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Resistive Random Access Memory (RRAM) is considered one of the most promising candidates for big data storage. By using atomic layer deposition and magnetron sputtering, HfO2 thin films were prepared on ITO first, which exhibited good resistive switching (RS) characteristics in the structure of Ag/HfO2/ITO. By analyzing the RS mechanism, it is found that both metal conductive filaments and oxygen vacancy conductive filaments coexisted and Sn ion in ITO can influence the retention of RRAM. Furthermore, a device in the structure of Ag/HfO2/Pt was proposed and prepared, which exhibited excellent RS characteristics, including an ultrahigh switching ratio averaging up to 108 and low operating voltage. It is concluded that the difference in the work function between the top and bottom electrodes contributes to improving the switching ratio, reducing the operating voltage. In addition, the Ag/HfO2/Pt device is similar to the Ag/HfO2-based threshold switching selector in the structure and in characteristics of high switching ratio, besides non-volatile memory. Hence, the device is functionally equivalent to the combination of an RRAM and a threshold switching selector. It is the potential way to replace the conventional 1S1R structure memory. [ABSTRACT FROM AUTHOR]

Ferroelectric strontium barium niobate (SrxBa1−xNb2O6 or SBN) is a material with high electro-optic (EO) response. It is currently of interest in low voltage silicon-integrated photonics (SiPh). We have grown strongly textured SBN films with x = 0.65 by radio frequency sputtering on (100)-oriented SrTiO3 substrates where grains with mixed (310) and (001) out-of-plane orientation form. For these mixed orientation films, we observed a maximum effective EO coefficient of 230 pm/V using a transmission EO measurement geometry that is responsive only to the in-plane polarization component coming from the (310)-oriented grains. We also demonstrate that by growing SBN on TiO2-terminated SrTiO3 substrates, we can obtain predominantly (001)-oriented SBN films with out-of-plane polarization. Transmission EO measurements on such (001)-oriented films show a reduced effective Pockels coefficient of 88 pm/V, which is consistent with the overall ferroelectric polarization becoming out-of-plane. This work shows that controlling substrate termination is effective in controlling the grain orientation of SBN films grown on top and that one can readily integrate SBN films on SrTiO3-buffered Si for use in SiPh. [ABSTRACT FROM AUTHOR]

In this study, we developed a hybrid machine learning technique by combining appropriate classification and regression models to address challenges in producing high-mobility amorphous In2O3:Sn (a-ITO) films, which were fabricated by radio-frequency magnetron sputtering with a nitrogen-mediated amorphization method. To overcome this challenge, this hybrid model that was consisted of a support vector machine as a classification model and a gradient boosting regression tree as a regression model predicted the boundary conditions of crystallinity and experimental conditions with high mobility for a-ITO films. Based on this model, we were able to identify the boundary conditions between amorphous and crystalline crystallinity and thin film deposition conditions that resulted in a-ITO films with 27% higher mobility near the boundary than previous research results. Thus, this prediction model identified key parameters and optimal sputtering conditions necessary for producing high-mobility a-ITO films. The identification of such boundary conditions through machine learning is crucial in the exploration of thin film properties and enables the development of high-throughput experimental designs. [ABSTRACT FROM AUTHOR]

PVD technologies, including vacuum arc evaporation and DC-magnetron sputtering, have been utilized in industrial settings since the early 1980s for depositing protective coatings. These coatings encompass a range of materials such as metal nitrides, carbonitrides, oxides, oxynitrides, and DLC, serving diverse applications such as cutting and forming tools, automotive components, and decoration. Vacuum arc evaporation generates a highly energized and ionized particle flux toward the substrate, while "classical" gas-ion-dominated direct current magnetron sputtering (DCMS) has limitations in generating ionized and energetic species of the sputtered target material. The development of High-Power Impulse Magnetron Sputtering (HiPIMS) has exhibited significant potential in addressing DCMS's limitations by enabling the production of highly energetic particles. This innovation, with its industrial applicability for protective coatings, was introduced around 2010. This paper aims to provide an industrial perspective on HiPIMS, serving as a guide for scientists and engineers in comprehending and implementing HiPIMS solutions. It covers historical context and fundamental characteristics. Basic features as well as state-of-the-art configurations of PVD systems are also described. Graphical representations of experimental results illustrate HiPIMS features, including operational modes, deposition rate effects, thickness uniformity, and sustainability, particularly in terms of energy efficiency. The discussion focuses on the application prospects, advantages, and constraints of industrially applied HiPIMS protective coatings, emphasizing cutting and forming tools, within the context of the findings presented. [ABSTRACT FROM AUTHOR]

A microwave-hot air belt dryer (MHABD) showed high specific energy consumption (SEC) due to its limited material processing capacity and extended drying time. Thus, this research presents the development and performance evaluation of an industrial microwave-hot air belt dryer (IMHABD) for drying Namdokmai Sithong mango slices. The IMHABD system, optimized using the COMSOL Multiphysics program, features a 0.9 m × 4.08 m × 0.5 m chamber with 36 magnetrons having a maximum microwave power of 28,800 W (each magnetron produces 800 W) at a frequency of 2,450 MHz. Two drying methods were studied, step-down microwave power drying (IMHABD-S) and constant microwave power drying (IMHABD-C). IMHABD-S, with a power range of 150–350 W combined with hot air at 65 °C, outperformed IMHABD-C, delivering enhanced drying rates, improved color attributes, and reduced shrinkage, along with decreased hardness and toughness values. All dried slices had a water activity lower than 0.6. An IMHABD-S operated at 350 W for 1.5 h showed the lowest SEC. Economic analysis revealed strong support for the IMHABD process, with a net present value (NPV) of 13,647 USD, an internal rate of return (IRR) of 15%, and a 4.95-year payback with a 10-year service life, highlighting its technical efficacy and economic viability for mango drying applications. [ABSTRACT FROM AUTHOR]

The glow-to-arc transition is a critical phenomenon in plasma discharges, commonly leading to detrimental effects. The physical mechanisms triggering this transition remain poorly understood. The advent of a discharge called Hyper-Power Impulse Magnetron has opened possibilities. Hyper-Power Impulse Magnetron allows the glow mode to be maintained over long periods (1 ms) and at high-current densities (>5 A . cm − 2 ), which has unveiled certain features in the glow-to-arc transition. This work focuses on a graphite target that transits easily in the arc regime. The high-speed video-camera analysis revealed specific properties of graphite in ExB discharges, and the statistical study of the arc transition revealed differences from other refractory target materials. The early stage of cathodic spot formation, observed as bright dots, will be presented and analyzed within the known "ecton" and "vaporization" models for spot formation. This experimental study highlights the role of luminous spot formation prior to arc transition, with possible optimization on the stability of magnetron discharges. [ABSTRACT FROM AUTHOR]

A triode inverse magnetron injection gun (IMIG) for a Ka-band gyrotron traveling wave tube (gyro-TWT) with non-superconducting magnet is proposed in this paper. Nowadays, the applications of gyro-TWT are intended to expand to moveable and fast-startup systems, so room-temperature magnet and system miniaturization are necessary. For a Ka-band gyro-TWT, to adapt to a room-temperature magnet with 20 mm bore radius, the IMIG form is adopted. Compared with conventional MIG, the gun maximum radius is reduced by 44%. On one hand, a curved emitter and cathode steps are utilized for better beam quality. On the other hand, isolation gaps and a cooling structure are designed to suppress stray electrons. A velocity ratio of 1.14 and a transverse velocity spread of 2.43% are obtained finally. The stray electrons are analyzed, and the IMIG tolerance is also evaluated. Finally, the cathode is fabricated, and its surface morphology is tested. It is then assembled into a gun shell, and the cathode temperatures are measured under both no cooling and cooling conditions. When the temperature of the emitter reaches 1050 °C, the heat powers are 84 and 115 W, respectively. The temperatures of the inner and outer electrodes are low enough to reduce the proportion of stray electrons. [ABSTRACT FROM AUTHOR]

Since its invention in 1921 by Hull, magnetrons have undergone rapid development, transitioning from low-power devices to high-power relativistic magnetrons (RMs). However, research on RMs has been predominantly confined to L-X bands until now. To explore the potential of RM in higher frequency bands and align with the trend toward miniaturization of high-power microwave sources, a Ku-band RM has been investigated in this paper. Theoretical analysis dictates the selection of 24 cavities for optimal performance at a low magnetic field. Utilizing a three-dimensional particle-in-cell simulation platform, we demonstrate that the RM can generate a microwave power of 116 MW at a resonant frequency of 13.717 GHz with an electron beam of 126 kV and 2.0 kA, under a magnetic field of 0.22 T, corresponding to a power conversion efficiency of 46%. The integration of a modified all-cavity axial extraction structure in the Ku-band RM allows for a minimized inner radius of the magnetic field system to approximately 25 mm, while maintaining a high-power microwave output. [ABSTRACT FROM AUTHOR]

Glow discharges are known to be limited for running at high current densities (typically below 0.1 A ⋅ c m − 2 ). Magnetically enhanced plasmas overcome this limitation, reaching up to two orders of magnitude higher current densities. However, the highest reported discharge current density hardly reaches 10 A ⋅ c m − 2 even in high power impulse magnetron sputtering (HiPIMS). Here, we report on the long (∼1 ms) pulsed operation of the magnetron in helium with an over-dense current (∼30 A ⋅ c m − 2 , usual for arcs) while preserving the glow mode. This regime defying the arcs was called hyper power impulse magnetron (HyPIM) because the power injected per pulse is several times higher than in HiPIMS for the same average power and pulse duration. HyPIM operation mode is distinguished from HiPIMS by the limited pulse voltage and is unsuitable for thin film deposition but may interest plasma switches. These huge currents were obtained for two cathode materials, molybdenum (Mo) and tungsten (W). Different experimental diagnostics bring insights into the physical phenomena governing the HyPIM plasma. A discussion on the role played by the metal atoms on the current unveils the origin of such exceptional glow current all along the pulse and the key role of the helium metastable atoms. A schematic of the kinetic steps of the HyPIM discharge is proposed. [ABSTRACT FROM AUTHOR]

This article is devoted to the study of microwave-absorbing properties of Co-C coating applied by magnetron sputtering. This article presents the main results of the manufacturing of a Co-C coating by magnetron sputtering, and the evaluation of experimental and computational research data on the relationship between the structure and properties of the obtained films. The structure of Co-C systems has been modeled to control the resulting structures using X-ray diffraction analysis. The structural-phase state of the resulting thin-film Co-C systems and the microwave-absorbing properties of coatings were studied using the transmission line method, consisting of a vector network analyzer, an air coaxial line, a software program, and an external computer. It has been established that on the resulting Co-C film the reflection coefficient in the frequency range of 8.2–12.4 GHz varies in the range of 900 → 718 mU, with reflection losses of −0.86 → −2.57 dB, and a standing wave coefficient of 19 → 6.8. An analysis of the obtained data indicates the presence of losses of electromagnetic energy in the studied frequency range. [ABSTRACT FROM AUTHOR]

Rotating plasma structures, or "spokes," in magnetized discharges characterized by perpendicular electric and magnetic fields have been seen in a growing number of studies and are believed to be the result of gradient-driven drift instabilities. Under certain conditions, we have shown [Ito and Cappelli, Appl. Phys. Lett. 94, 211501 (2009)] the spoke's rotation to be opposite to the E × B direction, i.e., retrograde in its expected direction. Recently [Marcovati et al., J. Appl. Phys. 127, 223301 (2020)], we have linked such counter-intuitive rotation to a local inversion of the electric field. Here, we give further experimental evidence for this inversion and attempt to provide an explanation for a relatively distinct transition seen between retrograde and positive (prograde) drift. In the experiments, a partially magnetized plasma forms inside a magnetron device of ≈ 10 mm radius operated with argon. Discharge current–voltage measurements are acquired for a range of argon fill pressure and inter-electrode spacing. We find two branches of operation—a low current branch of negative resistance, coinciding with the retrograde spoke rotation, and a higher current branch of positive resistance, coincident with prograde spoke rotation. We postulate that at low discharge currents, high magnetic field confinement leads to a large density gradient, causing more electron transport to the anode than that demanded by the external circuit. At higher currents, anomalous axial electron transport (across the magnetic field lines) becomes dominant, eliminating the conditions for field inversion. The current thresholds for the field inversion are found to be sensitive to the argon pressure and inter-electrode spacing. [ABSTRACT FROM AUTHOR]

As a result of enormous progress in nanoscale electronics, interest in artificial intelligence (AI) supported systems has also increased greatly. These systems are typically designed to process computationally intensive data. Parallel processing neural network architectures are particularly noteworthy for their ability to process dense data at high speeds, making them suitable candidates for AI algorithms. Due to their ability to combine processing and memory functions in a single device, memristors offer a significant advantage over other electronic platforms in terms of area scaling efficiency and energy savings. In this study, single-layer and bilayer metal–oxide HfO x and TiO y memristor devices inspired by biological synapses were fabricated by pulsed laser and magnetron sputtering deposition techniques in high vacuum with different oxide thicknesses. The structural and electrical properties of the fabricated devices were analysed using x-ray reflectivity, x-ray photoelectron spectroscopy, and standard two-probe electrical characterization measurements. The stoichiometry and degree of oxidation of the elements in the oxide material for each thin film were determined. Moreover, the switching characteristics of the metal oxide upper layer in bilayer devices indicated its potential as a selective layer for synapse. The devices successfully maintained the previous conductivity values, and the conductivity increased after each pulse and reached its maximum value. Furthermore, the study successfully observed synaptic behaviours with long-term potentiation, long-term depression (LTD), paired-pulse facilitation, and spike-timing-dependent plasticity, showcasing potential of the devices for neuromorphic computing applications. [ABSTRACT FROM AUTHOR]

In a recent publication [J. Appl. Phys. 131, 023301 (2022)], microwave generation by a segmented A6 S-band axial output relativistic magnetron (RM) fed by a split cathode and powered by a small pulsed power generator was demonstrated for the first time. In the present article, we add to the same RM a mode converter and an antenna and drive it by using a modified linear induction accelerator (LIA) (≤450 kV, ≤4 kA, ∼150 ns). It was found that the operation of the RM for a split cathode or a common explosive emission cathode differs significantly. For a split cathode, we optimize for the best microwave output, its geometrical parameters, the external magnetic field, and the LIA's charging voltages. For the optimal choice of these parameters, the RM generates ∼160 ns long microwave pulses of ∼130 MW, 1.78 GHz frequency with an electronic efficiency of ∼40%, without pulse shortening. On the other hand, a common solid cathode fed RM showed microwave pulse shortening. We demonstrated that the segmented anode allows using a μs-timescale magnetic field, making it possible for the RM to operate repetitively. [ABSTRACT FROM AUTHOR]

The composition space Na2O-ZrO2-SiO2-P2O5 was explored using thin film material libraries and high-throughput characterization methods. The combinatorial synthesis comprised non-reactive magnetron co-sputtering at room temperature from two elemental targets Zr and Si, and a compound Na3PO4 target followed by a two-step annealing process. The NASICON phase formed for all compositions on the material library produced at the optimized deposition parameters, also displaying a phase-pure Na1+xZr2SixP3−xO12 (x = 0.4—2.9) region. Analytical TEM analysis of the NASICON phase at a measurement area with stoichiometric composition revealed a fine-grained microstructure and homogeneous Si distribution, in contrast to Na-P excess conditions, where large Si-free NASICON grains have formed. [ABSTRACT FROM AUTHOR]

Entropic stabilization of the crystal structure of solids was demonstrated for various systems, starting with metals and continuing with oxides, nitrides, borides, and more complex structures. The influence of additional thermodynamic driving forces sometimes allow to stabilize the material in a crystalline configuration that is unusual for it. In this paper, we focused on the HfZrCeYMgO system, which has shown excellent mechanical properties and a stable crystal structure. We added different concentrations of aluminum oxide, but found that even in significant quantities, it was embedded in the lattice without separating into separate phases. At the same time, we found that the addition of aluminum significantly increases the crystallinity of the coating as well as its mechanical characteristics. We associate the increase in coating crystallinity with a consistent increase in the entropy of mixing in the HfZrCeYMgAlO system. [ABSTRACT FROM AUTHOR]

One particularly interesting approach for the deposition of highly pure nanoparticles (NPs) in a solvent‐ and surfactant‐free process is the gas phase synthesis of nanoparticles using a gas aggregation source (GAS) based on magnetron sputtering. Apart from the possibility of tuning the NP size‐distribution via process parameters, e.g., gas flow, pressure, and aggregation length, multicomponent targets in a GAS enable in operando composition tuning of alloy NPs. However, in the practical application of the GAS, two main challenges have to be addressed: low target utilization and low conversion efficiency. This work describes a magnetron with a concentrically moveable erosion zone (cMEZ magnetron), and showcases its applicability for the deposition of metal (Cu) and metal alloy (CuNi) NPs via GAS. The cMEZ magnetron relies on an in operando reconfigurable outer magnet array, which enables tuning of the position of the erosion zone, impacting target utilization. By weighting the targets and substrates before and after deposition, the conversion efficiency is determined for different operating pressures and magnet configurations. Furthermore, the multicomponent target approach is tested with the cMEZ magnetron, which enabled the in operando composition tuning of the Ni content in CuNi NPs from ≈5 to ≈35 at% only by varying the magnetic field. [ABSTRACT FROM AUTHOR]

Photocatalysis technology, as an efficient and safe environmentally friendly purification technique, has garnered significant attention and interest. Traditional TiO2 photocatalytic materials still face limitations in practical applications, hindering their widespread adoption. The research prepared TiO2/Cu films with different Cu contents using a magnetron sputtering multi-target co-deposition technique. The incorporation of Cu significantly enhances the antibacterial properties and visible light response of the films. The effects of different Cu contents on the microstructure, surface morphology, wettability, antibacterial properties, and visible light response of the films were investigated using an X-ray diffractometer, X-ray photoelectron spectrometer, field emission scanning electron microscope, confocal laser scanning microscope, Ultraviolet–visible spectrophotometer, and contact angle goniometer. The results showed that the prepared TiO2/Cu films were mainly composed of the rutile TiO2 phase and face-center cubic Cu phase. The introduction of Cu affected the crystal orientation of TiO2 and refined the grain size of the films. With the increase in Cu content, the surface roughness of the films first decreased and then increased. The water contact angle of the films first increased and then decreased, and the film exhibited optimal hydrophobicity when the Cu target power was 10 W. The TiO2/Cu films showed good antibacterial properties against Escherichia coli and Staphylococcus aureus. The introduction of Cu shifted the absorption edge of the films to the red region, significantly narrowed the band gap width to 2.5 eV, and broadened the light response range of the films to the visible light region. [ABSTRACT FROM AUTHOR]

To elucidate the effects of energy input modes on energy efficiency and berry quality in continuous microwave drying, four energy input modes with variational working ways of magnetrons were investigated by using numerical simulation and bench experiments in a continuous microwave dryer. Energy efficiency was divided into absorption and conversion efficiency to study the change rule of drying process, and the retention rate of anthocyanins of berry's representative nutrition ingredient was studied considering both of the temperature and its uniformity. Results indicate that the energy input modes affect the absorption efficiency by changing the distribution uniformity of electric field of material layer, and the conversion efficiency by altering the matching degree between the energy allocation and drying characteristics of berry, which are both determined by the ways of working magnetrons of different energy input modes. The conversion efficiency has a greater influence on the final energy efficiency, so the energy input mode should be paid attention to the provision of microwave energy by selecting proper way of working magnetrons according to the drying characteristics. The effect of temperature uniformity on anthocyanin degradation is more obvious with average temperature increasing gradually, where better uniformity of electric field strength should be provided to guarantee the quality of dried berry by adjusting the energy input mode. The research results provide significant insights to optimize the energy input mode of taking into account both the energy efficiency and dried quality of material. [ABSTRACT FROM AUTHOR]

Indium tin oxide (ITO) is a transparent conductive oxide (TCO) commonly used in the realization of optoelectronic devices needing at least a transparent electrode. In this work, ITO thin films were deposited on glass substrates by non-reactive RF magnetron sputtering, investigating the effects of power density, sputtering pressure, and substrate temperature on the electrical, optical, and structural properties of the as-grown films. High-quality films, in terms of crystallinity, transparency, and conductivity were obtained. The 120 nm thick ITO films grown at 225 °C under an argon pressure of 6.9 mbar and a sputtering power density of 2.19 W/cm2 without post-annealing treatments in an oxidizing environment showed an optical transmittance near 90% at 550 nm and a resistivity of  2.10 × 10 − 4   Ω  cm. This material was applied as the electrode of simple-structure organic light-emitting diodes (OLEDs). [ABSTRACT FROM AUTHOR]

Being the most widely applied thermoelectric materials near room temperature, (Bi,Sb)2Te3 alloys have to face the performance deterioration above 400 K due to their intrinsic narrow bandgap. Increasing the dominant hole concentration and expanding the bandgap have been proven as effective strategies to suppress bipolar excitation through elemental substitution and nanoscale compositing. Herein, PbTe-incorporated Bi0.5Sb1.5Te3 thin films were deposited on flexible polyimide substrates through intermittent magnetron cosputtering. The introduction of tiny amount of PbTe was found to have significant influences on the microstructure and orientation, atomic compositions, and carrier concentration. Profiting from the enhanced carrier concentration and altered effective mass, the descending in Seebeck coefficient above 400 K can be effectively inhibited, accompanied with the distinctly improved electrical conductively. Finally, the highest power factor of 16.38 μW cm−1 K−2 at 420 K and the highest average power factor of 14.62 μW cm−1 K−2 in the temperature range of 300–540 K were obtained in the Bi0.5Sb1.5Te3/PbTe composite film containing 0.25% Pb, with the increments of 28.2% and 38.2% from those of the PbTe-free Bi0.5Sb1.5Te3 film, respectively. These values are competitive among the flexible Bi0.5Sb1.5Te3 thin films fabricated from the scalable routes. [ABSTRACT FROM AUTHOR]

The paper focuses on magnetron sputtering of the pure calcium target in DC magnetron discharge. The target diameter and thickness are 50 and 3 mm, respectively. Argon and krypton are used as working gases. Continuous and medium frequency discharges are investigated along with the discharge and plasma parameters, including a current–voltage characteristic, mass-to-charge ratio of the plasma composition, ion current, and deposition rate. [ABSTRACT FROM AUTHOR]

A preliminary investigation of the optical properties of complex Cr-based hard coatings and their connection with the compound structure of the coatings is presented. Cr/CrN, Cr/CrN/CrAlN, Cr/CrN/CrTiAlN, and Cr/CrN/CrAlTiN coating structures were deposited through unbalanced magnetron sputtering. Their mechanical properties, especially nanohardness, coefficient of friction, and adhesion, were measured. The structure and composition of the coatings were characterised through SEM, FIB, XPS, and TEM. Their optical properties were investigated by UV-VIS ellipsometry. The optical parameters' phase difference Δ, the amplitude ratio Ψ, the frequency-dependent real (ε1(ω)) and imaginary (ε2(ω)) part of the dielectric function, and the corresponding refractive and extinction indexes n(ω) and k(ω) were measured and modelled via regression analysis implemented using the WVASE© software version 3.686. Satisfactory coincidence was achieved between the measured optical data and the corresponding fitting models. The physical polycrystalline optical constants of the industrial samples were extracted from modelling data with roughness. The analysis of the data showed that ellipsometric characterisation can be used in order to determine the physical properties of Cr-based hard coatings with complex structure and composition, as well as for repeatability control of the deposition process. However, more detailed research is needed to predict the composition based on measured optical properties. [ABSTRACT FROM AUTHOR]

The features of the probe technique are described and the results of measuring the parameters of plasma generated by a planar magnetron sputtering system with a pure boron target during coating deposition are presented. A feature of probe measurements was the use of heating the collecting surface of a single Langmuir probe. Heating led to a decrease in the electrical resistance of the boron film on the surface, which made it possible to carry out in situ probe measurements of the magnetron discharge plasma parameters during the entire process of boron coating. [ABSTRACT FROM AUTHOR]

Sn-doped Ga2O3 thin films and metal–semiconductor–metal (MSM) ultraviolet detectors were prepared using the co-sputtering method to enhance their photoelectric performance. The results revealed that Sn doping can effectively change the optical and electrical properties of thin films, greatly improving the photoelectric responsiveness of the devices. Through microstructure testing results, all of the thin film structures were determined to be monoclinic beta phase gallium oxide. At a DC power of 30 W, the thickness of the Sn-doped thin film was 430 nm, the surface roughness of the thin film was 4.94 nm, and the carrier concentration, resistivity, and mobility reached 9.72 × 1018 cm−3, 1.60 × 10−4 Ω·cm, and 45.05 cm3/Vs, respectively. The optical results show that Sn doping clearly decreases the transmission of thin films and that the bandgap can decrease to 3.91 eV. Under 30 W DC power, the photo dark current ratio of the detector can reach 101, time responses of tr = 31 s and tf = 22.83 s were obtained, and the spectral responsivity reached 19.25 A/W. [ABSTRACT FROM AUTHOR]

Stimulated by the pursuit of small and portable electronic devices, film supercapacitors have gradually developed. Due to the advantages of composition design and controllable performance, high entropy materials have shown excellent capacitive performance in electrochemical energy storage. Therefore, in this work, five transition metal elements Fe, Co, Cr, Mn and Ni were selected with different potential windows, and the (FeCoCrMnNi)C thin films with wide potential windows were successfully deposited on titanium and graphite substrates by using magnetron sputtering technology. The body centered cubic structured (FeCoCrMnNi)C films all have crystal orientation, showing irregular particle morphology, and the optimal orientation makes them eventually grow into morphologies similar to those of the substrates. The layered structure of the (FeCoCrMnNi)C film deposited on graphite substrate for 10 min is the most conducive to the storage of pseudocapacitance. We also found that (FeCoCrMnNi)C powder has better electrochemical properties than (FeCoCrMnNi)C film in the two low-dimensional states of the (FeCoCrMnNi)C, which is of great significance for exploring the development direction of supercapacitor electrode materials in the future. [ABSTRACT FROM AUTHOR]

Boron carbide coatings deposited by sputtering with conventional planar magnetrons exhibit nodular growth defects. Here, we demonstrate that the density of nodular defects in B 4 C films can be greatly reduced by using a full-face-erosion magnetron source that achieves a more uniform target erosion by sweeping the confining magnetic field over the target surface. We systematically study properties of B 4 C films deposited on substrates with different tilt angles and demonstrate deposition of ultrathick films with compressive residual stress below 200 MPa. [ABSTRACT FROM AUTHOR]

Improving the properties of metallic bipolar plates is very crucial for high performance of proton exchange membrane fuel cells (PEMFCs). Cr–C films are prepared on the stainless steel 316L substrate by RF multi-point magnetron co-sputtering of Cr sheets and graphite target for the first time. Effect of the number of Cr sheets on the morphology, composition, corrosion resistance, conductivity, and hydrophobicity of Cr–C films are investigated systematically. With the increase of the number of Cr sheets, the ratio of sp2/sp3 hybrid in the Cr–C films is decreased, and the films become more compact and smoother. When the number of Cr sheets is 8, the ratio of sp2/sp3 hybrid is 5.01, and the Cr–C film shows the best comprehensive performance. The corrosion current densities of anode and cathode are 0.31 μA cm−2 and -0.087 μA cm−2 at constant potential, respectively, and 0.229 μA cm−2 and -0.276 μA cm−2 at galvanic potential, respectively. The corrosion resistance property of the Cr–C film is superior to DOE standards. Compared with uncoated 316L stainless steels, the properties of corrosion resistance, conductivity, and hydrophobicity of the ones coated with the Cr–C films have been improved significantly. This work opens up a new way for the preparation of metal bipolar plate films. • A method for RF multi-point magnetron co-sputtering is proposed. • The effect of the number of sheet on the properties of CrC films is studied. • CrC films with excellent corrosion resistance and hydrophobicity are prepared. • The films deposited with the number of 8 Cr sheets has the best performance. [ABSTRACT FROM AUTHOR]

Thin manganese silicide films were obtained on mica by magnetron sputtering from targets of three types. The microstructure and elemental composition of the targets and films were studied by scanning electron microscopy and reflection electron diffraction. The phase composition and structure of the films over depth (cuts) were controlled by scanning and transmission electron microscopy. It has been shown that, when depositing films from poly- and single-crystal targets of higher manganese silicide, in contrast to a target from sintered Мn and Si powders, one can obtain polycrystalline films of higher manganese silicide of the Mn4Si7 composition after subsequent 1-h annealing at a temperature of 800 K and a pressure of 10–3 Pa. [ABSTRACT FROM AUTHOR]

In this paper, the aging characterization of a kind of insulating paper modified by magnetron sputtering MgO particles based on a microstrip resonant sensor was presented. Firstly, the modified insulating paper with 0, 15 and 30 min MgO particle sputtering times was prepared by a magnetron sputtering device. After that, the properties of the modified insulating paper with different sputtering times were analyzed through microscopic characterization, infrared spectrum, polymerization degree, dielectric constant, AC breakdown strength and thermal aging experiments. The results show that the dielectric constant of the modified insulating paper decreased obviously, the AC breakdown strength increased and the thermal aging resistance was better after 15 min of sputtering. The overall performance of the modified insulating paper after 30 min of sputtering is reduced due to excessive sputtering. In addition, microstrip resonant sensors are introduced to characterize the thermal aging degree of the modified insulating paper, and two microstrip resonant sensors are prepared: a complementary split ring resonator (CSRR) and an interdigital-capacitor-shaped defected ground structure resonator (IDCS-DGS). The resonance frequency deviation of the modified insulating paper samples after aging was measured by microstrip resonance sensors to show the influence of aging temperature on aging degree. The experimental results show that the test results of the microstrip resonance sensors are in good agreement with the traditional characterization methods and can characterize the various aging stages of the modified insulating paper to a certain extent, which proves the feasibility of the characterization method. [ABSTRACT FROM AUTHOR]

High-throughput methods are extremely important in today's materials science, especially in the case of thin film characterization. The micro-combinatorial method enables the deposition and characterization of entire multicomponent thin film systems within a single sample. In this paper, we report the application of this method for the comprehensive TEM characterization of the Y-Ti-O layer system. Variable composition samples (YxTi1−xOy) were prepared by dual DC magnetron sputtering, covering the entire (0 ≤ x ≤ 1) concentration range. The structure and morphology of phases formed in both as-deposited and annealed samples at 600, 700, and 800 °C were revealed as a function of Y-Ti composition (x). A comprehensive map showing the appropriate amorphous and crystalline phases, and their occurrence regions of the whole Y-Ti-O layer system, was revealed. Thanks to the applied method, it was shown with ease that at the given experimental conditions, the Y2Ti2O7 phase with a pyrochlore structure forms already at 700 °C without the TiO2 and Y2O3 by-phases, which is remarkably lower than the required temperature for most physical preparation methods, demonstrating the importance and benefits of creating phase maps in materials science and technology. [ABSTRACT FROM AUTHOR]

To address the inherent power limitations in a single relativistic magnetron (RM), we explore the feasibility of coupling multiple phase-locked RMs without compromising power conversion efficiencies. Successful phase locking of two coupled A6 RMs, where radiations are axially extracted as TE11 modes, has been achieved. The interaction between the two RMs is facilitated by a well-designed waveguide with a transmission coefficient exceeding 98% in the L-band. In our designed system, as per the particle-in-cell simulation results with a diode voltage of 560 kV, the RMs' peak power of the Gaussian radiation pattern reaches approximately 3.4 GW. The relative phase jitter between these two tubes is effectively controlled within ±1.6%, and the power conversion efficiency reaches up to 48.1%. This study presents a viable approach to enhance the output power of RMs while maintaining phase-locked Gaussian radiation patterns. [ABSTRACT FROM AUTHOR]

Two-dimensional metals have gained great attention in recent years. However, most of these metals possess relatively strong chemical bonding in three directions; therefore, it is difficult to synthesize 2D metals. In this paper, we prepared 2D and thin- film copper materials via magnetron sputtering. 2D and thin-film copper are formed due to the accumulation of strain and stress associated with different coefficients of thermal expansion for the metal and substrate. SEM and AFM studies suggest that the minimum thickness of a freestanding single layer is approximately 1 nm, with lateral dimensions up to a few millimeters. [ABSTRACT FROM AUTHOR]

p-type Ag-N dual acceptor doped ZnO thin films with long electrical stability were deposited by DC magnetron reactive co-sputtering technique. After deposition, the films were annealed at 400 °C for one hour in a nitrogen-controlled atmosphere. The deposited films were amorphous. However, after annealing, they crystallize in the typical hexagonal wurtzite structure of ZnO. The Ag-N dual acceptors were incorporated substitutionally in the structure of zinc oxide, and achieving that; the three samples presented the p-type conductivity in the ZnO. Initial electrical properties showed a low resistivity of from 1 to 10−3 Ω·cm, Hall mobility of tens cm2/V·s, and a hole concentration from 1017 to 1019 cm−3. The electrical stability analysis reveals that the p-type conductivity of the ZnO:Ag,N films is very stable and does not revert to n-type, even after 36 months of aging. These results reveal the feasibility of using these films for applications in short-wavelength or transparent optoelectronic devices. [ABSTRACT FROM AUTHOR]

Thermochromic vanadium dioxide (VO2) undergoes a reversible semiconductor‐to‐metal transition, a property that can be exploited for reduction of the energy consumption in buildings using smart windows. Herein, high‐performance thermochromic three‐layer ZrO2/V0.98W0.02O2/ZrO2 coatings prepared on ultrathin flexible glass (0.1 mm) without any post annealing in a pilot‐scale roll‐to‐roll deposition device are presented. The V0.98W0.02O2 layers are deposited using a reactive high‐power impulse magnetron sputtering with an oxygen flow control at a substrate temperature of approximately 350 °C. The optimized coatings (width of 0.3 m and length over 2.6 m) exhibit a transition temperature of 28 °C, an integral luminous transmittance over 50%, and a modulation of the solar energy transmittance of about 10%. The deposition process is optimized, and the elemental composition (Rutherford backscattering spectrometry), design (field‐emission scanning electron microscopy), phase composition (X‐ray diffraction), and thermochromic properties (spectrophotometry) of these high‐performance VO2‐based coatings in the context of potential for commercial applications are characterized. [ABSTRACT FROM AUTHOR]

High-power pulse magnetron sputtering is a new type of magnetron sputtering technology that has advantages such as high peak power density and a high ionization rate compared to DC magnetron sputtering. In this paper, we report the effects of different pulse widths on the current waveform and plasma spectrum of target material sputtering, as well as the structure and properties of Cu films prepared under the same sputtering voltage and duty cycle. Extending the pulse width can make the sputtering enter the self-sputtering (SS) stage and improve the ion quantity of sputtered particles. The Cu film prepared by HiPIMS with long pulse width has higher bond strength and lower electrical resistivity compared to the Cu film prepared by short pulse width. In terms of microstructure, the Cu film prepared by HiPIMS with the long pulse width has a larger grain size and lower micro-surface roughness. When the pulse width is bigger than 200 μs, the microstructure of the Cu film changes from granular to branched. This transformation reduces the interface on the Cu film, further reducing the resistivity of the Cu film. Compared to short pulses, long pulse width HiPIMS can obtain higher quality Cu films. This result provides a new process approach for preparing high-quality Cu films using HiPIMS technology. [ABSTRACT FROM AUTHOR]

The influence of argon working pressure during magnetron sputtering on thermoelectric properties has been investigated on p-type Bi0.5Sb1.5Te3 flexible films deposited at various working pressures in the range from 2 to 5 Pa. The microstructure and orientations, atomic compositions, and carrier concentration could be regulated by adjusting the working pressure, due to the size-dependent inhibition of the deposition of the sputtered Bi, Sb, and Te atoms from argon ions. Profiting from the occurrence of the (006) orientation, the nearest stoichiometric ratio, the highest carrier concentration and mobility, and the quantum confinement effect, the film deposited at 4 Pa displays the maximum power factor of 1095 μW m−1 K−2 at 360 K. These results suggest that the electrical transport properties of the sputtered flexible thermoelectric thin films can be synergistically optimized by selecting an appropriate working pressure. [ABSTRACT FROM AUTHOR]

Controllable and scalable preparation of electrocatalyst materials holds significant importance for their practical application. Magnetron sputtering is a highly effective synthesis method, known for its producing uniform films and allowing easy control of component compositions. In this paper, we propose an in-situ synthesis method for layered double hydroxide (LDH) electrocatalysts through sacrificing magnetron sputtered films. The resulting FeCo-LDH catalyst demonstrated a low overpotential of only 300 mV at 10 mA·cm−2. Furthermore, we conducted spectroscopic analysis to investigate the surface changes of the catalysts during the oxygen evolution reaction (OER) process. Our findings indicated that the formation of Co oxyhydroxides plays a beneficial role in enhancing the catalytical performance of the FeCo-LDH for OER reaction. This restructuring strategy of converting a magnetron-sputtered sacrificial film into a catalytical LDH introduces a new avenue to the synthesis of transition metal-based electrocatalysts. [ABSTRACT FROM AUTHOR]

Solar-blind photodetectors (SBPDs) based on the ultrawide-bandgap semiconductor Ga2O3 have gained attention due to their potential applications in both military and civilian domains. As technology advances, photodetectors are being improved to achieve better energy efficiency, smaller size, and better performance. Solar-blind photodetectors based on a metal-semiconductor-metal structure of amorphous gallium oxide (a-Ga2O3) films were fabricated by pulsed magnetron sputtering deposition (PSD). The photodetector based on amorphous gallium oxide has a responsivity of 71.52 A/W, a fast rising and falling response time of less than 200 ms, a photo-to-dark current ratio (PDCR) of 6.52 × 104, and an external quantum efficiency of 34 526.62%. PSD-prepared gallium oxide SBPDs demonstrate a cost-effective room temperature method for growing gallium oxide and show the advantages of growing gallium oxide. [ABSTRACT FROM AUTHOR]

The cubic zirconia (ZrO2) is attractive for a broad range of applications. However, at room temperature, the cubic phase needs to be stabilized. The most studied stabilization method is the addition of the oxides of trivalent metals, such as Sc2O3. Another method is the stabilization of the cubic phase in nanostructures—nanopowders or nanocrystallites of pure zirconia. We studied the relationship between the size factor and the dopant concentration range for the formation and stabilization of the cubic phase in scandium-stabilized zirconia (ScSZ) films. The thin films of (ZrO2)1−x(Sc2O3)x, with x from 0 to 0.2, were deposited on room-temperature substrates by reactive direct current magnetron co-sputtering. The crystal structure of films with an average crystallite size of 85 Å was cubic at Sc2O3 content from 6.5 to 17.5 mol%, which is much broader than the range of 8–12 mol.% of the conventional deposition methods. The sputtering of ScSZ films on hot substrates resulted in a doubling of crystallite size and a decrease in the cubic phase range to 7.4–11 mol% of Sc2O3 content. This confirmed that the size of crystallites is one of the determining factors for expanding the concentration range for forming and stabilizing the cubic phase of ScSZ films. [ABSTRACT FROM AUTHOR]

This study presents an innovative, statistically‐guided magnetron sputtering technique for creating nanoarchitectonics of high‐performing, NiFeMoN electrocatalysts for oxygen evolution reaction (OER) in water splitting. Using a central composite face‐centered (CCF) design, 13 experimental conditions are identified that enable precise optimization of synthesis parameters through response surface methodology (RSM), confirmed by analysis of variance (ANOVA). The statistical analysis highlighted a interaction between Mo% and N% in the nanostructured NiFeMoN and found optimizing values at 31.35% Mo and 47.12% N. The NiFeMoN catalyst demonstrated superior performance with a low overpotential of 216 mV at 10 mA cm−2 and remarkable stability over seven days, attributed to the modifications in electronic structure and the creation of new active sites through Mo and N additions. Furthermore, the NiFeMoN coating, when used as a protective layer for a Si photoanode in 1 m KOH, achieved an applied‐bias photon‐to‐current efficiency (ABPE) of 5.2%, maintaining stability for 76 h. These advancements underscore the profound potential of employing statistical design for optimizing synthesis parameters of intricate catalyst materials via magnetron sputtering, paving the way for accelerated advancements in water splitting technologies and also in other energy conversion systems, such as nitrogen reduction and CO2 conversion. [ABSTRACT FROM AUTHOR]

Spokes are regions of enhanced ionization in magnetron sputtering discharges that are interesting because of their role for magnetron operation and their potential effect on deposition processes. Here, we show that spokes can intentionally be generated by introducing a strong-to-weak magnetic field strength transition along the racetrack. Spokes are triggered at the transition point from an accelerating electron drift when weakening the magnetic field strength. The spokes are then propagating against the electron drift into the strong magnetic field strength section of the racetrack. At the weak-to-strong magnetic field transition, we observe the inverse effect. The electron drift is decelerated at this point, creating a region of enhanced optical emission. From rectangular racetracks this is known as the cross-corner effect. Here, we show that a corner is not necessary for observing that effect. Pronounced spokes at low working gas pressure of 0.2 Pa exhibit a substructure that could be caused by the diocotron instability previously predicted by computer simulations. [ABSTRACT FROM AUTHOR]

This paper presents a design scheme of a Novel Flattened Magnetron for Household Microwave Oven, which makes a breakthrough in the magnetic circuit of the existing magnetron and adopts the symmetrical enhanced magnetic circuit design scheme. Magnetron width has been successfully reduced from 80 mm to 50 mm. The reduction is up to 37.5%. Based on the size of the flattened magnetic circuit system, the theory of magnetron noise, and the knowledge of LC low-pass filters, a filtering structure for the flattened magnetron is proposed. Electromagnetic simulation shows that the magnetron with the new magnetic circuit structure can still meet the design specifications of the magnetron used in the existing microwave oven. An experiment was conducted to verify the proposed design's performance, and it was found to be similar to the existing conventional magnetron. [ABSTRACT FROM AUTHOR]

This article presents experimental evidence demonstrating the feasibility of implementing a quasi-dual-frequency microwave signal generator using a 1 kW commercial magnetron. The injection-pulled magnetron may generate quasi-dual-frequency output with nearly identical amplitudes by injecting signal at specific powers and frequencies out of the Adler locking band. This generator offers the advantage of developing a large-power and tunable quasi-dual-frequency signal at low cost and with simple implementation. In the present study, a tunable quasi-dual-frequency signal with a frequency interval ranging from 0.48 MHz to 13.74 MHz is generated experimentally. Furthermore, the effects of anode voltage ripples on the dual-frequency outputs are experimentally investigated. An empirical relationship between the frequency interval and injection ratio is obtained and presented. In addition, neither the output power nor the efficiency of the magnetron in the dual-frequency mode decreases. This research is promising for improving microwave heating uniformity in large-scale industrial applications. [ABSTRACT FROM AUTHOR]

This paper presents a new design of a magnetic shunt transformer for use in industrial microwave generators. The proposed transformer has a triangular shape and offers several advantages over existing transformer designs, including reduced volume and maintenance costs. We provide a detailed analysis of the transformer's dimensions and an equivalent model of the three-phase high voltage power supply system. The results of this study have significant implications for the field of industrial microwave generator design and could lead to the development of more efficient and costeffective systems. The resulting model is comprised of saturable inductors capable of accounting for the non-linear phenomena of saturation. The power supply is simulated using MATLAB/Simulink with a neuro-fuzzy ANFIS approach. The results are compared to experimental validations of a single-phase reference power supply for a magnetron, validating the proposed power supply. Additionally, the simulation results demonstrate the effectiveness of the proposed design, which outperforms existing transformers in terms of volume, energy efficiency and maintenance costs. [ABSTRACT FROM AUTHOR]

A microwave-convective dryer for seed grain is considered as an effective drying system that allows reducing energy consumption. It is emphasized that for optimal design and cost-effective operation, as well as proper observance of optimal storage conditions for agricultural products, in particular grain products, it is advisable to use microwave heating with simultaneous blowing of air through the layer and to ensure utilization of air heat from the magnetron cooling system. It was determined that one of the main problems of using a microwave field for processing dense layers of grain is to ensure sufficient uniformity of the distribution of the microwave field. It is emphasized that the use of horn-type waveguides makes it possible to effectively irradiate grain with microwave energy. The scheme of the installation for microwave-convective grain drying is proposed, in which horn antennas are proposed as waveguides, closed with fluoroplastic plates to prevent water vapor from entering the working chamber to the waveguide. The calculations of the cooling system of the anode blocks of magnetrons and the calculation of the grain preheating chamber are presented. The heating medium is air blown through the layer in a horizontal direction at a filtration speed of 0.14 m/s. Based on the calculation of the working chamber of a microwave-convective dryer with a dense layer moving with a flow rate of G = 1,25·10-2 kg/s, the power consumed from the network by magnetrons, taking into account the efficiency of the microwave chamber, and the appropriate number of magnetrons are determined. At the drying rate N = 5,8·10-5 с -1 and using three magnetrons with a total power of 3 kW, the specific consumption per kilogram of evaporated moisture will be 5.3 MJ/kg. The use of a heat recovery system in the preheating chamber reduces energy consumption by 1.3 times. [ABSTRACT FROM AUTHOR]