scholarly journals Application of highly entropic coatings at simultaneous spraying of three cathodes in one cycle

2020 ◽  
Vol 97 (1) ◽  
pp. 7-17
Author(s):  
V.M. Yurov ◽  
◽  
S.A. Guchenko ◽  
E.N. Eremin ◽  
Keyword(s):  
Electron Microscope ◽  
Nanocrystalline Structure ◽  
Maximum Size ◽  
Columnar Structure ◽  
Sem Images ◽  
Grain Sizes ◽  
Erosion Coefficient ◽  
Ion Plasma ◽  
Antifriction Properties ◽  
Droplet Phase

In this work, we consider the application of highly entropic coatings while simultaneously sputtering three cathodes in a single cycle. The cathodes 12Cr15G9ND, Cu, Al were chosen as cathodes. The chemical composition of the cathodes was measured using a TESCAN MIRA 3 electron microscope. Using these cathodes, coatings were applied to polished samples of steel 45 in an NNV-6.6 I1 vacuum ion-plasma apparatus. The measurement was carried out using a MIRA 3 scanning electron microscope, an HVS-1000A microhardness tester, and a tribological research facility. SEM images show that with an increase of ×5000 or more, the droplet phase is clearly detected. The maximum size of the droplet phase reaches 12.0 μm with a variety of morphometric parameters varying, for example, in a geometry coefficient K from 0.8 to 1.0. Analysis of the coating at high magnifications (×7000 and ×20,000) without the droplet phase showed that the grain sizes of the coating are as follows: minimum — 0.23 microns, maximum — 0.65 microns (average of about 0.47 microns); while the coating structure is homogeneous. The analyzed type of structure refers to the zone of the so-called «competing texture», when a dense nanocrystalline structure is present in the lower region of the film, and a columnar structure is above it. The results of this study allow us to conclude that the simultaneous deposition of deposited cathodes of various metals (especially composite) in principle allows to obtain highly entropic coatings. Two points must be taken into account here: firstly, the number of atomized cathodes must be increased; secondly, it is necessary to take into account the values of the erosion coefficient for the cathodes used so that the atomized fluxes are equimolarly proportional. Measurements of coatings showed that the microhardness of Cu+Al+12Cr15G9ND is not inferior to ordinary steels, but of course it lags behind nanostructured coatings (30–50 GPa). The proposed coatings have antifriction properties of 3 or more times and can be used in tribological pairs.

scholarly journals Fabrication of Mesostructured Silica and Titania Rods on Substrates by Using Polycarbonate Membranes

2010 ◽  
Vol 2010 ◽  
pp. 1-4 ◽  
Author(s):  
Norihiro Suzuki ◽  
Yusuke Yamauchi
Keyword(s):  
Electron Microscope ◽  
Longitudinal Axis ◽  
Sem Images ◽  
One Pot ◽  
Polycarbonate Membrane ◽  
Entire Area ◽  
Transmission Electron ◽  
Polycarbonate Membranes ◽  
Fibrous Morphology ◽  
Oriented Parallel

By using the polycarbonate membrane a template, mesoporous silica rods are fabricated on a silicon substrate in one pot. From scanning electron microscope (SEM) images, the creation of fibrous morphology is confirmed over the entire area. The diameter of the obtained rods is consistent with that of the template. Transmission electron microscope (TEM) images revealed that the tubular mesochannels are uniaxially oriented parallel to the longitudinal axis of the silica rods. The mesoporous titania rods with anatase crystalline frameworks are also fabricated.

The Photoluminescence Enhancement and Stability of Porous Silicon by Cathodic Reduction and Acid Treatment

2014 ◽  
Vol 887-888 ◽  
pp. 458-461
Author(s):  
Chang Qing Li ◽  
Kun Wang ◽  
Pei Jia Liu ◽  
Qi Ming
Keyword(s):  
Electron Microscope ◽  
Porous Silicon ◽  
Acid Treatment ◽  
Cathodic Reduction ◽  
Luminescence Properties ◽  
Sem Images ◽  
Photoluminescence Enhancement ◽  
The Stability ◽  
Scanning Electron ◽  
Cathode Reduction

Porous silicon (PSi) was fabricated by using electrochemical anodic etching method. Then acid treatment and cathode reduction treatment were employed to improve the luminescence properties and stability of PSi material. Photoluminescence (PL) measurements and scanning electron microscope (SEM) were used to observe the luminescence properties and microstructure of samples, respectively. The results of PL measurements showed that the PL intensity and the stability of luminescence of samples after cathodic reduction and acid treatment were significantly improved. The SEM images showed that the porosity of PSi may be increased through the cathodic reduction treated.

The Energy Spectra of Secondary Electrons

2000 ◽  
Vol 6 (S2) ◽  
pp. 750-751
Author(s):  
David C Joy ◽  
David Braski
Keyword(s):  
Surface Layer ◽  
Electron Microscope ◽  
Secondary Electron ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Energy Spectra ◽  
Yield Coefficient ◽  
Sem Images ◽  
Secondary Electrons ◽  
Scanning Electron

It has been estimated that more than 90% of all scanning electron microscope (SEM) images ever published have been obtained using secondary electrons (SE) which are defined as being those electrons emitted with energies between 0 and 50eV. The properties of these secondary electron are therefore of considerable interest and importance. However, although secondary electrons have been intensively studied since their discovery by Starke in 1901 the majority of the work has been aimed at determining the SE yield coefficient and its variation with energy for elements and compounds. The energy spectrum of secondary electrons has received far less attention although it is evident that the form of the spectrum must have an effect on the image contrast observed in the SEM because SE detectors are energy selective devices. The few studies that have been made have mostly concentrated on spectra obtained from clean samples observed under ultra-high vacuum conditions. This is understandable, because it is certain that the presence of a surface layer of contamination will change the SE spectrum to some degree or other, but it is unfortunate because all specimens in real SEMs are dirty and it is information about this situation that is required.

The Photoluminescence Spectra Research of SiC Thin Film under Different Sputtering Powers

2019 ◽  
Vol 295 ◽  
pp. 93-97
Author(s):  
Chang Zhao ◽  
Man Zhao ◽  
Su Ye Lv ◽  
Qing Jun Liu ◽  
Guang Jian Xing
Keyword(s):  
Thin Film ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Crystal Morphology ◽  
Growth Conditions ◽  
Photoluminescence Spectra ◽  
Experimental Conditions ◽  
Grain Sizes ◽  
Power Inputs ◽  
Scanning Electron

This study prepared an SiC thin film by using the ratio frequency magnetron sputtering method, investigated the effects of different sputtering powers on the SiC material and analysed the changes in crystal morphology and photoluminescence characteristics caused by changes in the growth conditions used. It was considered that there was 6H-SiC crystal morphologies in the SiC thin film under the experimental conditions prevailing in this study. The SiC morphologies with small grain sizes intermingled and therefore formed anSiC thin film. The analyses of the photoluminescence spectra and Scanning Electron Microscope indicated that the SiC thin film materials with preferable crystal compositions could be prepared under appropriate power inputs.

Effect of Deposition Potential and Bath Temperature on One-Step Electrochemical Synthesis of One and Two Dimensional Nanostructured ZnO Thin Films on Fluorine Doped Tin Oxide Substrates

2019 ◽  
Vol 19 (11) ◽  
pp. 7014-7025 ◽  
Author(s):  
T. Marimuthu ◽  
N. Anandhan ◽  
R. Thangamuthu ◽  
S. Surya ◽  
R. Panneerselvam ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Film Thickness ◽  
Tin Oxide ◽  
Electrochemical Impedance ◽  
Dye Sensitized Solar Cells ◽  
Deposition Potential ◽  
Zno Films ◽  
Zinc Hydroxide ◽  
Sem Images ◽  
Zinc Deposition

Different zinc oxide (ZnO) morphologies such as platelets, nanowalls and nanorods were electrochemically synthesized on fluorine doped tin oxide (FTO) substrates by varying the deposition potentials and bath temperatures, respectively. Cyclic voltammetry (CV) curves reveal that ZnO deposition potentials are decreased as the bath temperatures are increased. X-ray diffraction (XRD) patterns and transmission electron microscope (TEM) images confirm that the synthesized ZnO nanostructures are hexagonal wurtzite structure. The XRD results reveal that the crystallinity of the films is increased when ZnO deposition potentials and temperatures are increased. Field emission scanning electron microscope (FE-SEM) images display platelets, nanowalls and nanorods structures for films synthesized -1.1 V, -1.2 V and -1.3 V respectively. The increase in deposition potential not only increases the growth rate of ZnO with metallic zinc deposition, but also decreases zinc hydroxide chloride hydrate. Fourier transform infrared microscope (FTIR) spectra confirm that the formation of zinc hydroxide (Zn(OH)2) is decreased as the bath temperatures are increased from 30 to 70 °C. Photoluminescence (PL) spectra depict that the crystal quality of the ZnO films are notably improved as the bath temperatures are increased. The film thickness is increased as the deposition potentials and bath temperatures are increased. The dye absorbance is increased with respect to the film thickness. The efficiencies of dye sensitized solar cells (DSSCs) fabricated with diverse morphologies such as platelets, nanowalls and nanorods are found to be 0.10, 0.49 and 0.47%, respectively. Electrochemical impedance spectroscopy (EIS) spectra reveal that the charge transfer recombination resistance (Rrec) is continuously decreased as metal zinc deposition is increased in ZnO films with increase in deposition potentials.

Effect of Annealing on Nanocrystalline Structure of Nb3Sn Diffusion Layers in Composites with Internal Tin Sources

2010 ◽  
Vol 297-301 ◽  
pp. 126-131 ◽  
Author(s):  
E.N. Popova ◽  
Vladimir V. Popov ◽  
E.P. Romanov ◽  
S.V. Sudareva ◽  
L.V. Elohina ◽  
...  
Keyword(s):  
Grain Size ◽  
Carrying Capacity ◽  
Nanocrystalline Structure ◽  
Diffusion Annealing ◽  
External Diameter ◽  
High Temperature Annealing ◽  
Grain Sizes ◽  
Diffusion Layers ◽  
Average Grain Size ◽  
Complete Transformation

Multifilamentary Nb3Sn-based superconducting composites manufactured by an internal-tin method have been studied by transmission (TEM) and scanning (SEM) electron microscopy. The main goal of this study is to reveal the effect of diffusion annealing regimes as well as the external diameter of the wires on the structure of nanocrystalline Nb3Sn layers (average grain size, grain size distribution, layer thickness, amount of Sn, etc.). It is demonstrated that multistep diffusion annealing results in quite a complete transformation of Nb filaments into Nb3Sn though some amount of the residual Nb remains in the filaments center. With an external diameter decrease the superconducting layers structure has been found to refine and get somewhat more uniform. An additional high-temperature annealing results in marked growth of Nb3Sn grain sizes and their scattering in sizes, which may negatively affect the current-carrying capacity of a wire.

scholarly journals THE EFFECT OF THE ELECTRON-OPAQUE PORE MATERIAL ON EXCHANGES THROUGH THE NUCLEAR ANNULI

1965 ◽  
Vol 25 (1) ◽  
pp. 43-53 ◽  
Author(s):  
Carl M. Feldherr
Keyword(s):  
Particle Size ◽  
Electron Microscope ◽  
Nuclear Envelope ◽  
Colloidal Gold ◽  
Maximum Size ◽  
Amoeba Proteus ◽  
Gold Particles ◽  
High Concentrations

To investigate the extent to which the electron-opaque pore material can regulate nucleocytoplasmic exchanges which occur through the nuclear annuli, experiments were performed in which polyvinylpyrrolidone (PVP)-coated colloidal gold particles (25 to 170 A in diameter) were microinjected into the cytoplasm of amebas (Amoeba proteus). The cells were fixed at various times after injection and examined with the electron microscope in order to determine the location of the gold particles. High concentrations of gold were found associated with the pore material at specific points adjacent to and within the pores. It is tentatively suggested that such specific accumulations could be a means of selecting substances from the cytoplasm for transport through the pores. Particles were also scattered throughout the ground cytoplasm and nucleoplasm. A comparison of the diameters of particles located in these two regions showed that the ability of materials to penetrate the nuclear envelope is a function of their size. It was estimated that the maximum size of the particles able to enter the nucleus is approximately 125 to 145 A indiameter. The regulation of exchanges with regard to particle size is thought to be dependent on the specific organization of the electron-opaque pore material.

High Tensile Ductility in Electrodeposited Bulk Nanocrystalline Ni–W Alloys

2014 ◽  
Vol 922 ◽  
pp. 497-502 ◽  
Author(s):  
Isao Matsui ◽  
Yorinobu Takigawa ◽  
Kenji Higashi
Keyword(s):  
Tensile Strength ◽  
Tensile Ductility ◽  
Nanocrystalline Structure ◽  
High Strength ◽  
Complexing Agent ◽  
Grain Sizes ◽  
Saccharin Sodium ◽  
Bulk Nanocrystalline ◽  
20 Nm ◽  
Sulfamate Bath

Bulk nanocrystalline Ni–W alloys were electrodeposited from a sulfamate bath that contained saccharin sodium as a gloss agent, and propionic acid and sodium gluconate as a complexing agent (SPG bath) to understand the tensile behavior. SPG bath with 1.0 and 5.0 g/L saccharin sodium at 45 ºC produced the bulk specimens with W content of 3.4 and 1.5 at.%, respectively. The electrodeposited alloys had a nanocrystalline structure with grain sizes of approximately 20 nm and a stronger (111) texture. The bulk nanocrystalline Ni–3.4 at.%W alloys deposited from an SPG bath with 1.0 g/L saccharin sodium exhibited a tensile strength of 1.6 GPa and tensile ductility of 1.8%. The bulk nanocrystalline Ni–1.5 at.%W alloys deposited from an SPG bath with 5.0 g/L saccharin sodium exhibited a tensile strength of 1.4 GPa and tensile ductility of 1.7%. The bulk nanocrystalline Ni–W alloys with a stronger (111) texture showed high strength and low plasticity.

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