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Although the control of bond structure and optical properties in hydrogenated amorphous germanium carbonitride films (a-GeC1−xNx:H) is important for technological applications, the composition dependence of chemical bonds, especially hydrogen-containing bonds, is not yet well explored. The evolution in refractive index (n) and Urbach tail width (E0) remains unclear. Here, we show that nitrogen content...
In this paper we investigated the annealing behavior of Ag nanoparticles in silica with and without defects. Silica samples with and without Ar ion pre-irradiation were implanted with Ag ions and then annealed at temperature from 300 to 850 °C. UV-VIS spectroscopy and TEM were used to characterize the optical absorbance property and size distribution of Ag nanoparticles, respectively. Optical absorbance...
Molecular dynamics simulations of Al1-xSixN samples with different Si content were carried out to investigate their structures, void distributions and mechanical properties. Such effects on other microscopic characteristics, such as bond-length distance, bond-angle and coordination number distribution have been observed. Based on the common neighbor analysis, we found that Si3N4 sample has amorphous...
Computational fluid dynamics (CFD) simulation for the sharp-edged nozzle was made using the OpenFOAM source code. Jet dynamics characteristics for the gas stream from a sharped-edged nozzle are then simulated under two-dimensional and axisymmetric steady state condition. Gas and particle velocities in a jet are obtained under different input and boundary conditions to provide an insight into the jet...
In this study, nanostructured hardystonite (HT) and titania (TiO2)/hardystonite (HT) dual-layered coatings were deposited on biodegradable MgCaZn alloy via physical vapor deposition (PVD) combined with electrophoretic deposition (EPD). Although a single layer nano-HT coating can decrease the corrosion rate from 1.68 to 1.02 mm/year, due to the presence of porosities and microcracks, the nano-HT layer...
The structure of the surface and near-surface layers of titanium nickelide (NiTi) single crystals having [111]В2 and [001]В2 orientation relative to the direction of Si-ion beam treatment was investigated. It was found that the orientation effects of selective sputtering and the channeling control the thickness of the oxide and amorphous layers, the depth of penetration of ions and impurities, the...
The direct simulation Monte Carlo method was used to study the rarefied gas flow through a cylindrical channel, taking into account heterogeneous reactions of dissociation-recombination on the surface. The main emphasis was placed on the study of the influence of heterogeneous processes on the degree of dissociation of the flow, coming out of the channel. The study was conducted for different relations...
We consider theoretically the electromagnetic radiation from a bunch of charged particles moving parallel or almost parallel to the surface of a solid, in conditions when the distance between the centre of the bunch and the surface is less than the transversal bunch size (beam brushes the surface). The radiation resulting proves to be a mixture of transition radiation and diffraction radiation. We...
This work presents the results of an investigation on the atomic hydrogen chemisorption of metallurgical graphene enhanced by plasma discharge at low pressures in the range of 5–20 Pa. It was experimentally revealed that hydrogenated graphene is not stable when in contact with humid oxygen or humid air. Moreover, thermal desorption experiments showed that hydrogen can be released from hydrogenated...
Experimental studies and computer simulations of inelastic interaction of low-energy Ar+ ions (100–2000 eV) with a ZrO2 surface are presented. The experiments were performed using Auger electron spectroscopy and secondary ion mass spectrometry. It has been found that the change of surface composition and the intensities of sputtered Zr+ and scattered Ar+ ions depend non-monotonically on the incident...
Electrical conductivity and Seebeck coefficient of nanostructured Ga added p-type CuSe thin films are investigated in the temperature range 6–300 K. The films prepared by vacuum co-evaporation method and characterized by various tools like X-ray diffraction, scanning electron microscopy and energy dispersive analysis of X-rays, for their structural, morphological and compositional studies, have agglomerated...
Due to the high speed and the high power density, the blade strength and the rotor overheating of a turbomolecular pump (TMP) are strongly related to the safety and the stability of the pump operation. For magnetically levitated TMPs, which can obtain an ultra-clean and ultra-high vacuum in comparison to traditional TMPs with oil-lubricated bearings, the rotor strength and overheating are limiting...
Low energy ion beam sputtering induced nanostructure formation on GaAs (001) surfaces at elevated temperature and at normal ion incidence has been studied for different ion energy and flux of the incident Ar+. Well-ordered nanoripples are found to develop, whose wave-vector is oriented along 〈110〉 crystallographic direction. The ripple structure is found to coarsen with ion energy, while it remains...
Unusually large normal grain growth rates and grain sizes were observed in Al films that were deposited from partially ionized vapor. The average grain size-to-thickness ratio ∼(8–25)h, where h is the film thickness, substantially exceeds those that were reported earlier for thin films and theoretically established limits. The materials thin film microstructure and surface morphology is being changed...
The Ce/Cr coating was deposited onto the surface of the open–cell NiCrFe alloy foam by the pack cementation. The effects of process parameters (Ce content and preparation temperature) on the microstructure and oxidation behavior of the Ce/Cr coatings were systematically investigated. Isothermal oxidation tests of Ce/Cr coatings with various Ce contents were performed at 1000 °C for 120 h, which were...
A model of the low-current (Townsend) discharge in argon–mercury mixture in the presence of a thin insulating oxide film on the cathode is developed. It takes into account the cathode ion-electron emission and the electron emission from the cathode metal substrate under the strong electric field generated in the film by the ion surface charge. An influence of the mixture temperature and the oxide...
Vacuum radio frequency (RF) plasma treatment was conducted on electropolished and passivated 316 LVM stainless steel (SS) surface by using Ar and O2. Contact angle measurements revealed that both Ar and O2 plasma treatments significantly increased the wettability of the SS surface by water. The physical and chemical effects induced by Ar and O2 plasma on SS were investigated via Atomic Force Microscopy...
Ti–50.3Ni (at%) alloy film was prepared by vacuum magnetron sputtering, followed by heat treatment at 460 °C for 40 min. The microstructure of the NiTi alloy film was studied using transmission electron microscopy. A nanoscale interwoven structure of B2 and R-phase was observed. The lattice correspondences between B2 and R-phase were analyzed using an electron diffraction pattern. The R-phase can...
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