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In this work, deposition time and RF power was shown to significantly influence the microstructure and properties of silicon carbide (SiC) thin films deposited on aluminum substrates by radio-frequency (RF) magnetron sputtering. Three different deposition times of 40, 60 and 75 min and at RF powers of 90 and 120 W were considered. The surface morphology of the thin films was investigated using an optical profilometer and a scanning electron microscope (SEM). The Vickers hardness test was also used to determine the hardness of the films. Grain size measurements revealed that increasing the deposition time and RF power results in larger SiC grains. Moreover, the surface roughness also increased with deposition time, however a decrease in roughness was observed when the RF power was increased from 90 to 120 W. The hardness of the SiC thin films generally increased with both deposition time and RF power, with the power having a more pronounced effect on the film hardness.

X-ray photoelectron spectroscopy (XPS) confirmed that RF magnetron sputtering of h-BN onto unheated substrates produced a-BOxNy films under all of the sputtering conditions studied. The surface roughness improved and pinholes were eliminated as the deposition pressure increased. Analysis of the current density dependence on the electric field of the a-BOxNy films suggests field-enhanced Schottky emission and/or Frenkel-Poole emission transport mechanisms. The highest breakdown strength obtained was 8 MV cm−1. A bandgap of 3.9 eV was confirmed by spectroscopic ellipsometry and UV–Vis spectroscopy. An interface trap concentration (Nit) of 7.3 × 1010 cm−2 and interface state density (Nss) of 7.5 × 1012 eV−1 cm−2 were measured for transparent ITO/a-BOxNy/ZnO metal–insulator-semiconductor (MIS) structures. Approximately, 2 V was required to switch the a-BOxNy/ZnO interface from accumulation to inversion.

We introduced a phase-locking mechanism of millimeter-wave magnetrons coupled through a carefully designed coupling bridge. For such a structure, two Ka-band 22-vane rising-sun magnetron circuits operated in the $\pi $ -mode were phase-locked tightly as a whole through a double-ridged coupler. Moreover, the double-ridged coupler was optimized to suppress mode competition between zero-phase and $\pi $ -phase difference mode, which achieved high-efficiency phase-locking. Total output power of the two identical magnetrons nearly doubled the output power of a free-running magnetron and efficiencies of them were nearly the same. Extension of this phase-locking mechanism to high-power applications appears feasible with more elements in an array of the millimeter-wave magnetrons.

BaTiO3 (BTO) and NiFe films grown on SrTiO3 (STO), Nb:SrTiO3 (NSTO), and ITO-glass substrates were prepared by radio-frequency (RF) and direct-current (DC) magnetron sputtering, respectively. The microstructure, ferroelectricity, leakage current, magnetoelectric (ME) coupling, ultraviolet–visible light spectrum, optical band gap, ellipsometry spectrum and surface morphology of the composite film are characterized by XRD, ferroelectric analyzer, ME coupling test system, U-4100, Horiba Smart SE and AFM. In addition, the stress, strain and piezoelectric voltage of the magnetoelectric composite film under the action of DC and AC magnetic fields are simulated by COMSOL multiphysics software. The experimental results show that the prepared composite film is polycrystalline, the surface roughness of the film is better, and the particles are uniform. The magnetoelectric coupling voltage gradually increases with the increase of the value of the DC magnetic field and the frequency of the AC magnetic field, and it has a larger absorption (about 0.3) at 340 nm. In addition, the simulation results also show the relationship between the coupling voltage VME and the applied magnetic field H.

Particle-in-cell (PIC) simulations of a microwave oven free-running 2.45 GHz “cooker” ten-vane magnetron operating with a “cold” explosive-emission cathode in a uniform axial magnetic field are performed with two computer codes, improved concurrent electromagnetic PIC (ICEPIC), and CST Particle Studio (CST-PS). PIC simulations are done to compare results obtained by these two codes to each other and, in such a way, identify all possible advantages and disadvantages of each code performance as a reliable tool allowing to predict all important characteristics of the magnetron operation. Results of the PIC simulations show that the range of applied voltages within which the magnetron is able to operate in the $\pi $ -mode at an external uniform axial magnetic field 0.19 T is much broader as it is predicted by the CST-PS code, from 4.00 to 4.70 kV, than as it predicted by the ICEPIC code, from 3.90 to 4.10 kV. It is also shown that while the magnetron startup time gradually decreases, as it is predicted by the ICEPIC code, from about 700 ns (3.90 kV) to about 100 ns (4.20 kV) with the applied voltage increase, it initially chaotically varies, as it is predicted by the CST-PS code, between about 1000 ns (4.03 kV) and about 300 ns (4.01 kV) and only then gradually decreases down to 10–20 ns (4.40–4.60 kV) with the applied voltage increase. Additional PIC simulation with MAGIC or VORPAL codes would be interesting to perform as well to compare the obtained with these codes simulation results with results described in this article.

Thermal oxidation at various temperatures on magnetron sputtered hafnium films shown significant effect on stoichiometry, crystallographic structure and electrical and optical properties. X-ray photoelectron spectroscopy confirms the stoichiometry of HfO2 films by showing the relevant shift in the core level binding energies of hafnium and oxygen after increasing the oxidation temperature to 600 °C. The EDAX analysis also confirmed the required composition of HfO2 films. The presence of monoclinic HfO2 structure was identified by XRD for the films oxidized at 600 °C. The interface quality at HfO2/Si stacks was improved as a function of oxidation temperature. The optical band gap and the refractive index of the HfO2 films increased with increase of oxidation temperature.

In this study, nanocrystalline Ni100-xCux alloy films have been synthesised using DC magnetron co-sputtering under argon gas atmosphere to analyse their superparamagnetic behaviour. The nanocrystal...

In this exploratory work, micrometric radiopaque W–Fe–Mn–C coatings were produced by magnetron sputtering plasma deposition, for the first time, with the aim to make very thin Fe–Mn stents trackable by fluoroscopy. The power of Fe–13Mn-1.2C target was kept constant at 400 W while that of W target varied from 100 to 400 W producing three different coatings referred to as P100, P200, P400. The effect of the increased W power on coatings thickness, roughness, structure, corrosion behavior and radiopacity was investigated. The coatings showed a power-dependent thickness and W concentration, different roughness values while a similar and uniform columnar structure. An amorphous phase was detected for both P100 and P200 coatings while γ-Fe, bcc-W and W3C phases found for P400. Moreover, P200 and P400 showed a significantly higher corrosion rate (CR) compared to P100. The presence of W, W3C as well as the Fe amount variation determined two different micro-galvanic corrosion mechanisms significantly changing the CR of coatings, 0.26 ± 0.02, 59.68 ± 1.21 and 59.06 ± 1.16 μm/year for P100, P200 and P400, respectively. Sample P200 with its most uniform morphology, lowest roughness (RMS = 3.9 ± 0.4 nm) and good radiopacity (∼6%) appeared the most suitable radiopaque biodegradable coating investigated in this study., Graphical abstract Image 1, Highlights • Three W–Fe–Mn–C coatings (P100, P200, P400) were developed by magnetron sputtering. • Coatings showed a columnar structure and power-dependent thickness and W concentration. • Thicknesses from 0.9 ± 0.2 to 1.8 ± 0.2 μm and RMS from 3.9 ± 0.4 to 54.3 ± 8.1 nm were found for P100, P200, P400, resp. • The amorphous phase of P100, P200 and γ-Fe, bcc-W and W3C of P400 significantly affected the CR. • The most uniform morphology, lowest roughness (3.9 ± 0.4 nm) and good radiopacity (∼6%) were found for P200.

In order to enhance the power capacity of gyro-traveling wave tube (Gyro-TWT), a novel multisectorial-tunnel circuit is presented in this article. The multisectorial tunnel could extend the transverse dimension of RF circuit for higher power electron beam transportation. The azimuthal drifting and transportation distortion performance for rotated electron beam are analyzed. A multibeam magnetron injection gun (MIG) is designed. The electron beam with pitch factor of 1.09 and axial velocity spread of 3.5% is obtained. And the designed cathode was fabricated and temperature distribution was measured. It provides a possible method to enhance the power capacity of Gyro-TWT.

One of the main difficulties in designing a relativistic magnetron producing high-power microwaves (HPMs) to be compact, is the power source required to feed the solenoid producing the axial magnetic field, which magnetically insulates the electron beam. This is because the diffusion of the magnetic field through the walls of the system is on the millisecond timescale. The latter requires high-power supplies and restricts the magnetron from operating repetitively. Using permanent magnets instead does not make the system sufficiently compact, because of the size and weight of the magnets and does not allow varying the magnetic field. We suggest a simple solution to this problem by cutting longitudinal slits through the entire magnetron anode system. With such slits, the magnetic field penetration is not restricted by the diffusion rate. Thus, one can apply a microsecond-timescale magnetic field produced by a solenoid powered by a considerably smaller power supply. We test this idea by using particle-in-cell (PIC) simulations of a magnetron for the axial output design suggested by Xu et al. (2018) fed by a split cathode (Leopold et al. , 2020). With a split cathode, the second major problem with relativistic magnetrons is alleviated—pulse shortening is avoided.

An effective design for cold cathode named as the interdigitated field electron emission driving-secondary electron emission (FEE-SEE) cathode is proposed in this article. The cathode consists of an FEE region and an SEE region, which integrates the advantages of the field emission and secondary emission on the M-type device. The excellent FEE performance of the directional single-wall carbon nanotubes (SWCNTs) with an effective method of directly imprinting the SWCNTs sludge on a substrate is studied for obtaining higher primary excitation current. Meanwhile, the cathode prebunch technique is implemented by imposing a fivefold azimuthal variation on the SEE cathode of a ten-cavity magnetron, which could prebunch the electrons into the desired mode at birth to enhance stability and speed startup time. A 3-D particle-in-cell simulation analysis is used to predict a novel cold cathode magnetron with high output power of 3144 W with 6.2% efficiency enhancement with reference to the conventional thermionic cathode applied to the 2450-MHz magnetron. Its startup time is about 100 ns with excellent stability and pure output spectrum.

The effect of magnetic field on plasma characteristics in a magnetron with a hollow cathode was carried out. The magnetic field in this device is of complex geometry, since it consists of many permanent magnets and an electromagnet. The calculated geometries of the magnetic field were used in experimental studies. Measurements have shown that the magnitude and geometry of the magnetic field have a strong effect on the plasma parameters.

A plastic plate made of polycarbonate (PC) was functionalized as a water-repellent nature by unbalanced radio-frequency(rf) magnetron plasma sputtering using polytetrafluoroethylene target. In order to build the unbalanced rf magnetron plasma, 3D magnetic field analysis is simulated at three setups using ferrite, samarium cobalt and neodymium magnets so that the combination of ferrite and neodymium magnets is selected. A thin film is prepared on the PC plate at argon gas pressures of 2 and 50 Pa and rf input powers of 50, 100, 150 and 200 W. The functionalized PC surface has resulted in hydrophobic nature, that is, a water contact angle is higher than 90 degree, at all experimental conditions. It is found that the water contact angle is independent with rf power at approximately 108 degree at low pressure of 2 Pa, whereas it gradually increases with increasing rf power from 104 to 112 degree at high pressure of 50 Pa. These surfaces were analyzed by X-ray photoelectron spectroscopy (XPS) analysis. The ratio of F 1 s component to all components of C 1 s, O 1 s and F 1 s from XPS spectra for 2 Pa was higher than that for 50 Pa.

The paper aims to obtain thin films of nickel and zinc through the magnetron-assisted spraying process and their characterization from a structural point of view, of electrical, optical properties and corrosion resistance. It was found that as the intensity and discharge power increase, changes occur in the structure and properties of the deposited films.

Most high-power gyrotrons are driven by the thermal cathodes, and the output power can only reach megawatt (MW) level. In the present study, a single anode explosive emission cathode (EEC) magnetron injection gun (MIG) with the high beam current, the pitch radio of 1.2 and the controlled beam velocity spread was designed. At the peak voltage of 300 kV, the peak beam current of 1.1 kA and pulsewidth of 170 ns were emitted by a carbon fiber array (CFA) emitter. Compared to the reported EEC MIG, large beam loss was avoided in this experiment. The guiding center radius of 14.1 mm was close to the simulation results. CFA has the stronger emission capability, the lower emission threshold electric field, and the better emission uniformity than sharpened edge graphite (SEG), so it is suggested as the emitter of the EEC MIG.

—The influence of the parameters of dc reaction magnetron sputtering of two monoelement targets (Ti, Pb) onto substrates made of a VT6 titanium alloy and 12Kh18N10T steel on the microhardness, the phase composition, and the texture of the sputtered composite coatings is studied. The coatings consist only of Pb and PbO at a lead cathode current of 0.2 A and also include TiN at a current of 0.1 A. The coatings on the VT6 alloy have a higher microhardness as compared to the coatings on 12Kh18N10T steel, which is due to the nitriding-assisted hardening of titanium substrate. The following correlation of the texture with the microhardness is found: the (111) pole density increases threefold and the microhardness of coatings decreases sharply when the ratio of the argon and nitrogen flow rates increases from 2.08 to 4.3.

Tools coated CrN based alloys are currently used in several industries for machining and manufacturing, but present severe wear, limiting their service life. Seeking an alternative, three CrMoN monolayers (~1µm in thickness) coatings with varying in the Mo percentage content were elaborated using the RF magnetron co-sputtering method. These coatings were evaluated and compared with the alloy currently used (CrN) by electrochemical tests in NaCl solution (stationary and no stationary method) and sliding wear tests (ball-on-disc configuration) performed at room temperature. The results indicate that the samples coated with CrMoN presented better performance against wear and corrosion than the uncoated sample. Among the coatings, the labeled C1 (27 % Mo) showed the best corrosion resistance as it presents a positive corrosion potential Ecorr. However, the best wear resistance (lowest coefficient of friction) was shown by coating labeled C4 (33 % Mo). All of the tested specimens underwent abrasive wear in addition to adhesive wear.

Magnetron is an important microwave device because of its advantages of high power, small size, lightweight, and low cost. However, due to the instability of magnetron spectrum, it is difficult to use magnetron when we need high-stability spectrum. In order to improve the output spectrum of the magnetron, many efforts have been made and we find that the ripple of magnetron power supply has a great influence on the spectrum. So this article studies this influence systematically. First, we start from the equivalent circuit of magnetron, from which we can derive the equation of high-voltage power supply ripple and magnetron’s time-domain output. Then we obtain the relationship between power supply ripple and magnetron’s frequency-domain output spectrum by fast Fourier transform. Through theoretical derivation, numerical simulation analysis and experiment, we find that with the increase of ripple, the spectrum is gradually disordered, noise frequency point appears, center frequency point remains unchanged, and output energy reduces. The research results of this article provide theoretical guidance for the realization of high-stability spectrum magnetron.

Using the reactive DC magnetron sputtering of two separate single-element Ti and Pb targets, a TiN–Pb composite coating was deposited onto a substrate made of VT6 titanium alloy. The studies are carried out on currents on the Pb cathode of 0.2 and 0.1 A and two fixed values of the argon flow rate of 6.0 or 8.5 cm3/min, as well as the flow rate of nitrogen supplied to the chamber varying from experiment to experiment. The composition of the coatings is determined by energy dispersive analysis. It is shown that the amount of lead in the coatings ranges from 0.5 to 16%, depending on the current on the Pb cathode and reactive gas consumption N. The microhardness and wear of the coatings are determined for each deposition mode. Depending on the ratio of argon and nitrogen fluxes, the thickness of the coatings varies from 1.9 to 5.2 μm. The effect of the deposition parameters of magnetron TiN–Pb coatings on the structure and phase composition is investigated by the X-ray diffraction method. It is shown that, at a current value of 0.2 on the Pb cathode, the coating consists of Pb and PbO and, at a current of 0.1 A, it consists of TiN, Pb, and PbO, while an increase in the ratio of argon and nitrogen fluxes leads to an increase in the fraction of TiN, the intensity of surface saturation, titanium substrate with nitrogen, microhardness, and wear resistance. Under all deposition conditions, the TiN coating is characterized by a typical texture (111), the intensity of which varies nonmonotonically.

Plasmonic nanocomposite thin films find exciting applications in environmental remediation and photovoltaics. We report on thermal annealing driven development of morphology, structure and photocatalytic performance of Au–Cu2O–CuO nanocomposite thin film. Nanocomposite thin film coatings of Au–Cu2O–CuO, prepared by radio frequency (RF) magnetron co-sputtering, were annealed at different temperatures. Thermal annealing driven evolution of morphology of Au–Cu2O–CuO nanocomposite was studied by field emission scanning electron microscopy (FESEM), which revealed significant growth in size of nanostructures from 10 nm to 69 nm upon annealing. X-ray diffraction (XRD) together with Raman studies confirmed the nanocomposite nature of Au–Cu2O–CuO film. UV-visible diffuse reflectance spectroscopy (UV-vis-DRS) studies showed band gap variation from 2.44 eV to 1.8 eV upon annealing at 250 °C. Nanocomposite thin film annealed at 250 °C exhibited superior photocatalytic activity for organic pollutants [methylene blue (MB) and methyl orange (MO)] decomposition. The origins of thermal transformation of morphological, optical and photocatalytic behaviour of the Au–Cu2O–CuO nanocomposite coating are discussed.

Refractory high-entropy alloys (HEAs) possess many useful properties such as high strength and high-temperature stability. So far, most studies on refractory HEAs have been limited to a few well-known compositions and on their coarse-grain bulk forms. Here we fabricate nanocrystalline (TiZrHf)x(NbTa)1−x HEA thin films with a large range of compositions (x = 0.07–0.90) by the direct current (DC) magnetron co-sputtering technique and measure their mechanical properties using the nanoindentation method. All the as-deposited HEA thin films show a solid-solution body-centered cubic (bcc) structure. As the compositional ratio (x) increases, the elastic modulus decreases from 153 to 123 GPa, following the trend of the rule of mixture. As x increases, the hardness first decreases from 6.5 GPa (x = 0.07) to the lowest value (4.6 GPa, x = 0.48) and then increases to the highest value (7.1 GPa, x = 0.90), showing a concave trend. The change in hardness might be attributed to the combinational influence caused by the atomic size and modulus effects, as well as the texture effect. The authors also propose a few open questions for future studies on this and related HEA systems.

Li7La3Zr2O12(LLZO)-based ceramics as promising solid-state electrolytes (SSEs) have received much attention for use in high-energy lithium (Li) metal batteries. However, the Li growth through the solid garnet electrolyte under a low current density hinders its practical application. In this work, the Cu doped Li3Zn was designed to guide uniform Li deposition by magnetron cosputtering and an in situ alloying reaction on Li6.5La3Zr1.5Ta0.5O12 (LLZTO) pellets. After introducing the composite layer, a small interfacial area specific resistance (∼30 Ω·cm2) can be obtained. Improved lithium plating/stripping performance, including a long-life span of 450 h (under a current density of 0.8 mA cm-2 without short circuit) and a high critical current density (CCD) of 2.8 mA cm-2 is performed by the composite interlayer with a Zn:Cu ratio of 10:1. And the Li/Cu-Li3Zn SSEs/LFP full cell exhibits good electrochemical performance. Accordingly, the Li deposited behavior in the Li plating/stripping process at the intermediate layer is discussed in detail. This work provides a new sight for the alloy interface designed on the solid-state garnet SSEs for high performance lithium metal batteries under high current density.

The investigations of (Ti + Al)-SiO2 surfacing by magnetron deposition are presented in this article. The correlation between film`s thickness deposited on the particles by mechanocomposites and magnetron sputtering time was established. It was determined that the rational time for surfacing by Ti-Al mechanocomposites system is about 40 minutes. According that deposition time the thickness of deposited SiO2 films were obtained as 5.2 microns.

The development of modern technologies in various industries cannot be imagined without the development and use of new materials, including new highly entropic alloys (HEA) and coatings based on them, as more advanced in terms of performance compared to traditional materials and coatings. Methods for producing various highly entropic alloys are described in many literature. Almost all such technologies at the moment cannot be applicable in the mass production of parts due to the high cost and lack of appropriate infrastructure and production technologies. However, obtaining coatings formed on the basis of highly entropic alloys for various parts of mechanisms and machines is currently a highly promising direction in improving the operational properties of work surfaces. The goal of this work is to create highly entropic coatings obtained by magnetron sputtering of special multicomponent targets. The paper shows the possibility of synthesis of coatings of the predicted composition and properties. A coating based on a matrix target made of 12Kh18N10T steel with pressed multicomponent Cr-Ni-Zr-Ti-Cu pellets was synthesized. The elemental composition of the coating and its properties were determined, the microhardness was measured, and the functional properties were established.

DC reactive magnetron sputtering of two separate single-element Ti and Pb targets was used to deposit a TiN–Pb composite coating onto a substrate made of the VT6 titanium alloy. The studies were carried out at Pb cathode currents of 0.2 and 0.1 A and two fixed argon flow rate values of 6.0 or 8.5 cm3/min, and the flow rate of nitrogen supplied to the chamber varying from experiment to experiment. The composition of coatings was determined by energy dispersive analysis. It was shown that the amount of lead in the coatings ranged from 0.5 to 16 wt.% depending on the Pb cathode current and reactive nitrogen consumption. Coating microhardness and wear were determined for each deposition mode. It was found that coating thicknesses varied from 1.9 to 5.2 μm depending on the ratio of argon and nitrogen fluxes. The effect of TiN–Pb magnetron coating deposition parameters on the structure and phase composition was investigated by X-ray diffraction method. It was shown that the coating consists of Pb and PbO at the Pb cathode current of 0.2 A, and of TiN, Pb, and PbO at the current of 0.1 A, while an increase in the ratio of argon and nitrogen fluxes leads to an increase in the fraction of TiN, the intensity of titanium substrate surface saturation with nitrogen, as well as microhardness and wear resistance. Under all deposition conditions the TiN coating features by a typical texture (111), the intensity of which varies nonmonotonically.

Herein, Ag–Mo films were deposited on Si(100) substrates by magnetron co-sputtering. The phase evolution and microstructural investigation revealed that the pure Ag phase and no Ag(Mo) solid soluti...

The technological process of thin-film sputtering significantly depends on the quality of the target for magnetron sputtering. This paper presents the features of obtaining the multicomponent magnetron target for the formation of non-porous transformation-hardenable coatings by the method of impact electric pulse consolidation. Special considerartion is given to the blend preparation and technological parameters of compaction. Blend powder consolidation under impact electric pulse compaction at different speeds of the striker has been investigated. At high speeds of the drop-hammer striker, the time parameters of the dynamic impact and electric pulse heating of the powder billet are shown to superpose, which leads to the final consolidation of the ceramic blend of the target for magnetron sputtering. The use of the technology of impact electric pulse compaction has made it possible to obtain multicomponent magnetron targets for formation of non-porous transformation-hardenable coatings of a given composition.

The analysis of tribotechnical parameters of interfaces with solid lubricating coatings based on MoS2, applied by different methods, was carried out according to the results of tests in vacuum. The surface friction temperature is calculated on the basis of the performed assessment of the load-speed characteristics of these interfaces. Based on the results of tribovacuum tests, the thermocorrelation dependence of the resource of a friction pair with solid lubricating coatings MoS2, applied by vacuum (magnetron and high-frequency) and suspension methods, on the surface friction temperature of the interface was determined. On the basis of this dependence, a method for calculating the resource of the studied tribointerfaces is proposed.

Element doping into the Cu2ZnSn(S,Se)4 (CZTSSe) absorber is an effective method to optimize the performance of thin film solar cells. In this study, the Cu2InxZn1-xSn(S,Se)4 (CIZTSSe) precursor film was deposited by magnetron cosputtering technique using indium (In) and quaternary Cu2ZnSnS4 (CZTS) as targets. Meanwhile, the In content was controlled using the direct current (DC) power on In target (PIn). A single kesterite CIZTSSe alloy was formed by successfully doping a small number of In3+ into the main lattice of CZTSSe. The partial Zn2+ cations were substituted by In3+ ions, resulting in improving properties of CZTSSe films. Morphological analysis showed that large grain CIZTSSe films could be obtained by doping In. The well-distributed, smooth, and dense film was obtained when the PIn was 30 W. The band gap of CIZTSSe could be continuously adjusted from 1.27 to 1.05 eV as PIn increased from 0 to 40 W. In addition, the CIZTSSe alloy thin film at PIn = 30 W exhibited the best p-type conductivity with Hall mobility of 6.87 cm2V−1s−1, which is a potential material as the absorption layer of high-performance solar cells.

An effective method of tuning the frequency of magnetron is studied in this article. The frequency-agile technique is based on changing the structure of the resonator by tuning elements. First, the working principle of this frequency-agile technique for changing an anode structure is proposed and simulation analysis suggested the good performance of this device. Next, a 3-D particle-in-cell simulation analysis is implemented to predict a frequency-adjustable magnetron with an output power of 2 kW, a mode separation of 50%, an efficiency of 67.7%, a bandwidth of 65 MHz, and a sinusoidal modulated signal. It was found in an experiment that our proposed prototype magnetron has a tunable bandwidth which meets with the simulation results. This effective method has a great potential for application in the frequency-agile magnetron.

In this study, the oxygen scavenger layer (OSL) is proposed as a back channel in the bilayer channel to enhance both the electrical characteristics and stability of an amorphous indium-gallium-zinc oxide thin-film transistor (a-IGZO TFT) and also to enable its fabrication at low temperature. The OSL is a hafnium (Hf)-doped a-IGZO channel layer deposited by radio-frequency magnetron cosputtering. Amorphous IGZO TFTs with the OSL, even if annealed at a low temperature (200 °C), exhibited improved electrical characteristics and stability under positive bias temperature stress (PBTS) compared to those without the OSL, specifically in terms of field-effect mobility (31.08 vs 9.25 cm2/V s), on/off current ratio (1.73 × 1010 vs 8.68 × 108), and subthreshold swing (0.32 vs 0.43 V/decade). The threshold voltage shift under PBTS at 50 °C for 10,000 s decreased from 9.22 to 2.31 V. These enhancements are attributed to Hf in the OSL, which absorbs oxygen ions from the a-IGZO front channel near the interface between a-IGZO and the OSL.

We propose a facile and combined methodology to develop magnetron sputtered various metals and alloy (e.g. tungsten, tin and nichrome), and metal oxide (indium tin oxide) thin film-based micro-patt...

A further increase in the efficiency of low-temperature plasma modification of the metal product surface layer is possible on the basis of the process supervision. The article presents an approach and a developed model that allows to receive and study the behavior of signals arising in the electrical circuit of a technological unit under the interaction of electromagnetic and electrostatic fields that form a low-temperature plasma gas discharge near the product surface. Data confirming the v alidity of the model are presented. The analysis of electrical signals is carried out. The indicator reflecting the stability of the process of plasma interaction with the product surface by the degree of the signal form deviation from the sine curve is substantiated. The study of the possibility to control the modification process was carried out. The dependences of the stability index on the product parameter values as functions of the process operating parameters — bias potential or magnetron anode current — were obtained and studied. The reliability of the theoretical studies results was experimentally confirmed, which showed that the composite structure synthesis process remains the most stable with a smooth decrease in the bias potential, as well as a smooth and abrupt increase in the magnetron anode current.

The results of the study on the formation of electron beams by the magnetron gun at various configurations of the magnetic field in the beam transport channel are presented. A technique for modeling the processes of formation of electron flows and control of the distribution of beams by collimation is presented. Numerical simulation of the dynamics of electron beams in the magnetic field of the gun for its various configurations has been carried out. Experimental data on the transportation and collimation of electron beams are presented. The possibility of stable formation of an electron beam in the axial direction during its transportation is shown. Imprints of the collimated electron beam were obtained on metal targets. The possibility of controlling the beam diameter by varying the magnetic field is shown. Comparison of the results of numerical modeling and experimental data on the motion and collimation of the tubular electron flow is carried out.

Tantalum (Ta) and titanium (Ti) metal targets were direct current (DC) magnetron sputtered in the oxygen environment by varying its relative areas to deposit (Ta2O5)1-x- (TiO2)x (TTOx) thin films, with x = 0, 0.03, 0.06, and 0.08, onto the boron-doped p-silicon (1 0 0) and optically polished quartz substrates, at room temperature; and were annealed at 500, 600, 700, and 800 °C, for 1.5 h. The thin films annealed at and above 600 °C show the Ta2O5 structure. The leakage current density and capacitance-voltage (C–V) characteristics were measured for TTOx, x ≤ 0.08, assisted Ag/TTOx/p-Si metal– oxide– semiconductor (MOS) structures. The leakage current density was found minimum, for the films annealed at 800 °C, for all the prepared TTOx films, x ≤ 0.08. The minimum leakage current density 1.6 × 10−8 A/cm2, at 3.5 × 105 V/cm electric field, was observed for x = 0.03, annealed at 800 °C, among the prepared compositions. The prepared TTO0.03 films, annealed at 700 °C show maximum dielectric constant 39, at 1 MHz. The optical parameters, viz., refractive index (n), extinction coefficient (k), and optical band gap (Eg) of the films, with x = 0.03, prepared on quartz substrates, were determined from their optical transmittance plots. The values of n and k of the crystalline films were observed increasing from 2.123 to 2.143, and 0.099 to 0.130, respectively, at 550 nm wavelength; and Eg decreasing from 3.95 to 3.89 eV with the increasing annealing temperature, from 600 to 800 °C. Ohmic emission, in the lower electric field; Schottky and space-charge- limited current conduction mechanisms, in the intermediate to higher electric fields, were generally envisaged from the current-voltage characteristics in the prepared Ag/TTO0.03/p-Si structures.

A high-throughput method was applied to study oxidation behavior of Nb–Si based alloy using composition spread alloy film as combinatorial libraries. An extended range of composition gradients of Nb–Si based alloy film was deposited by (multi)magnetron co-sputtering. The as-deposited film was composed of amorphous phase. Cr2Nb, Nb5Si3 and Nbss could be detected after annealing treatment. After oxidation at 1250 ​°C for 10 ​min and 20 ​min, the film composition space was divided into three regions of the distinct oxide scales. The compositions for establishment of the different oxides on Nb–Si based alloy was defined efficiently across the entire composition space by the combinatorial libraries.

Were produced TiO2 thin coatings prepared, on substrates pure Titanium using a deposition by magnetron sputtering technique, the percentage of oxygen was varied, to study the behavior in terms of friction coefficient corrosive fluids such as those related to the human body. Electrochemical Impedance Spectroscopy (EIS), wear tests with a tribometer, were performed to obtain the tribo-corrosion mechanism of deterioration, taking into account the dual corrosion wear system. The phases were identified by X-ray Photoelectron Spectroscopy (XPS) high resolution. It is determined through the tests performed that the surface treatment has a different effect for each percentage of oxygen influenced by the simulated body environments. The wear performance analysis indicated that the TiO2 film's protection had increased as the percentage of oxygen in the gas mixture (Ar/O2) varied and other synthesis parameters such as deposition time, target power, and substrate temperature remained constant.

Great progress has been made on machine learning and its applications are expanding rapidly nowadays. Through the case study of optimizing a magnetron injection gun for gyrotron devices, the functions of machine learning were investigated by using two supervised learning algorithms, regression trees and artificial neural networks. They showed excellent performance in predicting the outputs, exploring the importance of the input parameters and the relationship with the output parameters. Machine learning can be a useful tool in the development of microwave vacuum electron devices.

Purpose The purpose of this paper is to compare the electrical conductivity and tribological properties of magnetron sputtered silver (Ag), copper (Cu) and aluminum (Al) thin films under conductive grease lubrication. Design/methodology/approach Three types of silver (Ag), copper (Cu) and aluminum (Al) thin films were prepared by magnetron sputtering. Current-carrying friction tests were carried out by a ball-on-plate reciprocating friction and wear tester. Scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDX) were used to observe and analyze the worn surface and cross-section morphology of the films. Findings Silver and Cu films exhibited good conductivity and tribological properties, which were mainly attributed to the synergy of the protective tribofilm generated by conductive grease, current-induced thermal effect and magnetron sputtered films effect. Al film was worn through. Large pitting storing lubricate were only found in Ag film. Cu film showed a similar surface uniformity with Ag film. Originality/value This study provides a reference for the design and application of conductive grease and investigates the current-carrying friction behaviors of magnetron sputtered films as electrical contact materials. The comparison of current-carrying friction behaviors of the three films was rarely covered in previous studies.

This article presents the electromagnetic and particle-in-cell (PIC) simulation results of an X-band coaxial magnetron obtained using commercially available 3-D simulation tools CST particle studio. The operating frequency of the magnetron is 9.5 GHz with the tuning range of 8.5–9.5 GHz and the output power of 200 kW. It is observed by simulation that stable operation is not possible without eliminating the spurious cavity modes. For this purpose, the inner wall of the anode block has been loaded with the lossy dielectric material in the form of an annular cylinder having dielectric permittivity 23 and loss tangent 0.24. When the anode wall is loaded with lossy dielectric material, eight space charge spokes are observed during the stable operation of the magnetron which correspond to $\pi $ -mode of operation in a coaxial magnetron having 16 vanes. A clear oscillation spectrum with a single peak is observed at 9.350 GHz with no other noticeable peaks. The radiated output power obtained in simulations is about 235 kW, with an anode voltage of 23 kV and an anode current of 30 A. The applied external magnetic field is 0.36 T and the corresponding efficiency of the magnetron operation is ~34%. The frequency tunability of the magnetron and the effect of frequency variation on the output power of the magnetron have also been studied by varying the length of the outer coaxial cavity. The frequency has been varied from 8.65 to 9.577 GHz and the corresponding variation in the output power is about 16%.

A pulsed magnetron system that generates high-energy microwave pulses at a frequency of 100 Hz and an average power of 5 kW is described. A magnetron current pulse is generated using a circuit with 16 identical transistor units with an operating voltage of 800 V, which are connected in series to the primary winding of a high-voltage pulsed transformer with a transformation ratio of 5 during the pulse interval. Thus, a voltage pulse with an amplitude of up to 65 kV, a current of 140 A, and an adjustable duration of 1–6 μs is formed. The experimental data on the operation of the system for a pulsed microwave magnetron and an equivalent load are presented.

A method for measuring the relative amount of gas released from the magnetron during its vacuum pumping is presented. Equations describing three main reactions during pumping are obtained. The developed method is tested on model objects and used to measure the relative amount of gas released from a serial magnetron during vacuum pumping. The efficiency of pumping out the magnetron is analyzed for various methods of degassing. A method is proposed for accelerating desorption-diffusion processes when the magnetron body is treated with ultrasonic vibrations simultaneously with its heating during vacuum pumping, which increases the gas release efficiency more than twofold.

One of the parameters that has the most influence in the uniformity of microwave heat processing is frequency. Unlike the traditional magnetron microwave system, it is possible to control and set up the frequency with the newly developed solid-state microwave system. The aim of this study was an investigation of the effect of fixed frequencies and frequency sweep loops (in the range of 2400–2500 MHz) on the uniformity of heat processing in circular gellan gel model samples containing Maillard reactive agents in a solid-state microwave system. Therefore, the purpose was to compare the solid-state system at fixed frequencies in which the megaton generator also works. While the magneton generator runs at random frequencies within a certain range, solid-state systems are capable of conducting heat processing at fixed frequencies. This novel characteristic will be evaluated through the implementation of different trials at various fixed frequencies. Additionally, the effect of changing frequencies is evaluated through frequency sweep loops, where the frequency of the solid-state system is changed in a pre-determined pattern. The results obtained from the time-temperature indicator of the Maillard reaction and the temperature indicator of infrared thermography showed that the heat processing of samples with the frequency sweep loops, even without turntable rotation, can be more uniform in comparison to those with fixed frequencies and turntable rotation. Moreover, the frequency sweep loops not only improved the uniformity of temperature distribution of the heated sample, but also increased the average temperature of processed samples and, thus, microwave heating absorption.

(Ta2O5)1-x- (TiO2)x (TTOx) thin films, with x = 0, 0.03, 0.06, 0.08, and 0.11, were deposited using magnetron direct current (DC) sputtering method onto the P/boron-silicon (1 0 0) substrates by varying areas of Tantalum and Titanium metallic targets, in oxygen environment at ambient temperature. The as-deposited thin films were annealed at temperatures ranging from 500 to 800 °C. Generally, the formation of the Ta2O5 structure was observed from the X-ray diffraction measurements of the annealed films. The capacitance of prepared metal– oxide– semiconductor (MOS) structures of Ag/TTOx/p-Si was measured at 1 MHz. The dielectric constant of the deposited films was observed altering with varying composition and annealing temperature, showing the highest value 71, at 1 MHz, for the TTOx films, x = 0.06, annealed at 700 °C. With increasing annealing temperature, from 700 to 800 °C, the leakage current density was observed, generally decreasing, from 10−5 to 10−8 A cm−2, for the prepared compositions. Among the prepared compositions, films with x = 0.06, annealed at 800 °C, having the observed value of dielectric constant 48, at 1 MHz; and the leakage current density 2.7 × 10−8 A cm−2, at the electric field of 3.5 × 105 V cm−1, show preferred potential as a dielectric for high-density silicon memory devices.