Search

To overcome the limited oxidation resistance of the emerging class of transition metal borides, we suggest within this study novel quaternary diborides, Ti-TM-Si-B2 ± z (TM = Ta, Mo), achieving the compromise between excellent oxidation resistance and requirements of hard coatings. Single-phase AlB2-type structured Ti-TM-Si-B2 ± z films (3–5 µm) are sputter-deposited from TiB2/TMSi2 targets. The Ti-Ta-Si-B2 ± z coatings exhibit 36 GPa in hardness, while maintaining strongly retarded oxidation kinetics till 1000°C. Ti-Mo-Si-B2 ± z coatings preserve a hardness up to 27 GPa, although outperforming all their counterparts by featuring outstanding oxidation resistance with 440 nm oxide scale thickness after 1 h at 1200°C.

Detecting and identifying hydrogen gas leakage before a potential disaster is a critical safety concern. To address this issue, a low-cost and simple-design sensor is required with high response and fast sensing time, capable of detecting hydrogen gas even at low concentrations of 5–500 ppm. This study investigates the use of magnetron-sputtered SnO2 thin films with palladium as a catalytic layer to achieve better sensing output. The developed Pd-caped SnO2 thin film sensors showed increased sensitivity with increasing thickness, up to 246.1 nm at an operating temperature of 250 °C. The sensor with a thickness of 246.1 nm exhibited excellent selectivity for H2 gas, even in humid conditions, and was able to distinguish it from other gases such as CO, NH3, and NO2. The sensor demonstrated high response (99%) with a response/recovery time of 58 s/35 s for (5–500 ppm) hydrogen gas. The sensor showed linear response to H2 gas concentration variation (5–500 ppm) at 250 °C. The sensor was found to be mechanically stable even after 60 days in a high-humidity environment. The LOD of sensor was 151.6 ppb, making it a suitable candidate for applied sensing applications. The Pd-caped SnO2 thin film sensor with thickness of ~245 nm could potentially improve the safety of hydrogen gas handling.

Despite the widespread use of Ti6Al4V in orthopedics, the health concerns, innate bio-inert property and the pursuit of long-term implantation in the body limit its development. For these reasons, we intend to modify the chemical and physical properties of Ti6Al4V by the sputtered bioactive Ti–Ta–Nb films. All these elements exhibit great biocompatibility in human body and the Ti–Ta–Nb system can form more stable passive layer to prevent the corrosion. In this study, we evaluate the effectiveness of the surface modification for Ti–Ta–Nb system on Ti6Al4V and investigate the influence of bioactive element Ta content from 25, 33, to 50 at% by the bio-corrosion behavior, passivation, in-vitro biological analysis and in-vivo implantation. The results show the Ti–Ta–Nb system has higher corrosion resistance and better biological properties than Ti6Al4V. Furthermore, following the electrochemical tests and passive layer observation, with increasing Ta content in Ti–Ta–Nb system, the corrosion resistance increases. The in-vitro measurements demonstrate that the higher Ta content in this system would lead to favorable surface condition for cell viability, proliferation, differentiation and adhesion. As for the in-vivo response upon implantation, the Ta50 film demonstrates significantly greater osteointegration capability. In summary, the current results reveal that the Ti–Ta–Nb system could greatly promote the surface properties of Ti6Al4V, and Ta50 is demonstrated to be a more promising coating choice for orthopedic implants. The mechanisms of the influence on Ta via the corrosion resistance, passivation and biological performances have been extensively explored and discussed.

Transition metal oxide films (TMO) as passivating contacts with improved opto-electronic characteristics play an important role in improving the silicon solar cell device efficiency. In this report, the effect of sputtering power on the optical properties of MoOx and the quality of MoOx/n-Si interface for its application in a silicon solar cell as carrier selective contacts has been reported. The optical transmittance of the film greater than 80 % in the visible and near infrared region of the spectrum is observed, which further improved with sputtering power. The creation of oxygen ion vacancies, which acts as positively charged structural defects able to capture one or two electrons led to the decrease of optical band gap from 3.70 eV to 3.23 eV at higher power. The oxygen vacancies occupied by electrons acts as donor centers, which lies close to the valence band, were responsible for modulation in electrical properties. The electrical properties of MoOx/n-Si interface was analyzed using current-voltage (I-V) measurements for its application as selective contact. A significant change in the selectivity parameters, like barrier height, I0 and series resistance of MoOx, has been observed with dc power. These extracted parameters showed that the sputtering power has a great influence on the selectivity of the charge carriers.

In this study, the effects of different bias voltages (0, −100, −200 V) with an annealing temperature of 450 °C have been investigated on the structural and optical properties of zinc oxide (ZnO) thin film as a transparent conductive oxide (TCO) deposited by radio frequency (RF) magnetron sputtering method. The investigation on effects uniformity or the double effects of annealing on the layers prepared in different biases is the aim of this work. The prepared thin films were characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), UV–visible (Uv–Vis) spectroscopy, and four-point probe resistance measurement. The XRD patterns analysis confirmed the formation of crystalline c-axis (002) orientated hexagonal wurtzite structure of ZnO thin films. The transmittance spectra of ZnO thin films exhibited a transparency of nearly 90 % in the visible region. The direct optical band gap of ZnO thin films was calculated using Tauc’s plot, showing about 3.9 eV for the as-deposited (or before annealing) samples while post-annealing (or after annealing) reduced the band gap by 17 % to about 3.2 eV in all samples. Moreover, by applying a bias voltage of −100 V, not only the lowest sheet resistance was observed compared to that of the 0 V and −200 V, but also an increase in grain size and a reduction in surface roughness were observed. Moreover, annealing has shown that at a bias voltage of −100 V the structure and electro-optical properties of the thin films are improved, while the opposite occurs for −200 V.

The stellar evolution and chemical make-up of the Universe are determined by nuclear reactions occurring in a wide variety of stellar sites. Precise determinations of the cross sections of these reactions are crucial for the calculation of reaction rates and for the development of stellar evolution models. The Laboratory for Underground Nuclear Astrophysics (LUNA) collaboration has been at the forefront of the direct measurement of nuclear reactions at the low energies of astrophysical interest for the last 35 years. The many significant results achieved at LUNA have been made possible due to the low background conditions uniquely available thanks to its location deep underground at the Laboratori Nazionali del Gran Sasso. Another key aspect of these successes is due to the experience of the LUNA collaboration in the production and characterization of a variety of solid targets used in reaction measurements. In this review, the main production techniques of solid targets are described, as well as the common methods adopted for target degradation monitoring. We also present the results of recent measurements using these targets and the future plans of the LUNA collaboration for measurements using solid targets at the LUNA400 kV and the new Ion Beam Facility (IBF) 3.5 MV are also presented.

Magnetic nanoparticles have important applications in industrial textiles and can be used as filters for separating color and heavy metals from factory wastewater. One of the most important magnetic materials is iron oxide(Fe3O4). In this research, different sputtering systems were used for depositing iron oxide nanoparticles on the surface of the glass mat. Three-angle sputtering machine, DC sputtering, and DC magnetron sputtering were used for the deposition of Iron Oxide nanoparticles. Deposition of Iron oxide nanoparticles with three angel and DC sputter systems was not satisfactory, as the rate of sputtering is very low in these machines. Therefore, these two methods were discarded and the study was performed on the next method. The results related to DC magnetron sputtering were satisfactory. The glass mat was deposited by Iron Oxide with different exposure times of 2, 3, and 4 h. The thickness of the layer, structural shape, and existing elements on the surface, were investigated using different analytical instruments. The magnetic properties of deposited fabrics were studied with a vibrating-sample magnetometer (VSM) and photocatalytic properties were also discussed. [ABSTRACT FROM AUTHOR]

In this research, MgF2 and SiO2 thin films were prepared by the magnetron sputtering method on glass and ITO substrates. The crystal structure, morphology, and antireflection performance of the coatings were characterized using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and ultraviolet spectrophotometry (UV-vis) techniques, respectively. Furthermore, by utilizing both experimental characterization and optical film design tools, the best experimental parameters for every coating were identified. FESEM images confirmed proper growth of the layers on the substrates. EDAX analysis revealed that the manufactured layer consisted of Magnesium fluoride and silica. The study of optical properties demonstrated that the average transmission in the 400-1000 nanometer range exceeded 99%, indicating good agreement with theoretical results. Furthermore, the use of ITO as the substrate reduced the bandgap. [ABSTRACT FROM AUTHOR]

Ti implants used for the treatment of bones and teeth damaged by diseases and accidents must exhibit excellent bone-bonding ability. To develop novel Ti alloys with bone-bonding ability superior to that of conventional Ti alloys, we prepared alloy films of Ti and Ca, especially Ca is an essential element in the human body and the inorganic components of bones, via radio-frequency magnetron sputtering. Ti-Ca alloy films with various Ca concentrations were fabricated using different arrangements of Ti and Ca sources. The crystal and surface structures as well as in vitro bone-bonding ability of Ti-Ca alloy films with Ca concentrations of 6, 27, and 38 mass% were investigated. X-ray diffraction patterns revealed that the abovementioned Ti-Ca alloy films exhibit an amorphous structure. Results of X-ray photoelectron spectroscopy revealed that oxides and hydroxides of Ti and Ca were present on the surfaces of the Ti-Ca alloy films. In a simulated body fluid (SBF) immersion test, hydroxyapatite precipitated first on the surface of the Ti-27 mass%Ca alloy film, whereas the Ti-38 mass%Ca alloy film peeled off during immersion in the SBF solution. [ABSTRACT FROM AUTHOR]

Samples of coatings with a content of 18.98–74.29 wt % Cd are formed via the sputtering of vanadium and cadmium targets in low-pressure plasma and the sequential deposition of ultrafine particles. As a result of X-ray studies, it is found that below the concentration of 56.45 wt %, the films represent the α–V phase; with a higher cadmium content, the phases of solid solution and free cadmium coexist. On the basis of the obtained dependence of the lattice parameter of the α–V phase on the Cd content in the coating, a method for determining mass loss during annealing is proposed. The process of the diffusion of cadmium in the α–V phase and free cadmium in coatings is studied using the method of determining the diffusion coefficients during sublimation in vacuum. The diffusion coefficients of cadmium in solid solutions at 473–573 K vary within the range of (2–300) × 10–15 cm2/s, and diffusion coefficients of free cadmium in coatings vary within the range of ~(2–20) × 10–15 cm2/s. In both cases, the values of the activation energy 0.31–0.80 and 0.28–0.44 kJ/mol, respectively, indicate the vacancy mechanism of the process. On the basis of the weight loss of cadmium during annealing, the average sublimation rate is determined varying at 473–573 K in the range of (0.69–5.60) × 10–7 kg/(m2 s), which is acceptable in the technology for producing porous vanadium. [ABSTRACT FROM AUTHOR]

A developed vacuum-arc plasma-assisted method is applied to produce films of a high-entropy alloy from a multicomponent gas-metal plasma generated by the simultaneous independent evaporation of selected metal cathodes. New modes are revealed to allow the deposition of thin films of a high-entropy alloy, AlTiCrNbMo–N, with a nearly equiatom composition. The films are a multilayer nanocrystalline material with a body-centered cubic lattice, the parameter of which specifically depends on the concentration of elements in the alloy. The synchrotron-radiation technique demonstrates that films of the high-entropy alloy AlTiCrNbMo–N are stable when heated in air to temperatures not exceeding 620°C. [ABSTRACT FROM AUTHOR]

This study evaluated a new and unique method of sputtering corn grains with cold plasma to resist the growth of the fungus Aspergillus flavus and prevent or reduce its production of aflatoxin B1 (AFB1). Sputtering grains depended on the sputtering time, that is, 1, 2, and 3 min. In addition, coating the grains with silver powder and Arabic gum (Bulk), Arabic gum alone, and a control (without any addition) was done. All levels of sputtering had no impact on the germination of corn grain in the laboratory, which was 100%. The field experiments also showed 100% germination of sputtered corn seeds. There was no significant impact on plant growth, and the average weight of the plants was 613 g in controls, followed by 2 min sputtering treatment (571 g), then the 3 min treatment (569.9 g). However, plant height was highest for the 3-min sputtering treatment (150.5 cm), significantly different from all other treatments. After this treatment, the highest number of leaves/plant (42.6 leaves/plant) was also recorded with high chlorophyll content (111.61 spad.). The most encouraging result was that sputtering treatments at all three levels (1, 2, and 3 min) gave high protection to yellow corn grain against the growth and development of the toxic A. flavus compared to the controls. The average AFB1 concentration recorded was 4.1, 2.5, and 2.3 ppb in the sputtering treatments of 1, 2, and 3 min, respectively. On the contrary, the average concentration of AFB1 was 147.99 ppb in the controls. [ABSTRACT FROM AUTHOR]

The memory effect property, described as a reversible color persistence while the potential is withdrawn, is of particular importance to reaching zero-energy consumption electrochromic devices. Nevertheless, often observed in organic materials, it is poorly studied in oxides. In this study, electrochromic tungsten oxide thin films are elaborated at different working pressures by radiofrequency magnetron sputtering. The influence of the deposition pressure on the electrochemical properties of WO3 films as well as on their memory effect is investigated. Three kinds of WO3 films can be distinguished: with irreversible blue coloration, with reversible coloration presenting a high memory effect, and with reversible coloration with a low memory effect. The origin of these discrepancies is studied through the composition, the local atomic environment, and the morphology of the WO3 thin films. An increase of transmittance at 550 nm as low as 15.8% in 48 h in air and 5.2% in 24 h in the electrolyte is recorded. This study highlights a better understanding of the memory effect property of electrochromic oxides for low-consumption energy electrochromic devices, pointing out morphology as a key parameter. [ABSTRACT FROM AUTHOR]

Diamond-like carbon films with Ti dopant (Ti-DLC) are synthesized by reactive magnetron sputtering using a pure Ti metal target. This study determines the effect of methane flow ratios (Rm=CH4/(Ar + CH4), ranging from 4 to 12%) on the surface morphology, microstructure, mechanical properties, and cermet cutting tool insert features of Ti-DLC films. The GIXRD diffraction spectrum for Ti-DLC film depicts an amorphous structure. There are peaks for nano-crystalline TiC at 2θ values of 35.88°, 41.52°, and 60.14°, which respectively correspond to the (111), (200), and (220) planes of the face-centered cubic structure. The characteristic binding energy of C 1s, Ti 2p, and O 1s for Ti-DLC film is determined using a high-resolution XPS spectrum. Increasing Rm flow ratio (reducing Ti metal doping) increases the intensity of the Raman spectrum because there is an increased sp2-C (sp2/sp3 ratio) site fraction for DLC components. The experimental results show that the hardness of the DLC film increases from 11.07 to 14.76 GPa as the Rm flow ratio is increased from 4 to 12%. The adhesive strength of the Ti-DLC film coating is measured using a scratch test and shows that the film adheres well to the substrate. The Ti-DLC films are coated onto cutter inserts for the dry milling of an Inconel 718 workpiece, and the results show that all coated tools have a significantly longer tool life than uncoated tools. [ABSTRACT FROM AUTHOR]

The resistive switching (RS) behavior of multilayered ReRAM devices is typically influenced by two aspects: the intrinsic properties of the dielectric multilayer, and other extrinsic contributions. In this study, we deposited and investigated bi-layered memories incorporating ZnO and HfO 2 dielectrics. Different stacking sequences of the two oxides (ZnO/HfO 2 and HfO 2 /ZnO) were employed to explore the intrinsic contribution of the bilayer microstructure, while different top electrode configurations (Pt and Ti) were utilized to demonstrate the extrinsic impact. All devices exhibit characteristic bipolar RS behavior, showcasing their functionality. But interestingly, the device with a Pt top electrode displays digital RS behavior, while the one with a Ti top electrode exhibits analog RS behavior. The completely different switching types observed during the reset process of the ZnO-HfO 2 hybrid resistive memories are attributed to different interface charge migration process and structural characteristic. And as compared to the tailoring effect of stacking sequences (bilayer microstructure and oxide/oxide interface), the tailoring effect of top electrode configuration (electrode materials and oxide/electrode interface) is much stronger. Based on the latter, the switching ratio can be remarkably improved by at least two orders of magnitude, the reset voltage (energy consumption) can also be significantly reduced, and other discussed switching parameters can also show greater improvement. The comprehensive comparative analysis of intrinsic and extrinsic contributions provides valuable insights for exploring the RS mechanism and optimizing the design of bi-layered memory devices. [ABSTRACT FROM AUTHOR]

This paper discusses the optimization of an advanced process monitoring scheme with interdicting fault detection and classification (FDC) capabilities that improved the control over the process development of Tantalum Nitride thin film resistors (TaN TFR). Its implementation in a high-volume manufacturing environment resulted in a reduction of misprocessed wafers, shorter equipment downtime, higher throughput, enhanced process visibility, and yield improvement. Along with optimizing FDC capabilities, implementing a short loop sampling plan reduced the turnaround time for early electrical characterization by a factor of four; this allowed for timely inline adjustments within the fabrication process to tighten the statistical process control (SPC) over the distribution of the process control monitor (PCM) TaN resistor value and improve thin film uniformity. [ABSTRACT FROM AUTHOR]

Using a quaternary compound target, Cu(In,Ga)Se2 films are prepared using one‐step, selenization‐free direct current magneton sputtering (DcMS) and high power impulse magnetron sputtering (HiPIMS) methods. This study investigates how the sputtering power affects the composition, microstructure, morphology, and electrical characteristics of the films. Film crystallinity is found to be affected by the sputtering power utilized. The films deposited at 0.25 kW are amorphous, whereas those formed at 0.5–1 kW display a chalcopyrite structure with a (112)–preferred orientation. With increased sputtering power, the films' crystal quality improves, displaying a homogeneous and compact morphology free of peeling and cracking. Elemental measurement of the CIGS films reveals that, depending on the deposition method, the film composition deviates from that of the target. The electrical properties of the deposited films vary with increasing sputtering power. [ABSTRACT FROM AUTHOR]

Sputtering is a well-known physical vapor deposition method for the synthesis of coatings and thin films. When combined with other techniques, such as electrospinning, it becomes a straightforward yet effective method to prepare substrates that can render various morphological structures at the nano and micrometer scale. The resulting substrates possess high surface area, making them suitable for applications such as gas sensing and surface-enhanced Raman scattering (SERS). The present work reports the successful magnetron sputtering deposition of silver/zinc oxide (Ag@ZnO) onto cellulose acetate fibers. By adjusting the sputtering process parameters, we limited the deposition of ZnO and Ag to be under limited adatom mobility conditions. Secondary electron imaging revealed that the resulting ZnO morphology on the fibers presented a columnar grain morphology at the nanometer scale. The ZnO crystallites of the said grains possessed a wurtzite structure, as shown by Raman spectroscopy. Ag sputtering deposition onto the previously deposited ZnO-covered fibers, produced under limited adatom mobility and short deposition time, rendered nanoparticles of various shapes and sizes, as revealed by electron microscopy. Then, using benzenethiol (BZT) and rhodamine 6G (R6G) as the probe molecules, the Ag@ZnO/CA fibers were tested as SERS substrates. All the prepared composite materials showed good SERS response towards the BZT and R6G. In summary, the novel approach is a practical and straightforward route for preparing Ag/ZnO-based SERS substrates. [ABSTRACT FROM AUTHOR]

The effect of electron-beam irradiation (EBI) on MoS2-based photodetectors with various electrode structures was investigated to improve the electrical and photoelectrical properties. The MoS2 films were deposited at room temperature by RF magnetron sputtering and subsequently transformed into a two-dimensional layered structure by EBI treatment with the electron energy of 3 kV for 1 min. The electrical resistance and photoelectrical properties, such as photocurrent and photoresponsivity, of MoS2 films were examined with patterned Au/Ti electrodes as a top contact (TC) and a bottom contact structure. In addition, the interfacial effect of high-k dielectric materials of thin HfO2 film between MoS2 and the SiO2/Si substrate was investigated to enhance the photoelectrical property. The MoS2 photodetectors fabricated by the EBI before TC formation on HfO2 exhibited the highest photoresponsivity of 11.88 mA/W, which was an increase of 6500% from the EBI before TC structure on SiO2. We believe that this work contributes to the improvement of contact and interface properties of MoS2-based photodetectors readily and quickly compared with conventional high-temperature thermal treatment. [ABSTRACT FROM AUTHOR]

This paper presents a detailed study of a titanium–platinum thin film-based electrode preparation and its practical application in the electrooxidation of cyanides to help protect our environment. The novel electrochemical deposition process of Pt on nearly atomically smooth magnetron-sputtered Ti film has been used to prepare a highly effective glass|Ti|Pt composite electrode with high catalytic activity for the electrooxidation of cyanide ions. The composite electrode exhibits over a 90% electrical current efficiency in the cyanide electrooxidation process and can be used for the decontamination of highly concentrated KCN solutions (up to 0.1 M) without any chemical additives. A high current efficiency (70%) of Pt thin film deposition on a glass|Ti electrode was achieved using a potentiostatic double-pulse method. Fast Fourier transform electrochemical impedance spectroscopy revealed the oxidation kinetics for cyanide ions at the electrode. The glass|Ti electrode was prepared using the magnetron sputtering technique, which allows us to fabricate electrodes of any shape suitable for any electrochemical cell or electroplating bath. Meanwhile, electrochemical deposition of Pt on the glass|Ti electrode is an efficient and environmentally friendly method, since various salts of Pt and/or Pt-containing wastes can be used for electrodeposition instead of pure Pt, which is more expensive. [ABSTRACT FROM AUTHOR]

Sb2S3 is rapidly developed as light absorber material for solar cells due to its excellent photoelectric properties. However, the use of the organic hole transport layer of Spiro‐OMeTAD and gold (Au) in Sb2S3 solar cells imposes serious problems in stability and cost. In this work, low‐cost molybdenum (Mo) prepared by magnetron sputtering is demonstrated to serve as a back electrode in superstrate structured Sb2S3 solar cells for the first time. And a multifunctional layer of Se is inserted between Sb2S3/Mo interface by evaporation, which plays vital roles as: i) soft loading of high‐energy Mo particles with the help of cottonlike‐Se layer; ii) formation of surficial Sb2Se3 on Sb2S3 layer, and then reducing hole transportation barrier. To further alleviate the roll‐over effect, a pre‐selenide Mo target and consequentially form a MoSe2 is skillfully sputtered, which is expected to manipulate the band alignment and render an enhanced holes extraction. Impressively, the device with an optimized Mo electrode achieves an efficiency of 5.1%, which is one of the highest values among non‐noble metal electrode based Sb2S3 solar cells. This work sheds light on the potential development of low‐cost metal electrodes for superstrate Sb2S3 devices by carefully designing the back contact interface. [ABSTRACT FROM AUTHOR]

Comprehensive analyses of the atomic structure using advanced analytical transmission electron microscopy‐based methods combined with atom probe tomography confirm the presence of distinct glass–glass interfaces in a columnar Cu‐Zr nanoglass synthesized by magnetron sputtering. These analyses provide first‐time in‐depth characterization of sputtered film nanoglasses and indicate that glass–glass interfaces indeed present an amorphous phase with reduced mass density as compared to the neighboring amorphous regions. Moreover, dedicated analyses of the diffusion kinetics by time‐of‐flight secondary ion mass spectroscopy (ToF SIMS) prove significantly enhanced diffusivity, suggesting fast transport along the low density glass–glass interfaces. The present results further indicate that sputter deposition is a feasible technique for reliable production of nanoglasses and that some of the concepts proposed for this new class of glassy materials are applicable. [ABSTRACT FROM AUTHOR]

This article discusses the optoelectronic performance of Cu-graphene (Cu-G) film prepared by the sputtering of the Cu layer on graphene oxide (GO) before the thermal reduction process. Surface diffusion of Cu intervenes with the reduction mechanism of GO in a good way if the Cu is sufficiently thick after 120 s sputtering. The best crystal quality of Cu-G is indicated by the Raman spectra lowest ΓG = 69 cm–1 and highest ID/IG = 1.63. Originally, the thickness of Cu after 120 s sputtering is 12 nm while the thickness of spin-coated GO is 5.52 nm. After the thermal reduction, Cu-G is 2.1 nm with an additional 0.3 nm residual layer underneath. The optical transmittance of Cu-G film at λ = 550 nm is 89.3% and it has two surface plasmon resonances at 4.58 eV and 5.28 eV. The peaks of absorption at high energy UV possibly allow Cu-G to boost its electrical conductivity without costing its transmittance in visible light. In a dark condition, the measured sheet resistance is 54.07 Ω sq–1, Hall mobility of holes majority carriers is 37.48 cm2 V–1 s–1, and dc conductivity is 7.88 × 104 S cm–1. They can be translated into a relatively high figure-of-merit of transparent conductor equivalent to 59.9. The stable processing of Cu-G film makes it promising to integrate this process into the fabrication of relevant optoelectronic devices. [ABSTRACT FROM AUTHOR]

Nowadays, metal nanoparticles are one of the most important products of nanotechnology with wide applications in various industries, so researchers are looking to create alloy nanostructures with new structural and mechanical properties by combining these nanoparticles. Therefore, in this research, the surface morphology of nanometer silver–copper films doped with nitrogen impurity, prepared by direct current magnetic sputtering method at different time periods, was investigated with the help of atomic force microscope data. The statistical data obtained from the microscope demonstrated that the morphological properties of the films change with increasing sputtering time. By examining and analyzing the Δα parameter resulted from the f(α) diagram of the films, it was also found that the surface roughness of the films rises with the increase of the sputtering time, which could be due to the increase in the size of the particles owing to the growth method of the films. [ABSTRACT FROM AUTHOR]

In the literature, a magnetic "easy" axis perpendicular to the film plane at room temperature (i.e., perpendicular magnetic anisotropy - PMA) has been reported in Ni (nickel) layers with thicknesses below ≈15 nm. In this work, we observed room-temperature PMA in a-Si/Ni/a-Si (where a-Si denotes amorphous silicon) thin film structures with nickel layer thicker than 15 nm. Two layered structures were prepared by DC/RF triode sputtering: [a-Si/Ni/a-Si] sandwich structure and [a-Si/Ni/a-Si] 5 multilayer structure. The cross sectional STEM revealed uniform Ni layers with thicknesses of ≈17 nm in [a-Si/Ni/a-Si] 5 – multilayer and ≈28 nm in [a-Si/Ni/a-Si] – single-layer whereas amorphous Si layers were ≈15 nm and 170 nm thick, respectively. An amorphous Ni–Si interphase was also observed in the layered structures. The XRD showed patterns for fcc-Ni with dominant (111) orientation. No other crystalline phases were observed in the XRD patterns. To our knowledge, there are no literature reports of easy magnetization direction perpendicular to the film plane at room temperature for Ni layers with thickness of ≈28 nm as presented in this work. The origin of PMA in a-Si/Ni/a-Si films may be mainly attributed to the magnetoelastic anisotropy whereas the secondary source of PMA is believed to be the surface anisotropy and magnetocrystalline anisotropy of [111] columnar grains. Amorphous silicon layers (substrate) do not have a well-defined lattice structure like crystalline substrates. Therefore, they do not induce strains in the nickel layers through lattice mismatch as in the case of epitaxy. The strains can be caused by other factors such as diffusion-induced strain, thermal expansion mismatch or intrinsic stresses during the growth process. These results could be important for applications in memory devices, sensors, logic chips, magneto-optic, magneto-electronic and spintronic devices and in fundamental research, as well as first step toward preparation and understanding of the PMA in thick nickel layers. [ABSTRACT FROM AUTHOR]

In this study, the Fe–Co alloy is combined with cobalt ferrite (CoFe2O4) and nickel (Ni) to form Fe–Co/CoFe2O4 and Fe–Co/Ni clad sheets and their energy‐harvesting performance is evaluated. The Fe–Co/CoFe2O4 clad sheet exhibits an output voltage of 4.229 mV and an output power of 6.89 nW at a wind speed of 10 m s−1. The energy‐harvesting performance of both these clad sheets cannot be quantitatively compared owing to their different thicknesses, which result in varying volume and distance from the neutral plane. Nevertheless, the values of output voltage and power for Fe–Co/CoFe2O4 are higher than those for Fe–Co/Ni (2.107 mV and 0.294 nW). [ABSTRACT FROM AUTHOR]

This work analyzed and compared the optical and photoenergetic properties of low-emissivity coatings made from various dielectric materials deposited through magnetron sputtering following a systematic, comparable method. Different multilayer structures of silver-based low-emissivity coatings were studied using SnO2, ZnO, SiAlNx, and aluminum-doped zinc oxide (AZO, which is inherently a semiconductor, but it fulfils an optical dielectric function in this type of structure). The properties of the coatings were determined by spectrophotometric and sheet resistance measurements. Coatings with AZO as the dielectric layers obtain the best photoenergetic performance because silver growth is more efficient on AZO. We also studied the effect of ion bombardment on AZO and SiAlNx in an attempt to obtain a better low-emissivity coating, achieving better results when etching the dielectric layer with an ion gun. Regarding the structures' visible transmission, the oxides produced better transmission results. Based on the above, we concluded that AZO had the best optical and photoenergetic properties in our deposition system, observing, in the best-case scenario, improvements in emissivity from 0.083 with SnO2 to 0.058 with AZO and to 0.052 using an ion beam on AZO and improvements in visible transmission from 81.9% with SnO2 to 86.8% with AZO. [ABSTRACT FROM AUTHOR]

Today, monitoring and classification of hydrogen gas by metal oxide-based sensors are widely studying to improve their selectivity and stability. In present work, hydrogen sensing properties of magnetron sputtered deposited pure SnO2 thin films have been studied. The pure SnO2 thin film was deposited on glass substrate and as-deposited film was annealed at 450 °C for 6 hrs. The annealed SnO2 thin film has crystalline tetragonal structure, granular surface morphology and non-stoichiometry elemental composition of tin and oxygen vacancies. A higher gas sensing response is obtained for annealed SnO2 thin film as compare to as-deposited SnO2 thin film.A limit of detection (LOD) ~175 ppb is estimated for annealed SnO2 thin filmbased sensor. This sensor exhibits fast response and recovery time of 42 s/52 s for 50 and 500 ppm hydrogen gas, respectively. The sensor is found highly selective towards H2 gas in compare to different gases such as methane, carbon monoxide and nitrogen dioxide. [ABSTRACT FROM AUTHOR]

The corporation of rare earth metals (lanthanides series) with other metals gives good properties in different fields, such as protecting the metallic surface from corrosion risk. In this work, the investigation on adding gadolinium (Gd) and samarium (Sm) as rare metals to bio-inert titanium (Ti) as transition metal was done to protect stainless steel (SS 316L) as bio metallic implant which is used in biofield because of its excellent mechanical properties, low costs, biocompatibility, inertness, and mechanical properties, chemical stability, workability, and high corrosion resistance. The corporation was done through coating using direct current (DC) sputtering technique from the target of these metals mixture to measure some properties. The surface characterization by X-ray diffraction (XRD) gave many phases represented by different GdxNiy in addition to the Ni3Ti phase and Ni5Sm phase. The scanning electron microscopy and energy dispersive X-ray spectroscopy (SEM/EDS) results showed the distribution of coating metals as a dense thin film with a good ratio of coating metals; this dense film gave lower surface roughness as illustrated through Atomic force microscopy (AFM) examination from 25.20 nm for the uncoated sample to 15.12 nm for the coated sample with a reduction in the hardness from 187 HV for the uncoated sample to 119 HV for the coated sample as well as increasing contact angle test (wettability) from 90° for base stainless steel surface to 117.723° for coated surface, these results enhanced the compatibility with giving good resistance from corrosion test, with achieving protection efficiency equal to 99.02%.

TiO2 thin films obtained through Reactive Magnetron Sputtering (RMS) have been extensively studied in the last decades for several applications as photocatalyst and self-cleaning coats. However, reactive deposition through MS onto large area substrates can be troublesome due to inhomogeneous films thickness and poor adhesion between film and substrate. This paper investigates the deposition of TiO2 thin films on glass substrates through a two steps method, namely: 1- deposition of nanometer thickness Ti metallic films on glass substrate, through triode magnetron sputtering; 2- oxidation of the Ti film through thermal treatment in atmospheric air, to obtain stoichiometric TiO2 layers. The film oxidation was performed concomitantly to the glass thermal treatment carried out at 650 °C. Analysis through XPS depth profile indicates the formation of a chemically graded high entropy interlayer due to the interdiffusion of atoms from substrate to film and vice-versa, during the thermal treatment. The high entropy interface layer contributes to reduces the mismatch between the film and the substrate lattice, resulting in an improvement of film adhesion. The badgap analysis through Tauc method show two energy values, namely 3.2 eV and 2.9 eV, which can be attributed to TiO2-rutile layer and the high entropy zone at interface, composed by [Ca-Na-Si-Ti]Ox oxides. The wettability results show that the contact angle may be as low as 10° between a deionized water drop and the rutile-TiO2 surface, after activation with UV light irradiation, which is characteristic of super-hydrophilic surface.

At the focus of our investigation lies the precision fabrication of ultrathin platinum–gadolinium (PtGd) alloy films, with the aim to use these films for resistive hydrogen gas sensing. The imperative for sensitive and selective sensors to harness hydrogen’s potential as an alternative energy source drives our work. Applying rare earth materials, we enhance the capabilities of hydrogen gas sensing applications. Our study pioneers PtGd alloy thin films for hydrogen gas sensing, addressing a gap in existing literature. Here, we demonstrate the functional characteristics of 2 nm thick PtxGd100′x (x = 25, 50 and 75) alloy films, analyzing their hydrogen gas sensing properties, comprehensively examining the interplay between alloy composition, temperature fluctuation and hydrogen concentration. The effect of composition and structural properties on the sensing response were assessed using EDX and XPS. The films are tested at a temperature range between 25 °C and 150 °C with hydrogen gas concentrations ranging from 10 ppm to 5%. Hydrogen gas sensing mechanisms in PtGd alloy ultrathin films are explained by surface scattering. The unique combination of Pt and Gd offers promising characteristics for gas sensing applications, including high reactivity with hydrogen gas and tunable sensitivity based on the alloy composition.

Nanostructure formation on Co(110) surfaces was studied by using irradiation with cluster ion beams with oblique incidence and an energy of 250 eV/atom. In this work, the effect of the mass of the cluster projectiles on the process was analyzed. The launched clusters were formed by different types of charged atoms: He, Ne, Ar, Kr, and Xe. Due to the different collision processes, the formed surface patterns stand out more if the mass of the projectile atoms is greater, regardless of the angle of incidence of the clusters. Two processes control the morphological evolution of the surface during the bombardment phase: sputtering erosion and surface atomic redistribution. At grazing angles, the contribution of sputtering is greater during the process. In fact, heavier species give greater sputtering, and the redistribution factor becomes lower. The weight of redistribution is greater for intermediate angles above the critical angle (50° and 60°), since the displacement is greater for heavier species, and the redistribution factor takes substantially higher values. The experimental results point to a shift in the critical angle with the mass of the projectile atom. In the case of He, a very light ion, the results are marked by channeling and vertical displacements.

We have investigated lattice disordering of cupper oxide (Cu2O) and copper nitride (Cu3N) films induced by high- and low-energy ion impact, knowing that the effects of electronic excitation and elastic collision play roles by these ions, respectively. For high-energy ion impact, degradation of X-ray diffraction (XRD) intensity per ion fluence or lattice disordering cross-section (YXD) fits to the power-law: YXD = (BXDSe)NXD, with Se and BXD being the electronic stopping power and a constant. For Cu2O and Cu3N, NXD is obtained to be 2.42 and 1.75, and BXD is 0.223 and 0.54 (kev/nm)−1. It appears that for low-energy ion impact, YXD is nearly proportional to the nuclear stopping power (Sn). The efficiency of energy deposition, YXD/Se, as well as Ysp/Se, is compared with YXD/Sn, as well as Ysp/Sn. The efficiency ratio RXD = (YXD/Se)/(YXD/Sn) is evaluated to be ~0.1 and ~0.2 at Se = 15 keV/nm for Cu2O and Cu3N, meaning that the efficiency of electronic energy deposition is smaller than that of nuclear energy deposition. Rsp = (Ysp/Se)/(Ysp/Sn) is evaluated to be 0.46 for Cu2O and 0.7 for Cu3N at Se = 15 keV/nm.

The investigation of PVC surface characteristics involved the utilization of Monte Carlo simulation software, TRIM, to replicate the interaction between ion beams and the PVC surface. TRIM is a widely employed tool for examining surface structure. The analysis centered on the interactions between PVC surfaces and ions of hydrogen, helium, argon, and krypton. The ion beam irradiation was carried out at varying angles 0°, 15°, 30°, 45°, 60°, and 75° relative to the sample's surface normal, and it encompassed two distinct incident ion energies 1 keV and 1 MeV. The interplay between ions and the PVC surface can result in diverse processes, including sputtering, emission, and ionization, contingent upon the mass, incident energy, and angle of incidence of the ions. The calculation of stopping power (both nuclear and electronic) and the range of projectiles can also be determined using the same set of incident ions (H, He, Ar, and Kr) but within different energy spectrums (from 10 eV to 10 MeV). The stopping range is contingent on the incident energy and mass of each incident ion, a crucial factor in the process of implantation. This procedure finds applications in doping semiconductors or other materials, with potential uses in catalysis, gas sensing, and various chemical applications.

In the paper, the interaction of an accelerated C60 fullerene ion with silicon monocrystal surface has been studied using molecular dynamics simulation. The dependence of a resulting crater size and sputtering yield on the initial size of the target was obtained. We proposed that computational artifacts revealed in simulations appeared due to two main reasons: shock waves raised by impinging the C60 ion, came back through the periodic boundary increasing the temperature around the impact point; dissipation of the energy, brought to the surface by the fullerene molecule, between small amount of atoms in the small cell might also affect the simulated results. It was established that 11 × 11 nm is the least size of lateral crystal dimensions required for the valid results of the simulation of the 8 – 14 keV C60 ion impact.

The aim of this study was to evaluate the effect the thermal treatment on the structural and optical properties of zinc oxide (ZnO) films and zirconia nanoparticles/zinc oxide film composites (ZrO2-nps/ZnO-films: Comp). X-ray diffraction (XRD) measurements indicated that structural properties of the ZnO and the ZrO2-nps/ZnO-films: Comp were improved after the thermal treatment at 500 °C for 24 h in air atmosphere. Field emission scanning electron microscopy images showed that the thermal treatment promoted a smoother surface in the ZnO films, and in the ZrO2-nps/ZnO-films: Comp it induced partial agglomeration of the ZrO2-nps. High resolution transmission electron microscopy confirmed the presence and the crystalline nature of the ZrO2-nps. The band gap calculated by UV–Vis measurements exhibited an opposite trend. In ZnO films the band gap was reduced after thermal treatment whereas in ZrO2-nps/ZnO-films: Comp the band gap increased after this posttreatment. PL measurements supported the XRD results due to the wide PL emission band in the visible region, which was partially splitted after the thermal treatment. In fact, the PL visible band corresponding to the ZrO2-nps/ZnO-films: Comp was weakened after the thermal treatment. Fourier transformed infrared spectra of ZnO films without and with thermal treatment were very similar, exhibiting the characteristic Zn-O vibration and a carboxylate band. However, for ZrO2-nps/ZnO-films: Comp the carboxylate band was almost imperceptible.

This study investigates the sputtering properties of nano-columnar tungsten surfaces under 2 keV D2+ irradiation. It was conducted both by performing experiments in a highly sensitive quartz crystal microbalance setup as well as by numerical methods using two simulation codes called SPRAY and SDTrimSP-3D. A key question was whether the strong sputtering yield reduction observed in previous studies under 2 keV Ar+ irradiation is maintained when using a much lighter ion species like deuterium. For the latter, a substantially larger projected range in the material has to be expected. Therefore, a total confinement of the ion-solid interaction within the W nano-columns cannot be assumed a priori. However, both the experiments and the numerical simulations showed in good agreement that the geometrically induced sputtering yield reduction is still observed to the same extent despite the increased range of ions in the material. Thus, a potential application of such nano-columnar tungsten surfaces as plasma facing components in future nuclear fusion devices is not affected.