrix. The nanoparticles were analyzed also by Atomic Force Microscope (AFM), Dynamic Light Scattering (DLS) and NanoSight Nanoparticle Tacking Analysis (NTA). Therefore, our work confirms that inert gas condensation by the Mantis NanoGen Trio physical vapor deposition sputtering at room temperature can be successfully used as a scalable, reproducible process to prepare free-standing IONPs. The PEG- IONPs produced in this work do not require further purification and thanks to their tunable narrow size distribution have potential to be a powerful tool for biomedical applications.

Modeling the vapor shielding of a liquid lithium divertor target using SOLPS 4.3 code

In this letter, we report the very first results of SOLPS4.3 simulations of a liquid lithium (Li) divertor, including vapor shielding effects. A peculiarity of Li as a target coating material is the strong dependence of the erosion rate on the target temperature. We have implemented a new erosion model in SOLPS, taking this dependence into account. Simulations of the T15-MD tokamak divertor with Li-coated divertor targets have been performed. Li erosion is determined by physical sputtering, evaporation, and thermal sputtering. The results of the simulations show that a shielding effect occurs, providing a reduction of the target heat flux to values below 8 MW m−2. At the same time, the upstream plasma dilution in the high-power regimes, where shielding is most efficient, is very strong, meaning that in practical terms, it may be difficult to rely on the shielding effect for heat flux control in the configuration considered.

Atomic layer deposition of hafnium and zirconium oxyfluoride thin films

Hafnium and zirconium oxyfluoride films may act as effective protective coatings during plasma processing. The low molar volume expansion/contraction ratios and the small estimated strain values versus fluorination/oxidation suggest that hafnium and zirconium oxyfluorides can serve as protective coatings in both fluorine and oxygen plasma environments. To demonstrate the procedures for depositing these films, hafnium and zirconium oxyfluorides with tunable stoichiometry were grown using atomic layer deposition (ALD) at 150 °C. Tetrakis(dimethylamido)hafnium and tetrakis(ethylmethylamido)zirconium were used as the metal precursors. H2O and HF were employed as the oxygen and fluorine precursors, respectively. MOxFy (M = Hf and Zr) films were grown using two deposition mechanisms: the nanolaminate method and the HF exchange method. In situ quartz crystal microbalance studies were employed to monitor the MOxFy growth. Both deposition methods observed a linear MOxFy growth at 150 °C. The nanolaminate method is defined by the sequential deposition of MOx ALD and MFy ALD layers. Compositional tunability was achieved by varying the ratio of the number of MOx ALD cycles to the number of MFy ALD cycles in the nanolaminate. The HF exchange method is based on the thermodynamically favorable fluorination reaction of MOx by HF. Variable oxygen-to-fluorine concentrations in these films were obtained either by changing the HF pressure or by varying the thickness of the underlying MOx ALD layers. Ex situ Rutherford backscattering spectroscopy measurements were utilized to determine the composition of the various MOxFy thin films. Both deposition techniques displayed a wide range of compositional tunability from HfO2 to HfF4 and ZrO2 to ZrF4. In addition, the physical sputtering rates of MOxFy films were estimated from the film removal rates during ex situ x-ray photoelectron spectroscopy depth profiling. The physical sputtering rates increased with F concentration in the MOxFy films.

Precise ion energy control with tailored waveform biasing for atomic scale processing

Anisotropic plasma-enhanced atomic layer etching (ALE) requires directional ions with a well-defined ion energy to remove materials in a highly selective and self-limiting fashion. In many plasma etching systems, the ion energy is controlled using radio-frequency (13.56 MHz) sinusoidal waveform biasing. However, this yields ions with a broad energy distribution, while also inducing electron heating mechanisms that can affect the ion flux. In this work, we report on precise ion energy control—independent of the ion flux—using low-frequency (LF: 100 kHz) tailored bias voltage waveforms in a commercial remote plasma reactor. A prototype LF bias generator has been used to apply tailored waveforms consisting of a positive voltage pulse and a negative linear voltage ramp. These waveforms yielded ions having narrow energy distributions (7 ± 1 eV full-width-at-half-maximum) measured on dielectric SiO2 substrates for ion energies up to 200 eV in collisionless Ar plasmas. The mono-energetic ions were used to etch SiO2 thin films by physical sputtering. In these sputter etch experiments, the ability to accurately control the ion energy in the &amp;lt;100 eV range is demonstrated to allow for a more precise determination of sputter thresholds, which serve as valuable input for the design of novel ALE chemistries. The feasibility of performing anisotropic plasma etching using LF tailored waveform biasing was established by etching a SiO2 layer on a 3D trench nanostructure. The potential merits of this technique for the field of atomic scale processing are discussed.

(Invited) Reactions on Metal Surface and Diketone Induced By Gas Cluster Ions during Atomic Layer Etching

Gas cluster ion beams (GCIB), which consists of several thousands of gaseous atoms or molecules, have been used as novel low-energy ion beams for surface processing and analysis. Since thousands of low-energy (several eV) atoms bombard a surface at the same time and the same position, the bombarded area experiences transient high-temperature and high-pressure conditions, which enhance sputtering of atoms or enhance surface reactions. In recent years, we have been investigating to apply GCIB as energetic ions for atomic layer etching. We have reported ALE of transition metals (Cu and Ni) with GCIB irradiations and diketone (acetylacetone and hexafluoroacetone). We separated each etching step as following; (1) adsorption of diketone molecules on metal oxide, (2) evacuation of residual vapor, (3) irradiation of oxygen GCIB to remove metal oxide. By using 5 keV oxygen GCIB (~ 2eV/molecules), thin layer of nickel oxide with adsorbed acetylacetone is removed. There is no physical sputtering at this energy region, which realizes self-limiting ALE process. From in-situ XPS study, Ni oxide with adsorbed diketone molecules can be removed by Ar-GCIB irradiation. It means that other oxidation method can be used to form metal oxide, and Ar-GCIB can be used for the removal steps. In this talk, we will report surface reactions between metals and diketone induced by gas cluster ion irradiations, and etching characteristics of various metals using GCIB irradiation and diketone.

A Catalyst Based on Silver-Zinc Bimetal for Electrochemical Reduction of CO2 to CO

Energy and environmental issues have become the most significant challenges for human beings in the 21st century [1]. Among these issues, the continuing use of fossil fuels has led to increase the concentration of carbon dioxide (CO2) in the atmosphere, which has caused global climate change [2]. However, the CO2 reduction reaction have challenges due to the high overpotential and kinetically sluggish multi-electron transfer process. To solve these disadvantages, various bimetallic-based catalytic materials have reported. Because it provides a great potential for catalytic activity owing to their synergetic effects [3]. In the present study, we prepared an AgZn bimetallic catalysts by physical vapor deposition (PVD), which provides an ideal model for the electrochemical reduction of CO2 to CO. Three samples with different thicknesses of 2 nm, 5 nm, and 10 nm Ag layers, deposited on polycrystalline Zn pellets (poly Zn), were used for the electroreduction of CO2.All electrochemical experiments were conducted in a three-electrode system employing a potentiostat. An H-type electrochemical cell separated by a slice of Nafion 211 membrane was used for the CO2 electrochemical reduction. The electrolyte (0.1 M KHCO3) was saturated with CO2 (pH 6.8). The produced gas was directly introduced into the gas sampling loop of a gas chromatograph, which was equipped with a flame ionization detector (FID) for CO analysis and a thermal conductivity detector (TCD) for H2 analysis.The morphologies of Ag sputtered on the poly Zn were determined by TEM. It is observed that a 2 nm thickness Ag film forms Ag clusters of nearly circular shapes, which is likely an isolated island. As the thickness of Ag increases, the surface area covered by Ag also increases. The 10 nm sample shows the surface almost fully covered by Ag. All the XRD peaks of the Zn-based catalysts are indexed to the hexagonal wurtzite structure of Zn. However, the diffraction pattern of the 2AZ catalyst matches well with that of the poly Zn pellets and does not match with the diffraction pattern of Ag. It is because the amount of silver is too small to be detected. However, for the 5AZ and 10AZ catalysts, the diffraction peaks of Ag and Zn are observed. XPS was performed to demostrate the synergetic effect. Interestingly, the binding energy of Ag 3d of the AgZn compared to that for poly Ag is shifted towards a lower binding energy. Synergetic effect of AgZn catalyst could be attributed to the electron transfer from Ag to Zn, because Ag has a lower work function than Zn.To confirm the performance of CO2 reduction, the electrochemical experiments were conducted in CO2 saturated 0.1 M KHCO3 (pH =6.8) solution using a homemade H-type cell with a three-electrode system. The total current density of the 2AZ catalyst (3.53 mA cm−2) at −1.0 V is 2.05, 1.17, 1.38, and 1.28-fold higher than the total current densities of the poly Zn (1.72 mA cm−2), poly Ag (3.02 mA cm−2), 5AZ (2.56 mA cm−2), and 10AZ (2.76 mA cm−2), respectively. The 2AZ catalyst has the maximum CO conversion FE of 84.2% at a potential of −1.0 V vs. RHE, which is approximately 2.3-fold higher than that of poly Zn (35.9%), 1.5-fold higher than that of poly Ag (55.3%). the 2AZ catalyst exhibited excellent activity and selectivity for CO2 reduction to CO, even better than poly Au.Conclusively, we prepared AgZn bimetallic catalysts using a physical vapor deposition sputtering system. The 2 nm Ag deposited Zn catalyst selectively catalyzed the electrochemical CO2 reduction to CO with the FE of 84.2% at −1.0 V. The XPS analysis demonstrates a red-shift of the binding energy in the Ag 3d spectra, which results from the charge transfer from Ag to Zn. This indicates that the AgZn bimetallic structure can improve the surface charge transfer for CO2 reduction. This study can provide a new direction for further study on the electrochemical reduction of CO2 to CO.[1] H.-T. Pao, C.-C. Chen, J. Clean. Prod. 206 (2019) 907–919.[2] D. D. Zhu, J. L. Liu, S. Z. Qiao, Adv. Mater. 28 (2016) 3423-3452.[3] J.-H. Kim, S.-W. Yun, K. Shim, S.-H. You, S.-M. Jung, H. Kweon, S. H. Joo, Y. H. Moon, Y.-T. Kim, ACS Appl. Energy Mater. 3 (2020) 1423–1428.

Implementing sustainability in laboratory activities: A case study on aluminum titanium nitride based thin film magnetron sputtering deposition onto commercial laminated steel

The goal of the study was to identify the environmental hotspots of an experimental research work at lab scale consisting in the physical vapor deposition magnetron sputtering of aluminum titanium nitride based thin coatings onto commercial laminated steel. The findings can provide useful insights for supporting the design of future experimental research campaigns, or instrumentation set-ups, with lower environmental impacts. Results highlighted that the main driver of impacts in the analyzed laboratory activities was the electricity used for instruments operations, in particular for the vacuum keeping. Thus, several optimization strategies were evaluated to reduce the overall electricity consumption, and to improve the environmental profile of experimental activities.

Вторичная эмиссия атомных частиц при бомбардировке тяжелых d-металлов ионами из азотной плазмы

The results of kinetic modeling by the Monte Carlo method of sputtering heavy d-metals of Ir, Os, and W group by nitrogen N+ ions with energy in the range of 0.5–2.5 keV are presented. The coefficients of physical ion sputtering, the average sputtered atom energies, the reflection coefficients of the bombarding ions in the form of neutral nitrogen atoms, and the depth of ion penetration into the target were calculated. The calculations were performed for one-, two- and three-element targets, the partial ion sputtering coefficients of these metals were determined, and the influence of the surface binding energy on the ion sputtering parameters of individual target elements was studied. The calculations were performed for an Al target to compare the ion sputtering parameters of heavy d-metals and light aluminum. Despite the strong difference between the surface binding energy for these metals, their sputtering coefficients are of the same order of magnitude due to the fact that nitrogen ions penetrate deeper into aluminum and the exit of the recoil atoms from the target is impeded. The reflected or backscattered neutralized nitrogen atoms represent the second type of atomic particles emitted from the target. The coefficients of reflection of the bombarding nitrogen particles from the heavy metals and aluminum are determined.

Hydrophobic and UV-resistant properties of environmentally friendly nano-ZnO-coated wood

Abstract The combinations of nano-ZnO with wood through simple and efficient physical methods to prepare environmentally friendly and versatile Nano-ZnO-coated Wood have important research and practical implications. In this paper, an environmentally friendly nano-ZnO-coated wood was prepared by physical magnetron sputtering using Pinus sylvestris L. var. mongholica Litv. The micro-characteristics, structure, wettability and colour change of the ZnO-coated wood were characterized and studied. For samples with a sputtering time of more than 3 min, the surface water contact angle exceeded 130° and had good hydrophobic properties. After a 168 h accelerated ultraviolet (UV) ageing test, the total colour difference (ΔE ∗) of the sample with a sputtering time of 75 min (200 °C) was 77% lower than that of the original wood. When the substrate was at 200 °C, the ZnO films deposited on the surface of the wood were evenly and densely arranged, forming almost a continuous film. It could be seen that the deposition of a nano-ZnO film on the surface of wood could significantly improve its hydrophobic properties and anti-UV photochromic properties.

Tungsten and Molybdenum Surfaces Exposed to Warm Deuterium Ion Plasma with Q-Nonextensive Distribution of Electrons

This work is concerned with the effect of non-Maxwellian electrons and obliqueness of magnetic field on magnetized plasma sheath characteristics, in which plasma interacts with tungsten (W) and molybdenum (Mo) surfaces via non-neutral plasma sheath using two fluids model. It is assumed that the singly charged positive ions are treated as warm fluid whereas the electrons obey q-nonextensive distribution. It is found that the q-nonextensive distributed electrons and the temperature of ions affect the entrance velocity of positive ions, which is a key parameter in the plasma sheath formation. Also, the nonextensive parameter q affects the distribution of ions and electrons in the sheath region and their distributions explicitly related with the electrostatic potential variation. The parallel and perpendicular components of ions velocity are affected by the obliqueness of magnetic field. As the nonextensivity of electrons increases, the gradient in electric potential increases towards the wall and hence the impact energy also increases. The obliqueness of magnetic field and impact energy of ions is a key factor that determines the physical sputtering rate, particle reflection and absorption from the target surface. Furthermore, the probability of particle reflection coefficient from the W-surface is higher than that of Mo-surface.

Quasi-Solid-State Electrochromic Cells with Energy Storage Properties Made with Inkjet Printing.

In common commercially available electrochromic glass panes, the active materials such as WO3 and NiOx films are typically deposited by either physical vapor or sputtering under vacuum. In the present studies, we report on the inkjet printing method to deposit both electrochromic and ion storage electrode layers under ambient conditions. An ion storage layer based on cerium modified TiO2 and electrochromic nanocrystalline WO3 were both prepared under the wet method and deposited as inks on conductive substrates. Both compounds possess porous morphology facilitating high ion diffusion during electrochemical processes. In particular, the ion storage layer was evaluated in terms of porosity, charge capacity and ion diffusion coefficient. A scaled up 90 cm2 electrochromic device with quasi-solid-state electrolyte was made with the aforementioned materials and evaluated in terms of optical modulation in the visible region, cyclic voltammetry and color efficiency. High contrast between 13.2% and 71.6% for tinted and bleached states measured at 550 nm was monitored under low bias at +2.5 volt and −0.3 volts respectively. Moreover, the calculated energy density equal to 1.95 × 10−3 mWh cm−2 and the high areal capacitance of 156.19 mF cm−2 of the device could combine the electrochromic behavior of the cell with energy storage capability so as to be a promising candidate for future applications into smart buildings.