Radiation tolerance of nanostructured TiCrN coatings

Nanostructured TixCr1–xN coatings of various compositions 0.58 ≤ x ≤ 0.8 on the substrates made of AISI 304 stainless steel and monocrystalline silicon were formed by the method of separable vacuum-arc deposition. The elemental composition was studied by Rutherford backscattering spectrometry of helium ions. The structural-phase state and the morphology were examined by X-ray diffraction, optical and scanning electron microscopy, tribomechanical tests of the initial coatings were also carried out. The radiation tolerance of the nanostructured TixCr1–xN coatings within 0.58 ≤ x ≤ 0.8 under He+ ion irradiation with an energy of 500 keV in the fluence range of 5·1016–3·1017 ions/cm2 was studied for the first time. It was found that the TixCr1–xN coatings within 0.58 ≤ x ≤ 0.8 withstand irradiation without significant changes in the structure up to a fluence of 2·1017 ions/cm2, when a partial coating flaking (exfoliation) up to a depth of the projected range of helium ions takes place. A decrease in the average size of crystallites of coatings and the crystal lattice period reduction after radiation exposure were detected. The decrease in the microhardness of the TixCr1–xN coatings of all compositions after irradiation was found.

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Superparamagnetic Behavior of Granular Co-C Films Consisting of Nanocrystalline Cobalt Encapsulated in Carbon

MRS Proceedings ◽

10.1557/proc-614-f2.7.1 ◽

2000 ◽

Vol 614 ◽

Cited By ~ 2

Author(s):

Hao Wang ◽

S.P. Wong ◽

W.Y. Cheung ◽

N. Ke ◽

M.F. Chiah ◽

...

Keyword(s):

Photoelectron Spectroscopy ◽

Rutherford Backscattering Spectrometry ◽

Magnetic Measurements ◽

Magnetic Hysteresis ◽

Blocking Temperature ◽

Vacuum Arc ◽

Zero Field ◽

X Ray Diffraction ◽

X Ray ◽

Force Microscopy

ABSTRACTNanocomposite Co-C thin films of about 15 nm thick were prepared by pulsed filtered vacuum arc deposition. The films were characterized by x-ray photoelectron spectroscopy, non-Rutherford backscattering spectrometry, x-ray diffraction, magnetic force microscopy and magnetic measurements. The as-deposited films were amorphous. After annealing at 350°C for one hour in vacuum (< 10−3 Pa), the films were found to consist of nanocrystalline Co grains encapsulated in carbon. The superparamagnetism of the annealed Co36C64 film was demonstrated by the measurement of DC susceptibility and magnetic hysteresis using a SQUID magnetometer. The superparamagnetic relaxation blocking temperature was marked to be about 12K by the peak of the zero-field-cooled magnetization under a field of 100 Oe. The magnetic properties of these annealed granular Co-C films transform from superparamagnetism to ferromagnetism when the Co concentration increases.

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Effects of High Energy Ion Irradiation on Crystallization of Amorphous Germanium Films Deposited on Calcium Fluoride Substrates

MRS Proceedings ◽

10.1557/proc-396-191 ◽

1995 ◽

Vol 396 ◽

Author(s):

Setsuo Nakao ◽

Kazuo Saitoh ◽

Masami Ikeyama ◽

Hiroaki Niwa ◽

Seita Tanemura ◽

...

Keyword(s):

Thin Film ◽

Calcium Fluoride ◽

Structural Changes ◽

Rutherford Backscattering Spectrometry ◽

Ion Irradiation ◽

High Energy ◽

The Other ◽

Ion Current ◽

X Ray Diffraction ◽

X Ray

AbstractAmorphous (a-) Ge films were deposited on air-cleaved CaF2 (111) substrates at different deposition temperatures (Td). The films were irradiated with 0.9 MeV Ge or Si ions at low ion current intensity (1c) l00nA/cm2. Their structural changes were studied by Rutherford backscattering spectrometry (RBS) -channeling technique and thin film x-ray diffraction (XRD) measurement. It was found that the films were epitaxially crystallized by Ge and Si ion irradiation although they included randomly oriented grains. Ge ion irradiation was more effective for the crystallization than Si ion irradiation. However, the amount of the randomly oriented grains was slightly higher when using Ge ions. On the other hand, ion irradiation to the films prepared at high Td also exhibited higher incidence of randomly oriented grains.

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Thermally and Ion-Induced Reactions of Metal with CuO Substrate

MRS Proceedings ◽

10.1557/proc-128-255 ◽

1988 ◽

Vol 128 ◽

Author(s):

Jian Li ◽

S. Q. Wang ◽

J. W. Mayer

Keyword(s):

Thermal Annealing ◽

Vacuum Annealing ◽

Rutherford Backscattering Spectrometry ◽

Ion Irradiation ◽

Chemical Reactivity ◽

Metal Layer ◽

X Ray Diffraction ◽

X Ray ◽

Heats Of Reaction ◽

Made In

ABSTRACTThermally and ion-induced reactions of transition metals Zr, Ti, Cr and Ag with CuO substrates have been studied by Rutherford backscattering spectrometry and X-ray diffraction techniques. Reactions resulted in the configuration of ZrO2/Cu2O/CuO from Zr/CuO structure and TiOx/Cu2O from Ti/CuO structure after thermal annealing and ion irradiation. No significant reaction has been found in Cr/CuO after vacuum annealing at 410°C and 300 Key Xe ions irradiation at 240°C. Ag atoms balled up on CuO surface after annealing at 610°C. A comparison of the reaction layers has been made in both metal/SiO2 and metal/CuO systems after thermal annealing and ion irradiation. Both heats of reaction and bond strength in the substrates can influence the chemical reactivity between metal layer and substrate.

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Examination of Interact Roughening in Ion Irradiated Cu/Nb Films by Computer Simulation and by X-Ray Diffraction

MRS Proceedings ◽

10.1557/proc-396-107 ◽

1995 ◽

Vol 396 ◽

Cited By ~ 3

Author(s):

P.J. Partyka ◽

R.S. Averback ◽

I.K. Robinson ◽

Y.S. Lee ◽

C.P. Flynn ◽

...

Keyword(s):

Computer Simulation ◽

Rutherford Backscattering Spectrometry ◽

Ion Irradiation ◽

X Ray Diffraction ◽

State Behavior ◽

X Ray ◽

Monte Carlo Computer Simulation ◽

Immiscible System ◽

Crystal Truncation Rod ◽

Steady State Behavior

AbstractInterfacial roughening during ion irradiation of an immiscible system is investigated by Monte Carlo computer simulation and by an x-ray diffraction technique called crystal truncation rod (CTR) analysis. In the simulations, ion flux and sample temperature are varied, and the system is allowed to evolve under irradiation until it reaches a steady state behavior. The observed behaviors are then sought experimentally in the Cu/Nb system implanted with 2 MeV Kr+ ions at different sample temperatures. Analysis of the roughness at the Cu interface is based upon the existence of a crystal truncation rod, which contains information on exactly how the crystal is terminated, or, in other words, the interfacial roughness. Rutherford backscattering spectrometry (RBS) is also used to study the intermixing of the Cu and Nb layers.

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In Vitro Assessment of Hydroxyapatite Coating on the Surface of Additive Manufactured Ti6Al4V Scaffolds

Materials Science Forum ◽

10.4028/www.scientific.net/msf.879.2444 ◽

2016 ◽

Vol 879 ◽

pp. 2444-2449 ◽

Cited By ~ 1

Author(s):

Ekaterina Chudinova ◽

Maria Surmeneva ◽

Andrey Koptioug ◽

Irina V. Savintseva ◽

Irina Selezneva ◽

...

Keyword(s):

Stem Cells ◽

Mesenchymal Stem Cells ◽

Human Mesenchymal Stem Cells ◽

Nanocrystalline Structure ◽

X Ray Diffraction ◽

Ha Coating ◽

Magnetron Sputter Deposition ◽

In Vitro Assessment ◽

Average Size

Custom orthopedic and dental implants may be fabricated by additive manufacturing (AM), for example using electron beam melting technology. This study is focused on the modification of the surface of Ti6Al4V alloy coin-like scaffolds fabricated via AM technology (EBM®) by radio frequency (RF) magnetron sputter deposition of hydroxyapatite (HA) coating. The scaffolds with HA coating were characterized by Scanning Electron microscopy, X-ray diffraction. HA coating showed a nanocrystalline structure with the crystallites of an average size of 32±9 nm. The ability of the surface to support adhesion and the proliferation of human mesenchymal stem cells was studied using biological short-term tests in vitro. In according to in vitro assessment, thin HA coating stimulated the attachment and proliferation of cells. Human mesenchymal stem cells cultured on the HA-coated scaffold also formed mineralized nodules.

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The impact of point defects in n-type GaN layers on thermal decomposition of InGaN/GaN QWs

Scientific Reports ◽

10.1038/s41598-021-81017-w ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Mikolaj Grabowski ◽

Ewa Grzanka ◽

Szymon Grzanka ◽

Artur Lachowski ◽

Julita Smalc-Koziorowska ◽

...

Keyword(s):

Quantum Wells ◽

High Temperatures ◽

Point Defects ◽

X Ray Diffraction ◽

Helium Ions ◽

X Ray ◽

Sapphire Substrates ◽

Transmission Electron ◽

The Impact ◽

Ingan Quantum Wells

AbstractThe aim of this paper is to give an experimental evidence that point defects (most probably gallium vacancies) induce decomposition of InGaN quantum wells (QWs) at high temperatures. In the experiment performed, we implanted GaN:Si/sapphire substrates with helium ions in order to introduce a high density of point defects. Then, we grew InGaN QWs on such substrates at temperature of 730 °C, what caused elimination of most (but not all) of the implantation-induced point defects expanding the crystal lattice. The InGaN QWs were almost identical to those grown on unimplanted GaN substrates. In the next step of the experiment, we annealed samples grown on unimplanted and implanted GaN at temperatures of 900 °C, 920 °C and 940 °C for half an hour. The samples were examined using Photoluminescence, X-ray Diffraction and Transmission Electron Microscopy. We found out that the decomposition of InGaN QWs started at lower temperatures for the samples grown on the implanted GaN substrates what provides a strong experimental support that point defects play important role in InGaN decomposition at high temperatures.

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Temperature-induced structural phase transitions in RERhSn (RE = Y, Gd-Tm, Lu)

Zeitschrift für Kristallographie - Crystalline Materials ◽

10.1515/zkri-2021-2008 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Simon Engelbert ◽

Rolf-Dieter Hoffmann ◽

Jutta Kösters ◽

Steffen Klenner ◽

Rainer Pöttgen

Keyword(s):

Rare Earth ◽

Phase Transitions ◽

Driving Force ◽

Room Temperature ◽

Structural Phase ◽

Structural Phase Transitions ◽

Line Broadening ◽

X Ray Diffraction ◽

Temperature Dependent ◽

X Ray

Abstract The structures of the equiatomic stannides RERhSn with the smaller rare earth elements Y, Gd-Tm and Lu were reinvestigated on the basis of temperature-dependent single crystal X-ray diffraction data. GdRhSn crystallizes with the aristotype ZrNiAl at 293 and 90 K. For RE = Y, Tb, Ho and Er the HP-CeRuSn type (approximant with space group R3m) is already formed at room temperature, while DyRhSn adopts the HP-CeRuSn type below 280 K. TmRhSn and LuRhSn show incommensurate modulated variants with superspace groups P31m(1/3; 1/3; γ) 000 (No. 157.1.23.1) (γ = 3/8 for TmRhSn and γ = 2/5 for LuRhSn). The driving force for superstructure formation (modulation) is a strengthening of Rh–Sn bonding. The modulation is expressed in a 119Sn Mössbauer spectrum of DyRhSn at 78 K through line broadening.

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MOVPE Growth of Quaternary (Al,Ga,In)N for UV Optoelectronics

MRS Internet Journal of Nitride Semiconductor Research ◽

10.1557/s1092578300004580 ◽

2000 ◽

Vol 5 (S1) ◽

pp. 412-424

Author(s):

Jung Han ◽

Jeffrey J. Figiel ◽

Gary A. Petersen ◽

Samuel M. Myers ◽

Mary H. Crawford ◽

...

Keyword(s):

Room Temperature ◽

Rutherford Backscattering Spectrometry ◽

Optoelectronic Devices ◽

Lattice Parameter ◽

X Ray Diffraction ◽

X Ray ◽

Peak Energy ◽

Movpe Growth ◽

Pl Emission

We report the growth and characterization of quaternary AlGaInN. A combination of photoluminescence (PL), high-resolution x-ray diffraction (XRD), and Rutherford backscattering spectrometry (RBS) characterizations enables us to explore the contours of constant- PL peak energy and lattice parameter as functions of the quaternary compositions. The observation of room temperature PL emission at 351nm (with 20% Al and 5% In) renders initial evidence that the quaternary could be used to provide confinement for GaInN (and possibly GaN). AlGaInN/GaInN MQW heterostructures have been grown; both XRD and PL measurements suggest the possibility of incorporating this quaternary into optoelectronic devices.

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