scholarly journals SURFACE MORPHOLOGY AND SPUTTERING OF FeCrAl COATING ON STEEL EXPOSED TO LOW-ENERGY DEUTERIUM PLASMAS

2019 ◽  
pp. 190-194
Author(s):  
V.N. Voyevodin ◽  
G.D. Tolstolutskaya ◽  
A.V. Nikitin ◽  
R.L. Vasilenko ◽  
A.S. Kuprin ◽  
...  
Keyword(s):  
Pure Iron ◽  
Room Temperature ◽  
Nitrogen Atmosphere ◽  
Low Energy ◽  
Vacuum Arc ◽  
Published Data ◽  
Deuterium Plasma ◽  
X Ray ◽  
Order Of Magnitude ◽  
Sputtering Yields

Processes of sputtering and surface modification of FeCrAl coatings deposited on steel by vacuum arc was studied under the influence of low-energy (500 eV) deuterium plasma with fluence (4⋅1024) D+/m2 at room temperature. It was determined the composition of coatings by an energy dispersive X-ray spectrometer allowed to establish that the elements in the coatings are distributed more evenly when it coated in a nitrogen atmosphere. Results of erosion studies indicated that the sputtering yields for deuterium on coatings are 1.3…0.45 at./ion and at least two-three times less in comparison with initial alloys and published data for pure iron and chromium. For coatings deposited in a nitrogen atmosphere found that the obtained sputtering coefficients are almost an order of magnitude smaller in comparison with published data for pure iron and chromium and only 1.8 times higher compared to tungsten.

scholarly journals DEUTERIUM TRAPPING AND SPUTTERING OF TUNGSTEN COATINGS EXPOSED TO LOW-ENERGY DEUTERIUM PLASMA

2020 ◽  
pp. 54-59
Author(s):  
G.D. Tolstolutskaya ◽  
A.S. Kuprin ◽  
A.V. Nikitin ◽  
I.E. Kopanets ◽  
V.N. Voyevodin ◽  
...  
Keyword(s):  
Room Temperature ◽  
Low Energy ◽  
Deuterium Plasma ◽  
Martensitic Steels ◽  
Order Of Magnitude ◽  
Cathodic Arc Evaporation ◽  
Deuterium Retention ◽  
Sputtering Yields ◽  
Arc Evaporation ◽  
Cathodic Arc

Processes of sputtering, surface modification and deuterium retention of tungsten coatings were studied under the influence of low-energy (500 eV) deuterium plasma with fluence (21024 D+/m2) at room temperature. The method of cathodic arc evaporation was used to deposit W and WN-coatings on stainless steel. Results of erosion studies indicated that the sputtering yields for coatings WN and W are 3.110-3 and 4.810-3 at./ion, respectively, and at least two times larger compared to bulk W but almost an order of magnitude smaller compared to ferritic martensitic steels. The total D retentions of W coatings were on the order of 51019 D/m2 and around one orders of magnitude lower than that of WN.

scholarly journals Surface modification and sputtering of FeCrAl alloys exposed to low-energy hydrogen plasmas

2019 ◽  
pp. 73-80
Author(s):  
Galina D. Tolstolutskaya ◽  
Michael A. Tikhonovsky ◽  
Victor N. Voyevodin ◽  
Arkadiy V. Nikitin ◽  
Aleksander S. Tortika ◽  
...  
Keyword(s):  
Surface Modification ◽  
Grain Boundaries ◽  
Hydrogen Plasma ◽  
Low Energy ◽  
Published Data ◽  
X Ray ◽  
Hydrogen Plasmas ◽  
Sputtering Yields ◽  
Scanning Electron

In the present paper processes of sputtering and surface modification of commercial and experimental FeCrAl composites alloyed with yttrium, molybdenum and zirconium were investigated. Using a field-emission scanning electron microscope, it was shown that under the influence of low-energy (500 eV) hydrogen plasma with a flux about 3.2 ⋅ 1020 m–2 ⋅ s–1 and fluence 4 ⋅ 1024 m–2 at Troom, surface morphology develops due to the formation of grooves along grain boundaries, macro- and microcracks, as well as intragranular pits due to the sputtering of precipitates. Determination of the composition of precipitates by an energy dispersive X-ray spectrometer allowed to establish that aluminum oxide is preferentially distributed in the grains of FeCrAl-based alloys, and yttrium oxides are localized along grain boundaries. Results of erosion studies indicated that the sputtering yields for hydrogen on all alloys are 1.05– 0.38 at./ion and doesn’t exceed those for published data for pure iron and chromium. For experimental alloys doped with yttrium and molybdenum found that the obtained sputtering coefficients were in several times lower than for steel SS304 and only one and a half times higher compared to tungsten.

Structure and Conductivity of Iodine-Doped C60 Thin Films

1994 ◽  
Vol 359 ◽  
Author(s):  
Jun Chen ◽  
Haiyan Zhang ◽  
Baoqiong Chen ◽  
Shaoqi Peng ◽  
Ning Ke ◽  
...  
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Room Temperature ◽  
Conductivity Measurements ◽  
X Ray Diffraction ◽  
Temperature Conductivity ◽  
Room Temperature Conductivity ◽  
X Ray ◽  
Thermally Activated ◽  
Order Of Magnitude

ABSTRACTWe report here the results of our study on the properties of iodine-doped C60 thin films by IR and optical absorption, X-ray diffraction, and electrical conductivity measurements. The results show that there is no apparent structural change in the iodine-doped samples at room temperature in comparison with that of the undoped films. However, in the electrical conductivity measurements, an increase of more that one order of magnitude in the room temperature conductivity has been observed in the iodine-doped samples. In addition, while the conductivity of the undoped films shows thermally activated temperature dependence, the conductivity of the iodine-doped films was found to be constant over a fairly wide temperature range (from 20°C to 70°C) exhibiting a metallic feature.

Intercalation of Acceptors and Donors in Highly Ordered Graphite Fibers

1982 ◽  
Vol 20 ◽  
Author(s):  
T.C. Chieu ◽  
G. Timp ◽  
M.S. Dresselhaus
Keyword(s):  
Raman Spectroscopy ◽  
Room Temperature ◽  
Skin Depth ◽  
X Ray Diffraction ◽  
Repeat Distance ◽  
Temperature Conductivity ◽  
Room Temperature Conductivity ◽  
X Ray ◽  
Order Of Magnitude ◽  
Graphite Fibers

ABSTRACTThe intercalation of various acceptors and donors into graphite fibers, prepared from benzene-derived precursor materials is investigated by Raman spectroscopy, x-ray diffraction, electron diffraction, lattice fringing, and electrical resistivity measurements. Evidence for formation of well-staged acceptor compounds is provided by Debye-Scherrer x-ray diffraction which probes the bulk fiber and by Raman spectroscopy which probes an optical skin depth (< 0.1 μm). Lattice fringing measurements provide direct observation of large regions (up to 50 Aring; × 400 Aring;) of defectfree single-staged regions. Values for the c-axis repeat distance Ic are obtained by indexing (00l) lines of the x-ray diffraction pattern. Raman results show characteristic upshifted modes for stage 1 acceptor compounds with a sharpening in linewidth as compared to the E2g2 mode of the pristine fiber. The room temperature electrical conductivity is increased about an order of magnitude upon intercalation and exhibits a metallic dependence on temperature. The highest air-stable room temperature conductivity 1.4 × 105 (Ω-cm)−l ever reported for an intercalated fiber has been achieved.

scholarly journals The growth of Nd:CaWO4 single crystals

2003 ◽  
Vol 68 (12) ◽  
pp. 1001-1009 ◽  
Author(s):  
Aleksandar Golubovic ◽  
Slobodanka Nikolic ◽  
Rados Gajic ◽  
Stevan Djuric ◽  
Andreja Valcic
Keyword(s):  
Single Crystals ◽  
Room Temperature ◽  
Chromic Acid ◽  
Critical Diameter ◽  
Published Data ◽  
Hydrodynamic Equations ◽  
Czochralski Technique ◽  
Critical Rate ◽  
X Ray ◽  
C 30

CaWO4 doped with 0.8 % at. Nd (Nd:CaWO4) single crystals were grown from the melt in air by the Czochralski technique. The critical diameter dc = 1.0 cm and the critical rate of rotation ?c = 30 rpm were calculated from hydrodynamic equations for buoyancy-driven and forced convection. The rate of crystal growth was experimentally obtained to be 6.7 mm/h. For chemical polishing, a solution of 1 part saturated chromic acid (CrO3 in water) and 3 parts conc. H3PO4 (85 %) at 433 K with an exposure time of 2 h was found to be adequate. A mixture of 1 part concentrated HF and 2 parts chromic acid at room temperature after exposure for 30 min was found to be a suitable etching solution. The lattice parameters a = 0.52404 (6) nm, c = 1.1362 (6) nm and V0 = 0.312 (2) nm3 were determined by X-ray powder diffraction. The obtained results are discussed and compared with published data.

scholarly journals Room-Temperature Preparation of Ta Ions-Containing Ionic Liquid and its Vapor Deposition toward Ta-Oxide Film Coating

2022 ◽  
Author(s):  
Nana Hozuki ◽  
Kenichi Kaminaga ◽  
Shingo Maruyama ◽  
Daisuke Shiga ◽  
Hiroshi Kumigashira ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Oxide Film ◽  
Room Temperature ◽  
Film Coating ◽  
Metal Plate ◽  
Photoemission Spectroscopy ◽  
X Ray ◽  
Vacuum Forming ◽  
Order Of Magnitude ◽  
Temperature Preparation

Abstract Ta ions-containing solutions, which are brown in color with no precipitation, were successfully prepared through an electroelution process with ionic liquid (IL). An as-delivered Ta metal plate covered with a passivation oxide film could be easily eluted even at room temperature by simply applying an anodic potential of, e.g. +2.2 V vs. Ag in [Bmim][PF6] IL. According to the quantity of electric charge required for oxidation of Ta, most Ta ions in the IL were suggested to be in an oxidation state of +5, which was also confirmed by x-ray photoemission spectroscopy (XPS). Ta ions in IL were found to thermally evaporate together with IL molecules by heating in a vacuum, forming a deposit of the Ta ions-containing IL on a substrate. The Ta concentrations in the deposits were reduced uniquely by about one order of magnitude from those in the original bulk source through the evaporation process under the present conditions. Furthermore, a possibility of the formation of thin film-like Ta oxide from such a Ta ions-containing IL deposit and its bulk droplet prepared on substrates by annealing in air at 1000oC will be discussed.

Vapour growth, morphology, absolute structure and pyroelectric coefficient of meta-nitroaniline single crystals

2019 ◽  
Vol 52 (3) ◽  
pp. 564-570 ◽  
Author(s):  
Rolf Hesterberg ◽  
Michel Bonin ◽  
Martin Sommer ◽  
Matthias Burgener ◽  
Bernhard Trusch ◽  
...  
Keyword(s):  
Room Temperature ◽  
Vapour Phase ◽  
Pyroelectric Coefficient ◽  
Growth Speed ◽  
Published Data ◽  
X Ray ◽  
X Ray Crystallography ◽  
Absolute Structure ◽  
Good Agreement

The growth speed of (hkl) faces in the vapour phase, the absolute structure obtained by X-ray crystallography, and the value and the sign of the pyroelectric coefficient of meta-nitroaniline (mNA) were analysed in detail. The in situ observation of morphologically well developed faces of several mNA crystals growing in evacuated ampoules reveals no pronounced growth speed anisotropy for polar faces defining the unique axis 2 of the mm2 group. Scanning pyroelectric microscopy confirms mono-domain mNA crystals. X-ray measurements in the space group Pca21 show that the molecular planes coincide with the {\bar 211} and {\bar 2\bar 1\bar 1} faces, and the nitro groups cover the {201} face in the opposite direction to the crystal tip, characterizing the polar habitus studied here. At room temperature, the sign of the pyroelectric coefficient is positive for a measured effective value of 6.3 µC m−2 K−1, in good agreement with values reported by other authors. From previous elastic and piezoelectric published data, the secondary pyroelectric effect was calculated to be positive and far greater than the effective one, yielding a negative value for the primary pyroelectric coefficient.

X-Ray Fluorescence Analysis at Room Temperature with an Energy Dispersive Mercuric Iodide Spectrometer

1979 ◽  
Vol 23 ◽  
pp. 249-256
Author(s):  
M. Singh ◽  
A.J. Dabrowski ◽  
G.C. Huth ◽  
J.S. Iwanczyk ◽  
B.C. Clark ◽  
...  
Keyword(s):  
Room Temperature ◽  
Fluorescence Analysis ◽  
Low Energy ◽  
Cryogenic Cooling ◽  
Energy Dispersive ◽  
Entrance Window ◽  
X Rays ◽  
Mercuric Iodide ◽  
X Ray ◽  
Present Design

We have previously reported on the uniqueness and potential of room-temperature spectrometry of low-energy x-rays with a mercuric iodide (HgI2) detector (1,2,3). In this paper we emphasize the use of HgI2 detectors for x-ray fluorescence (XRF) analysis.Because no vacuum plumbing or cryogenic cooling is required, the design of a mercuric iodide room-temperature x-ray spectrometer is extremely simple. Our present design consists of coupling a detector directly to the first-stage FET in a modified Tennelec 161 D preamplifier and making the configuration “light-tight”. Aside from providing a suitable entrance window, there are no other requirements for routine spectroscopy.

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