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We have developed a solid electrolyte ion source (SEIS) with CsAg4Br2.68I2.32 film deposited on a silver tip. In the paper, Ag+ ion emission was significantly enhanced and the ion current of 1.6 μA was obtained at 168 °C temperature and 20 kV accelerating voltage. I-T and I-U characteristics were well described by the field evaporation (FEV) model, and the surface potential barrier was estimated to be 0.19 eV. Experimental investigations of the Ag+ ion emission mechanisms revealed that the solid electrolyte film plays an important role of ion-transport system, and the emitted Ag+ ions were compensated by the ions diffusing from the silver reservoir (Ag-tip). The developed SEIS was exploited for the synthesis of Ag nanoparticles on Si surface. The average size of these nanoparticles was estimated 15.5 ± 0.3 nm, and the projected range Rp of the low-energy high-dose Ag+ ions implanted Si sample was found to be less than 5 nm using TOF-SIMS depth profiling. The future application of SEISs in ion propulsion systems of miniature spacecraft with limited on-board payloads was discussed, and the thrust was estimated within μN range.

Funding Information: This work was supported by the Ministry of Education and Science of the Russian Federation in the frame of the state assignment FSSN-2020-0003. Publisher Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. The performance characteristics (microhardness, porosity, roughness, and transient resistance) of Au–Ru coatings with and without the Co–W alloy barrier sublayer electrodeposited on the surface of contact blades of commercially produced reed switches were investigated. It was found that the barrier sublayer reduces the average roughness of the coatings without significant change in their porosity. The Au–Ru coatings without sublayer exhibited a greater variation in the transient resistance during an increase in the pressing force. The service time of reed switches with the barrier sublayer increased in both testing modes: in low-power (50 mV, 5 µA, 50 Hz) by more than 4 × 106 switching cycles, and in mean-power (12 V, 0.25 A, 50 Hz) by more than 1.8 × 106 switching cycles. publishersversion published

Time-of-flight secondary ion mass spectrometry has been used for depth profiling of 530 nm-thick Be/Al-based multilayer interferential structures fabricated by magnetron sputtering for X-ray radiation at the wavelength of 17.1–17.5 nm. The introduction of ultra-thin (

An analytical review of the modern state of the development of ion sources with solid electrolytes (superionic conductors) for the aerospace and ion-beam technologies is presented. The methods for synthesis and properties of solid electrolytes, the formation of mobile ions at the “reservoir–electrolyte” interface, the fast-ion transport in a thin electrolyte film under the action of an external electric field, and the processes of ion emission (evaporation) from the surface of the electrolyte into a vacuum at a temperature below the thermionic-emission threshold and an electric-field strength that is lower than that of field-ion emitters are discussed. The operation modes, the design and manufacturing technology of anion and cation sources are described in detail. Methods for improving the performance and the main fields of application, including electrostatic rocket engines (ion microthrusters), for which a matrix solid-state ion–electron source was designed and patented, are analyzed.

A point-like silver ion source with thin film of RbAg 4 I 5 solid electrolyte was developed for application in field emission electric propulsion systems. The solid electrolyte produced by mechano-chemical synthesis was deposited on the apex of a silver tip using pulsed laser deposition. The running tests at 195 °C working temperature and 10 kV accelerating potential have demonstrated that the source can continuously produce positive ion current of several hundred pA during a few days with a peak value of 25–50 nA. Using TOF-SIMS analysis it has been shown that the ion current consists of Ag + with a small contribution of Rb + , lower than 0.5 at.%. We suggest that Ag + emission occurs mainly by means of field-assisted ion evaporation and/or ion desorption, and the solid electrolyte plays a role of the transport system, in which the emitted Ag + ions are continually replaced by mobile Ag + ions delivered from the silver reservoir by direct mass transfer under the influence of an external electric field.

Using mass-resolved ion scattering spectrometry, spectra of Ne+ ions scattered at an angle of 120° from the surface of GaP in the energy range of 0.4–1.96 keV have been studied in detail. In the spectra, in addition to the peaks of elastic binary Ne+/P and Ne+/Ga collisions, the peak of sputtered neon ions has been found, as well as the wide peak (a “hump”), the energy of which slightly depends on the energy of primary ions and the intensity considerably increases with an increase in this energy. In our opinion, the main contribution to this peak is made by neon ions that undergo multiple collisions with gallium and phosphorus atoms on the surface and deeper layers of the sample and keep their charge due to reionization processes.

The paper presents the research results of formation peculiarities of barrier electrically insulated coatings based on titanium oxide (TiO2) under conditions of AC-DC electrochemical anodizing. It is shown that overlapping of AC component (at the frequency of 100 kHz – 10 MHz) leads to formation of coatings 1.2–1.4 times thicker. Dependences of the coating thickness on frequency under various ratios of the AC-component amplitude to the DC-component of anodizing voltage have been obtained.

The paper presents the research results of influence of various parameters of magnetic field concentrator geometry on sensitivity of magnetically controlled MEMS switches. It is shown that magnetic sensitivity increases with the growth of the magnetic concentrator width and practically does not depend on its length. It is established that dependence of magnetic sensitivity on the overlap length of the ferromagnetic flexible contact-concentrator has a minimum corresponding to 2-3 lengths of the contact gap. Recommendations on sensitivity increase of magnetically controlled MEMS switches are provided.

The present paper has suggested a new non-observational method to calculate electronic structure of carbynes taking into consideration the influence of the spin-orbital coupling. The method is demonstrated by calculations of the structure splitting at the Fermi level in cumulene and polyyne carbynes having semiconductor and metallic electronic structure correspondingly. These couplings result in 2 - 3 meV gaps.

The present paper contains results of the experimental researches of structure properties of the catalytic coating based on the nanoporous TiO2 film affected by corona-discharge plasma in air atmosphere under atmospheric pressure in the test system of needle-plane electrodes. Coating of the plate electrode was found to influence insignificantly on the discharge current-voltage characteristic, however if there is a coating on the plane electrode surface, an offset is observed towards lower currents under constant voltage at the gap. Obtained data on the surface morphology change shows that under negative corona erosion of the nanoporous TiO2 coating surface is practically absent and under positive corona, decrease of the coating thickness is observed.

Ar2900 clusters with energy in the range of 10.4–69 keV were used to bombard the surface of pressed Si nanopowder targets. High nonmonotonic sputtering yield is observed within the energy range of 10.4–34.5 keV, which is considered as enhanced by the finite size effect of the target particles. The cluster bombardment results in the sputtering of Si nanoparticles with a mean size of ca. 12 nm. The number of the sputtered nanoparticles is correlated with the sputtering yield within the energy range of 10.4–34.5 keV. Hence, their formation is associated with the finite size effect. Scanning electron microscopy revealed the formation of debris on the target surface starting at the cluster energy of 15.3 keV, which results in reducing the finite size effect and consequently the sputtering yield. Individual impacts of the argon clusters are observed as craters of 3–6 nm in diameter on the Si particles surface. The crater formation is considered to be responsible for the sputtering at the cluster energy in the range of 15.3–69 keV.

Quantification of Ge in Si1–xGex structures (0.092 ≤ x ≤ 0.78) was carried out by time-of-flight secondary ion mass spectrometry (TOF-SIMS) and electron-gas secondary neutral mass spectrometry (SNMS). A good linear correlation (R2 > 0.9997) of the intensity ratios of secondary ions GeCs2+/SiCs2+ and 74Ge−/30Si− and post-ionized sputtered neutrals 70Ge+/28Si+ with Ge concentration was obtained. The calibration data were used for quantitative depth profiling of [10 × (12.3 nm Si0.63Ge0.37/34 nm Si)] structures on Si. Satisfactory compliance of the quantified Ge concentration in SiGe layers with the values obtained by high-resolution X-ray diffraction was revealed for both techniques. SIMS and SNMS experimental profiles were fitted using Hofmann's mixing-roughness-information depth (MRI) model. In the case of TOF-SIMS, the quality of the reconstruction was better than for SNMS since not only the progressing roughening, but also the crater effect and other processes unaccounted in the MRI simulation could have a significant impact on plasma sputter depth profiling.

The main features of electrochemical deposition of coatings based on Ni&ndash, W binary alloy in the pulse current mode using pyrophosphate electrolytes were studied. Two electrolytes with a pH of 8.7 and 9.5 were used. The deposition was carried out with the current density varying in the range of 0.01&ndash, 0.1 A&middot, cm&minus, 2, and the duty cycle (the relative pulse duration) was changed within the range 20&ndash, 100%. The surface morphology and elemental and phase composition of the coatings were studied by scanning electron microscopy, energy-dispersive X-ray microanalysis and X-ray diffractometry. The experimental conditions allowing us to achieve the maximum Faradaic efficiency and W content in the coatings were determined. It was found that the pulse current mode enabled the fabrication of crack-free coatings with a thickness greater than 6 &mu, m.

The paper contains results of researches on switching properties of contact coatings based on nanoscale ruthenium films obtained by the electrochemical deposition method. Dependences of contact resistance changes on a number of switching cycles under various thicknesses and roughness of the coating have been determined. The experiment results have determined optimal parameters of the contact coating necessary for provision of a minimal value of the MEMS-switch contact resistance in the steady mode.

The paper presents the results of numerical modeling of thermomechanical stresses and thermal fields for conditions of erosion-resistant electrode coatings of magnetically controlled MEMS switches with W-Ti-Cu structure at local temperature and electric current influence in axially symmetrical approximation. It is shown that the introduction of titan interlayer (30-100 nm) in the coating with W-Ti-Cu structure results in considerable (more than two times) decrease of internal thermomechanical stresses between layers that increases coating resistance to delamination. It is established that there is an optimum value of Ti layer thickness at which the minimum thermomechanical stresses are provided.

The paper presents complex research of the structure and electrophysical properties of thin films on the basis of Cr2O3, V2O5 and SiO2 oxides compounds. The paper studies binary compounds films of Cr2O3 -V2O5 and Cr2O3 - V2O5 -SiO2 films. The method of electron-beam evaporation is used for the films deposition; glass is used as the substrate. The films structure is studied by the methods of slow electron diffraction, infrared spectroscopy, and electron paramagnetic resonance. The films composition is determined by the X-ray microanalysis.In the course of studies the following regularities have been established:- dependence of the films structure on their composition;- dependence of electrophysical films properties on the their composition;- dependence of volt-ampere characteristics on the films composition (memory effect);- high film stability to the effect of electron flow and radiation in the discharge plasma.