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Perpendicular magnetic anisotropy at transition metal/oxide interfaces plays a significant role in technological applications such as magnetic storage and spintronics. In this study, we investigate the effects of thermal annealing and Pt ultrathin interlayers on the magnetic anisotropy in Ni/NiO multilayers. Ni/NiO/Pt multilayers were fabricated via radiofrequency magnetron sputtering and natural oxidation. The static magnetic properties of the samples were studied using temperature-dependent SQUID magnetometry. We focus on a sample with a Nickel thickness of 6.7 nm in each multilayer period. This multilayer in Ni/NiO form showed the maximum enhancement of perpendicular magnetic anisotropy after mild thermal annealing in past work. In this work, we study the effects of ultrathin Pt interlayers on the magnetic properties of such a Ni/NiO multilayer before and after annealing. We have observed a further increase in perpendicular magnetic anisotropy, and we study the temperature-dependent magnetic properties of this system, which combines the favorable magnetic properties of Ni/Pt and Ni/NiO multilayers. [ABSTRACT FROM AUTHOR]

The incorporation of nitrogen during sputtering of silicon carbide (SiC) target facilitates formation of different technologically significant phases. The bonding nature in these phases serve as the means of enhancing the hardness and toughness of the overall film getting deposited as shown by nanoindentation tests. Raman spectra gives the carbonaceous point of view based on existing models. A heterogenous crystallization was evident from getting a G-peak doublet. The experimental evidence of theoretically predicted SiC2N2 and Si2CN4 phases as per the phase diagram were found and confirmed by EDAX studies. These stable phases provided enhanced mechanical properties of the coatings

Abstract The well‐developed high‐k technologies ease the integration complexity for HfO2‐based ferroelectric (FE) devices in the complementary metal‐oxide semiconductor processes. Sputtered HfxZr(1‐x)O2 (HZO) FEs have proven their thermal compatibility in back‐end‐of‐line (BEOL) integration processes with high remanent polarization (Pr) and a high cycling endurance. With the help of a tungsten oxide (WOx) bottom electrode, the sputtered HZO's FE properties are further advanced in this work. WOx is used to tune the oxygen content in the HZO film, providing an FE performance with a maximum 2Pr of 46 µC cm−2 and an endurance of 108 cycles. Based on this, sputtered HZO can compete with the atomic layer deposited HZO in the BEOL processes. In addition, WOx bottom electrodes enhance the FE capacitor behavior in a broad processing window, which relaxes the manufacturing restrictions.

Perpendicular magnetic anisotropy at transition metal/oxide interfaces plays a significant role in technological applications such as magnetic storage and spintronics. In this study, we investigate the effects of thermal annealing and Pt ultrathin interlayers on the magnetic anisotropy in Ni/NiO multilayers. Ni/NiO/Pt multilayers were fabricated via radiofrequency magnetron sputtering and natural oxidation. The static magnetic properties of the samples were studied using temperature-dependent SQUID magnetometry. We focus on a sample with a Nickel thickness of 6.7 nm in each multilayer period. This multilayer in Ni/NiO form showed the maximum enhancement of perpendicular magnetic anisotropy after mild thermal annealing in past work. In this work, we study the effects of ultrathin Pt interlayers on the magnetic properties of such a Ni/NiO multilayer before and after annealing. We have observed a further increase in perpendicular magnetic anisotropy, and we study the temperature-dependent magnetic properties of this system, which combines the favorable magnetic properties of Ni/Pt and Ni/NiO multilayers.

The erosion of the accelerating chamber walls is one of the main factors limiting the operational life of Hall effect thrusters (HETs), and it is mainly related to the sputtering of ceramic walls due to the impacting energetic ion particles. The erosion phenomenon is investigated by means of a numerical model that couples the plasma model HYPICFLU2, used for evaluating the local distributions of ion energies and incidence angles, and a sputtering model specific for the xenon–Borosil pair, which is the most used in HETs application. The sputtering yield model is based on the measurements by Ranjan et al. that are improved with a linear factor to include wall temperature effect, recently studied by Parida et al. The experimental eroded profiles of SPT100 walls are selected as benchmark. The results show that there is a decrease in erosion speed with time, in accordance with experimental measurements, but the model underestimates, by about 50–60%, the erosion at the channel exit, which suggests a stronger dependence of sputter yield on surface temperature. Thus, the need for new experimental measurements of sputtering in the range of impact energy, angle, and wall temperature, respectively, of 10–250 eV, 0–85°, 30–600 °C, arises.

Nanoindentation technique is generally used for measuring thinfilm mechanical properties such as hardness, modulus and stiffness. Nanoindentation of ceramic thinfilms of SiO2, Si3N4 and Al2O3 was deposited by radio-frequency (RF) magnetron sputtering on the stainless steel (SS304) substrates using a nanoindenter. Under varied sputtering conditions, the “as-deposited” film was amorphous. The as-deposited thin film had a thickness of 200 nm. The amorphous film was loaded/unloaded only once while operating in load control mode. Hardness and Young's modulus, two mechanical properties of the ceramic thinfilms, were also measured. When SiO2, Si3N4, and Al2O3 thinfilms are deposited onto stainless steel substrates using an RF magnetron sputtering, the roughness of the ceramic thinfilms is in the range of 8 to 12 nm. The nanoindentation results were compared, the hardness of the coatings is in the range of 6 to 9 GPa, and these ceramic coatings can be used as an adhesive layer for multilayer thin film coating.

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.

Metallic ceramic compounds, such as Ti3SiC2, are innovative materials that combine the properties of metals and ceramics. However, most methods used in synthesizing these materials employ high deposition temperatures. Hence, in this work, Ti3SiC2 thin film was prepared and deposited on a steel sample without heating or biasing using a magnetized sheet plasma source. The synthesis was carried out by sputtering titanium, silicon, and graphite targets with Ar plasma at different deposition times of 60, 90, and 120 minutes. Energy dispersive X-ray (EDX) and X-ray diffraction (XRD) scans of the samples confirmed the synthesis of the desired compound. Moreover, the wettability and surface energy properties of the coated substrate were calculated by contact angle measurements. Results showed that as the deposition time increased, the coated substrate became more hydrophobic. Indeed, these findings show that Ti3SiC2 deposited steel substrate, with its increased hydrophobicity, is a potential self-cleaning coating for industrial tools.

Niobium-based oxides have garnered increased attention in recent years for their remarkable enhancement of corrosion resistance, as well as biofunctional properties of various metallic materials, including 316L SS. However, the mechanical properties of these promising coatings have not been fully elucidated. This study investigated how much the environmental conditions (air, artificial saliva, and NaCl solution) impact the wear performance of 316L SS without and with Nb2O5 coatings deposited via the reactive sputtering technique. The results exhibited a notable decrease in friction coefficient (55% in air, 18% in artificial saliva, 10% in 0.9 wt% NaCl solution), wear area (46% in air, 36% in AS, 17.5% in 0.9 wt% NaCl solution), and wear rate (44.0% in air, 19.5% in AS, 12.0% in 0.9 wt% NaCl solution). Ultimately, the results obtained in the present study elucidate the synergistic mechanisms of corrosion and wear in 316L SS containing Nb2O5 coatings, highlighting its significant potential for applications in the biomedical sector.

Biospecimen imaging is essential across various fields. In particular, a considerable amount of research has focused on developing pretreatment techniques, ranging from freeze-drying to the use of highly conductive polymers, and on advancements in instrumentation, such as cryogenic electron microscopy. These specialized techniques and equipment have facilitated nanoscale and microscale bioimaging. However, user access to these environments remains limited. This study introduced a novel technique to achieve high conductivity in bioimaging by employing a magnetically controlled sputtering cathode to facilitate low-temperature deposition and low-electron bombardment. This approach allows for the convenient high-magnification observation of highly structured three-dimensional specimens, such as pill bugs and butterfly wings, and fragile specimens, such as single-cell protozoan parasites, using metal deposition only. Furthermore, it is easily accessible in the field of bioimaging because it does not require any pretreatment and enables surface analysis of biospecimens with an electron microscope using only a single pretreatment process. Protozoa, which are microorganisms, were successfully observed at high magnification without structural changes due to thermal denaturation. Furthermore, metallic film deposition and electrochemical signal measurements using these metallic films were achieved in pill bugs.

In this study, indium zinc oxide (IZO) thin films were deposited at different pressures by RF sputtering. The IZO thin films were examined using X-ray diffraction (XRD), SEM, and AFM instruments. The observed crystal orientations [(100), (101), and (008)] were obtained near 31°. The experimental results also reveal slight height variations on the surfaces of the IZO thin films, with average roughness (Ra) values of 2.431, 3.873, and 5.682 nm for sputtering pressures of 10, 20, and 30 mTorr, respectively. In addition, the IZO/Si sensor head and reference electrode were immersed in buffer solutions with various pH values (1, 3, 5, 7, 9, and 11) to measure pH sensitivity. A series of current-voltage (I-V) characteristic curves were obtained using a semiconductor parameter analysis instrument. The pH sensitivity of the IZO extended-gate field-effect transistor (EGFET) was calculated to be approximately 58.9, 56.4, and 52.3 mV/pH for 10, 20, and 30 mTorr sputtering pressures, respectively. The IZO pH-EGFET showed superior pH sensitivity and linear response and has great potential as a disposable pH sensor. [ABSTRACT FROM AUTHOR]

Li–Al–O thin films synthesized via the reactive magnetron co-sputtering have the potential to act as solid-state electrolytes in micro-batteries. In this paper, the constant RF power (155 W) and variable DC power (20–50 W) were applied to lithium (Li) and aluminum (Al) metal targets, respectively, in Ar/O 2 atmosphere to produce films with adequate ionic conductivity. The influence of DC sputtering power on the composition, microstructure, band gap energy, ionic conductivity, and dielectric loss of films were studied in detail. X-ray photoelectron spectroscopy (XPS) showed a shift of the Li 1s peak towards higher binding energy with increasing DC power. X-ray diffraction (XRD) spectra confirmed the amorphous state for all as-deposited films, while the post-annealed films at 950 °C contain the γ-LiAlO 2 phase. Field emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM) images revealed that the increasing DC power had a significant impact on the film morphology, enlarging grain size and increasing surface roughness. Energy dispersive X-ray (EDX) spectroscopy showed that increasing the DC power increased the Al content. The optical properties were examined by ultraviolet–visible (UV–vis) spectroscopy, which indicated that increasing the Al content led to a blue shift of the absorption edge and an increase in the band gap energy (5.40–5.68 eV). Increasing the DC power resulted in an improvement of room-temperature conductivity by two orders of magnitude (∼2.85 × 10−9 S cm−1) and a decrease in the activation energy from 0.54 eV to 0.32 eV. These results suggest that composition and microstructure significantly affect the ionic transport in co-sputtered Li–Al–O films. [ABSTRACT FROM AUTHOR]

Advancement in the understanding of fundamental aspects of Secondary Ion Mass Spectrometry (SIMS) has made this technique to be extremely powerful for quantitative materials analysis. The secondary ion emission process is a complex phenomenon involving various mechanisms to understand the mechanism. Among the existing mechanisms, the “electron-tunneling model” is the most accepted concept in the understanding of ionization probability for positive and negative ions. This model essentially concerns the survival probability of an ion emitted from the surface. As the intensity of secondary ions of a certain element depends strongly on the efficiency of ionization of a sputtered atom or molecule, the “local surface chemistry” plays a significant role in the secondary ion emission. This is purported as the “Matrix Effect” in SIMS, making the technique extremely challenging for quantification of materials in spite of the fact that it has the highest detection sensitivity (

This work reports on the properties of heterojunctions consisting of n-type Ga2O3 layers, deposited using ultrasonic spray pyrolysis at high temperature from water-based solution, combined with p-type NiO and Cu2O counterparts, deposited by radio frequency and reactive, direct-current magnetron sputtering, respectively. After a comprehensive investigation of the properties of the single layers, the fabricated junctions on indium tin oxide (ITO)-coated glass showed high rectification, with an open circuit voltage of 940 mV for Ga2O3/Cu2O and 220 mV for Ga2O3/NiO under simulated solar illumination. This demonstrates in praxis the favorable band alignment between the sprayed Ga2O3 and Cu2O, with small conduction band offset, and the large offsets anticipated for both energy bands in the case of Ga2O3/NiO. Large differences in the ideality factors between the two types of heterojunctions were observed, suggestive of distinctive properties of the heterointerface. Further, it is shown that the interface between the high-temperature-deposited Ga2O3 and the ITO contact does not impede electron transport, opening new possibilities for the design of solar cell and optoelectronic device architectures. [ABSTRACT FROM AUTHOR]

The possibility of ferroelectricity in orthorhombic V2O5 thin films was investigated. Films were deposited via either a chemical solution deposition (CSD) route or by RF magnetron sputtering. Highly (001) oriented V2O5 films were achieved with both deposition routes at temperatures as low as 300°C. No evidence for ferroelectricity was observed, even in films which had been doped to provide local nuclei for polarization reversal. Loss originated from mid-gap trap states stemming from oxygen vacancies that were observed with photoluminescence, supplemented by piezoresponse force microscopy measurements. These trap states may have helped mimic ferroelectricity in previous reports on V2O5. [ABSTRACT FROM AUTHOR]

Stent retrievers are medical devices that are designed to physically remove blood clots from within the blood vessels of the brain. This paper focuses on microfabricated nitinol (nickel–titanium alloy) stent retrievers, which feature micro-patterns on their surface to enhance the effectiveness of mechanical thrombectomy. A thick film of nitinol, which was 20 µm in thickness, was sputtered onto a substrate with a micro-patterned surface, using electroplated copper as the sacrificial layer. The nitinol film was released from the substrate and then thermally treated while folded into a cylindrical shape. In vitro experiments with pig blood clots demonstrated that the micro-patterns on the surface improved the efficacy of blood clot retrieval. [ABSTRACT FROM AUTHOR]

A model for the evolution of surface nanorelief under irradiation with gas cluster ions is proposed. The model is based on the consideration of individual cluster collisions with a surface. The amount of material sputtered from the collision area and the efficiency of its redeposition on other surface elements are determined. The model's performance is demonstrated through comparison with experimental data. The stages of smoothing the model harmonic relief are investigated. A new measure of surface smoothing efficiency is proposed. [ABSTRACT FROM AUTHOR]

An analysis of both experimental and theoretical data on the study of preferential sputtering of nickel-based and copper-platinum alloys under ion beam bombardment has been carried out. Contrary to existing models, it has been shown that the main factor determining the process of preferential sputtering is the ratio of the surface binding energies of the components. [ABSTRACT FROM AUTHOR]

Lowering the extent of unwanted reflection from the top surface of devices is essential for achieving higher efficiency. Reduction of reflection in the near-infrared range is experimentally demonstrated using dual-side coatings on different substrates with commonly available coating materials, with triple-layer coating on one side of the substrate and single-layer coating on the rear side. The extent of this reduction over a broad spectrum of more than 600 nm due to rear-side coating is evident from the analysis of four different substrates, with the effect being more pronounced for thinner substrates. The simulations suggest that the choice of the material for rear-side coating should be necessarily the one whose refractive index is less than that of the substrate, in order to reduce the reflection. A rear-side coating with silica of one quarter-wave thickness was capable of reducing reflection further in all the cases studied here, and the best antireflection was obtained for the substrate which has the largest refractive index variation with the rear-side coating material. [ABSTRACT FROM AUTHOR]

Radio frequency (RF) magnetron sputtering was used to sputter a thin layer of ITO:Ga with a purity of 97:3 at% on glass substrates. A layer of Zr with a purity of 99.99% was then deposited on the ITO:Ga layer by direct current magnetron sputtering. Finally, RF magnetron sputtering was used once again to deposit a thin ZnO layer with a purity of 99.99 at% on top of the Zr layer. The three-layered film structure was annealed in a vacuum at various temperatures in the range of 200–500 °C in order to prompt a rearrangement of the crystal structure and reduce the number of internal defects. The effects of the annealing temperature on the film thickness, electrical properties, optical properties, surface morphologies, and quality factors of the multilayered films were investigated. The trilayer film showed a minimum resistivity of 1.79 × 10−3 Ω-cm after annealing at a temperature of 500 °C and an average optical transmission of 88.14% after annealing at 300 °C. The optimal quality factor (1.44 × 10−3 Ω−1) was obtained for the film annealed at 500 °C. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

An excellent corrosion-resistant and good conductivity coating is desired for metal bipolar plate (BP) in proton exchange membrane fuel cell (PEMFC). In this view, a novel strategy to achieve this aim by introducing Al 2 O 3 into CrN film. Al 2 O 3 /CrN nanocomposite coatings are first prepared by co-sputtering. Subsequently, the microstructure, electrochemical corrosion resistance, interfacial contact resistances (ICR) and contact angle are systematically investigated. As a result, Al 2 O 3 /CrN nanocomposite coating shows a low corrosion current density of 0.084 μA/cm2 in room temperature and a low corrosion current density of 0.39 μA/cm2 at 70 °C, which highly meets the requirement of U.S. DOE 2025 targets. Besides, Al 2 O 3 /CrN nanocomposite coating displays a superior durability to pure Au film. It is revealed that Al 2 O 3 can hinder the growth of CrN columnar crystals and result in coating amorphization, which is the mechanism of Al 2 O 3 -promoted the CrN corrosion resistance. Furthermore, Al 2 O 3 /CrN coating also exhibits an excellent electrical conductivity, featuring a smaller ICR of 3.09 mΩ cm2. Inspired by these results, introducing Al 2 O 3 into CrN coatings can provide enlightening insights to design new non-noble-metal coatings for metal BP in future PEMFC manufacturing. Al 2 O 3 can hinder CrN columnar crystals growth and results in a high-performance Al 2 O 3 /CrN nanocomposite coating for metal bipolar plates in PEMFC. [Display omitted] • Al 2 O 3 /CrN coatings are first prepared to protect metal bipolar plates in PEMFCs. • Al 2 O 3 /CrN coated Ti plates shows a low corrosion current density of 0.084 μA/cm2. • The ICR value of Al 2 O 3 /CrN coated Ti plates is 3.09 mΩ cm2 under 150 N/cm2. • Al 2 O 3 /CrN coating shows a more excellent durability than pure Au film. • Al 2 O 3 incorporation can hinder the columnar crystals growth of CrN. [ABSTRACT FROM AUTHOR]

BACKGROUND: Infections related to joint prosthesis are still a major concern for orthopedic surgeons. Hydroxyapatite (HA) is a useful biocompatible material because of its good osteocompatibility. Antibacterial HA coatings have been fabricated with addition of antibacterial agents such as Ag to HA using the plasma spraying method. However, the plasma-sprayed HA coating suffers from fractures at large thicknesses. The sputter-coated HA thin film has a high density, and has been applied clinically for dental implants. However, there are no extensive studies on Ag-containing HA thin films. OBJECTIVE: The aim of this study was to prepare an Ag-containing HA thin film by sputtering, and evaluate its antibacterial effect and cytotoxicity. METHODS: The Ag-containing HA thin films were prepared by radio-frequency magnetron sputtering. The films were characterized using X-ray photoelectron spectroscopy, X-ray diffractometry, and scanning electron microscopy (SEM). The antibacterial activities and cytotoxicities of the films were also evaluated. RESULTS: The Ag/Ca molar ratio of the films increased with the Ag ratio in the target. The SEM observation of the hydrothermally treated films showed surfaces covered with globular particles. All Ag-containing HA films exhibited an antibacterial effect against E. Coli. The number of cells of the films decreased with the Ag ratio. The films subjected to the hydrothermal treatment exhibited a higher number of cells than the as-sputtered films. CONCLUSION: The Ag-containing HA thin film was effective in terms of antibacterial effect, and had a low cytotoxicity in the proliferation of osteoblast cells at a low Ag ratio in the target. [ABSTRACT FROM AUTHOR]

Sputter deposition of thermochromic VO2 thin films for smart window applications has been faced with several challenges including the need for high deposition temperature, extremely precise and narrow range of oxygen/argon flow ratio and target poisoning during sputtering. Deposition of VO2 at room temperature without oxygen followed by post-deposition annealing has been cited as one of the potential mitigations to the challenge. In this study, the effects of post-deposition annealing conditions on the structural, electrical and optical properties of VO2 thin films are reported. The films were prepared on soda lime glass substrates using DC magnetron sputtering of metallic vanadium target in argon atmosphere, at room temperature without oxygen followed by post-deposition annealing. The working pressure and argon flow rate were 5.2 - 5.6 x 10-3 mbar and 76 ml/min, respectively. Thereafter, the films were annealed in a low vacuum environment at different temperatures and times. The XRD results confirmed that all films annealed at different temperatures and times were monoclinic VO2 except for films annealed at a temperature of 300 oC. The results indicate that 400 oC and 20 minutes are the optimum annealing temperature and time, respectively, for fabrication of highquality VO2 films with improved stoichiometry and crystallinity. The films had resistivity change between the semiconducting and metallic phases of one order of magnitude and the transition temperature between ~ 58 oC and 63 oC. The highest peak transmittance and best optical switching of the annealed VO2 films was 53% and 18%, respectively, at a wavelength of 2500 nm for film thickness of 44 nm. The results suggest that room temperature deposition without oxygen followed by post-deposition annealing in a low vacuum environment may be adequate for the fabrication of switching VO2 thin films. [ABSTRACT FROM AUTHOR]

The phenomenon of hot carriers, which are generated through the nonradiative decay of surface plasmons in ultrathin metallic films, offers an intriguing opportunity for subbandgap photodetection even at room temperature. These hot carriers possess sufficient energy to inject into the conduction band of a semiconductor material. The groundbreaking use of iridium (Ir) ultrathin film as an ultraviolet (UV) plasmonic material on silicon (Si) for high‐performance photodetectors (PHDs) has been successfully demonstrated. Elevating the thickness of the sputtered Ir film to 4 nm yields a notable surge in photocurrent, registering an impressive 600 μA under 365 nm UV illumination with electron mobility of 1.37E3 cm2 V−1 s. This PHD exhibits excellent OFF‐ON photoresponses at various applied voltages ranging from 0 to 5 V, maintaining a stable photocurrent. Under UV illumination, it displays exceptional performance, achieving a high detectivity of 1.25E14 Jones and a responsivity of 1.28 A W−1. These outstanding results underscore the significant advantages of increasing the thickness of the Ir film in PHDs, leading to improvements in conductivity, detectivity, external quantum efficiency, responsivity, as well as superior sensitivity for light detection. [ABSTRACT FROM AUTHOR]

Ion irradiation can cause burrowing of nanoparticles in substrates, strongly depending on the material properties and irradiation parameters. In this study, it is demonstrated that the sinking process can be accomplished with ion irradiation of cube‐shaped Ag nanoparticles on top of silicon; how ion channeling affects the sinking rate; and underline the importance of the amorphous state of the substrate upon ion irradiation. Based on these experimental findings, the sinking process is described as being driven by capillary forces enabled by ion‐induced plastic flow of the substrate. [ABSTRACT FROM AUTHOR]

The use of electrochemical-metallization-based volatile threshold switching selectors in cross-point arrays has been widely explored owing to their high on–off ratios and simple structure. However, these devices are unsuitable for cross-point architectures because of the difficulty in controlling the random filament formation that results in large fluctuations in the threshold voltage during operation. In this study, we investigated the unidirectional threshold transition characteristics associated with an Ag/GST/HfOx/Pt-based bilayer selector and demonstrated the occurrence of a low leakage current (< 1 × 10–11 A) and low distribution of the threshold voltage (∆0.11 V). The bilayer structure could control the filament formation in the intermediate state through the insertion of an HfOx tunneling barrier. By stacking a bilayer selector with NiOx-based resistive random-access memory, the leakage and programming currents of the device could be significantly decreased. For the crossbar array configuration, we performed equivalent circuit analysis of a one-selector one-resistor (1S1R) devices and estimated the optimal array size to demonstrate the applicability of the proposed structure. The maximum acceptable crossbar array size of the 1S1R device with the Ag/GST/HfOx/Pt/Ti/NiOx/Pt structure was 5.29 × 1014 (N2, N = 2.3 × 107). [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]

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]

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]

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.

Thin films are the backbone of the electronics industry, and their widespread application in heat sensors, solar cells, and thin-film transistors has attracted the attention of researchers. The current study involves the deposition of a hetero-structured (ZnO/Zn/ZnO) thin film on a well-cleaned glass substrate using the DC magnetron sputtering technique. The samples were then annealed at 100, 200, 300, 400, and 500 °C. The structural, morphological, and electrical characteristics of the annealed samples as well as one as-deposited sample were then examined using atomic force microscopy (AFM), scanning electron microscopy (SEM), X-ray diffraction (XRD), and a Hall effect measuring apparatus. XRD analysis showed a hexagonal ZnO crystal structure for the samples annealed at 300 and 400 °C, whereas the samples annealed at 100 and 200 °C showed metallic zinc and hexagonal ZnO, and the crystallinity decreased for the sample annealed at 500 °C with pure hexagonal crystal symmetry. According to the AFM study, as the annealing temperature increases, the average roughness (Ra) decreases. Temperature has an inverse relationship with particle size. The optimal annealing temperature was determined to be 400 °C. Over this temperature range, the average roughness and particle size increased. Similarly, when Ra decreased, the conductivity increased and the resistance decreased. A fundamental difficulty is that the heating of the heterostructure to 400 °C melts the Zn-based intermediate layer, which alters the Zn phase and disrupts the sample homogeneity.

In this study, the effect of annealing and substrate conditions on the ferroelectricity of undoped hafnium oxide (HfO2) was analyzed. Hafnium oxide was deposited on various substrates such as platinum, titanium nitride, and silicon (Pt, TiN, Si) through RF magnetron sputtering. Annealing was performed in a nitrogen atmosphere at temperatures ranging from 400 to 600 °C, and the process lasted anywhere from 1 to 30 min. As a result, it was confirmed that the orthorhombic phase, the main cause of ferroelectricity, was dominant after a post-anneal at 600 °C for 30 min. Additionally, it was observed that interface mixing between hafnium oxide and the substrate may degrade ferroelectricity. Accordingly, the highest remanent polarization, measured at 14.24 μC/cm2, was observed with the Pt electrode. This finding was further corroborated by piezo force microscopy and endurance tests, with the results being significant compared to previously reported values. This analysis demonstrates that optimizing substrate and annealing conditions, rather than doping, can enhance the ferroelectricity of hafnium oxide, laying the foundation for the future development of ferroelectric-based transistors.

In this study, a low-cost, scalable and robust process is proposed as an innovative method for coating solar mirrors with a self-cleaning, transparent in the full solar range and versatile material based on auxetic aluminum nitrides, previously obtained at the laboratory scale. This work presents the scaling-up of the fabrication process from the laboratory to prototypal scale and the preliminary results of outdoor self-cleaning solar mirror field tests in the demonstrative concentrating solar power (CSP) plant ENEASHIP located in Casaccia (Rome) ENEA Research Center. Prototypes with a size of 50 × 40 cm have shown stability in external conditions: no coating degradation occurred during the test campaign. Their washing restores the initial reflectance affected by soiling and the self-cleaning performance allows for the utilization of a reduced quantity of water for cleaning operations with respect to the uncoated glass of back surface mirrors. A similar self-cleaning AlN coating could be utilized on other solar components affected by soiling, such as the glass envelopes in heat-collecting elements, PV panels and other parts where a self-cleaning performance combined with an optical one is required.

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.