Parameters for Nitrogen Diffusion in Ni, Ti, and Al Obtained from Implanted Bilayers

1992 ◽  
Vol 279 ◽  
Author(s):  
K. K. Bourdelle ◽  
D. O. Boerma
Keyword(s):  
Nuclear Reaction ◽  
Room Temperature ◽  
Vacuum Annealing ◽  
Nitride Layer ◽  
Nuclear Reaction Analysis ◽  
Nitrogen Diffusion ◽  
Depth Profiles ◽  
Solid Interface ◽  
Before And After ◽  
Concentration Depth Profiles

ABSTRACTNi foils and samples consisting of bilayers of Ni or Fe on Al, Ti or Si were implanted at room temperature with 15N+ ions to fluences of around 1×l017 N/cm2. The concentration depth profiles of 15N were determined with nuclear reaction analysis before and after vacuum annealing. It was found that the penetrability for N atoms of the surface and the solid/solid interface plays an important role in the N redistribution during implantation or annealing. The formation of a nitride layer or nitride clusters in Ni and Fe was deduced. Parameters for N migration determined for the metals under investigation are discussed in terms of models.

Heat-Resistant Barrier Contacts Made on the Basis of TiBx and ZrBx to SiC and GaN

2009 ◽  
Vol 615-617 ◽  
pp. 565-568 ◽  
Author(s):  
Alexander A. Lebedev ◽  
A.E. Belyaev ◽  
N.S. Boltovets ◽  
V.N. Ivanov ◽  
Raisa V. Konakova ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Phase Composition ◽  
Heat Resistance ◽  
Contact Structure ◽  
Schottky Barriers ◽  
Electrophysical Properties ◽  
Depth Profiles ◽  
Contact Metallization ◽  
Before And After ◽  
Concentration Depth Profiles

We studied the heat resistance of AuTiBx (ZrBx) barrier contacts to n-SiC 6H and n-GaN. The Schottky barrier diode (SBD) parameters, the concentration depth profiles for contact structure components and the phase composition of contact metallization were measured both before and after rapid thermal annealing (RTA) at temperatures up to 900 °С (1000 °С) for contacts to GaN (SiC 6H). It is shown that the layered structure of metallization and electrophysical properties of Schottky barriers (SBs) remain stable after RTA, thus indicating their heat resistance. The ideality factor n of the I-V characteristic of SBDs after RTA was 1.2, while the SB height φВ was ~0.9 eV (~0.8 eV) for the gallium nitride (silicon carbide) barrier structures.

The synergies between displacement damage creation and hydrogen presence: the effect of D ion energy and flux

2022 ◽  
Author(s):  
Sabina Markelj ◽  
Matic Pečovnik ◽  
Thomas Schwarz-Selinger ◽  
Mitja Kelemen
Keyword(s):  
Nuclear Reaction ◽  
Thermal Desorption ◽  
Rate Equation ◽  
Irradiation Time ◽  
Thermal Desorption Spectroscopy ◽  
Nuclear Reaction Analysis ◽  
Displacement Damage ◽  
Ion Energy ◽  
Depth Profiles ◽  
Different Temperatures

Abstract In this work the synergism between displacement damage creation and presence of hydrogen isotopes was studied. Tungsten samples were irradiated by 10.8 MeV W ions with or without the presence of D ions with two different energies of 300 eV/D and 1000 eV/D and different temperatures. In order to compare the results obtained with different exposure parameters the samples were afterwards additionally exposed to D ions at 450 K to populate the created defects. By increasing the W irradiation time, ion flux and energy, the increase of D concentration and D retention was observed as measured by nuclear reaction analysis and thermal desorption spectroscopy. By fitting the D depth profiles and D desorption spectra by the rate equation code MHIMS-R we could see that additional fill-levels were populated with higher flux and ion energy which ends up in higher final D concentration and retention as compared to experiments with lower D flux and energy.

18O study of the oxidation of reactively sputtered Ti1−xAlxN barrier

2001 ◽  
Vol 16 (9) ◽  
pp. 2591-2599 ◽  
Author(s):  
M. C. Hugon ◽  
F. Varniere ◽  
F. Letendu ◽  
B. Agius ◽  
I. Vickridge ◽  
...  
Keyword(s):  
Electrode Materials ◽  
Nuclear Reaction Analysis ◽  
Oxidation Reactions ◽  
Electrically Conductive ◽  
Al Content ◽  
Perovskite Materials ◽  
Sample Composition ◽  
Before And After ◽  
The Stability ◽  
Concentration Depth Profiles

The preparation of high-permittivity perovskite materials requires high-temperature (550–750 °C) oxidizing environments, providing stringent limitations on the choice of electrode materials. To minimize interdiffusion and oxidation reactions, an electrically conductive diffusion barrier such as Ti1−xAlxN is needed below the electrode material (Pt, IrO2, RuO2…). Ti1−xAlxN films were deposited by multitarget reactive sputtering in a mixture of Ar and N2. The stability of these films has been investigated under typical conditions for crystallization of perovskite dielectrics. Sample composition was characterized using Rutherford backscattering spectroscopy and nuclear reaction analysis. In particular, the concentration depth profiles of both 18O and 27Al were measured before and after RTA treatments via the narrow resonances of 18O(p,α)15N at 151 keV (FWHM = 100 eV) and 27Al(p,γ)28Si at 992 keV (FWHM = 100 eV). The different 18O excitation curves show that the oxidation resistance increases with Al incorporation. The Al excitation curves indicate a uniform Al content for as-deposited TixAl1−xN and reveal Al diffusion to the surface during the oxidation process which indicates the formation of an Al-rich oxide layer at the TixAl1−xN surface, leaving a layer depleted in Al below it.

Helium Migration Mechanisms in Polycrystalline Uranium Dioxide

2006 ◽  
Vol 985 ◽  
Author(s):  
Guillaume Martin ◽  
Pierre Desgardin ◽  
Philippe Garcia ◽  
Thierry Sauvage ◽  
Gaëlle Carlot ◽  
...  
Keyword(s):  
Grain Boundaries ◽  
Nuclear Reaction ◽  
Uranium Dioxide ◽  
Nuclear Reaction Analysis ◽  
Annealing Stage ◽  
Depth Profiles ◽  
Release Mechanisms ◽  
Helium Diffusion

AbstractThis study aims at identifying the release mechanisms of helium in uranium dioxide. Two sets of polycrystalline UO2 sintered samples presenting different microstructures were implanted with 3He ions at concentrations in the region of 0.1 at.%. Changes in helium concentrations were monitored using two Nuclear Reaction Analysis (NRA) techniques based on the 3He(d,α)1H reaction. 3He release is measured in-situ during sample annealing at temperatures ranging between 700°C and 1000°C. Accurate helium depth profiles are generated after each annealing stage. Results that provide data for further understanding helium release mechanisms are discussed. It is found that helium diffusion appears to be enhanced above 900°C in the vicinity of grain boundaries possibly as a result of the presence of defects.

Deuterium Interactions with Ion-Implanted Oxygen in Cu and Au

1988 ◽  
Vol 128 ◽  
Author(s):  
S. M. Myers ◽  
W. A. Swansiger ◽  
D. M. Follstaedt
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Ion Implantation ◽  
Nuclear Reaction ◽  
Room Temperature ◽  
Phase Changes ◽  
Nuclear Reaction Analysis ◽  
Temperature Range ◽  
Transmission Electron ◽  
First Time

ABSTRACTThe interactions of deuterium (D) with oxygen in Cu and Au were examined using ion implantation, nuclear-reaction analysis, and transmission electron microscopy. In Cu, the reduction of Cu2O precipitates by D to produce D20 was shown to occur readily down to room temperature, at a rate limited by the transport of D to the oxides. The reverse process of D2O dissociation was characterized for the first time below the temperature range of steam blistering. The evolution of the Cu(D)-Cu2O-D2O system was shown to be predicted by a newly extended transport formalism encompassing phase changes, trapping, diffusion, and surface release. In Au, buried 0 sinks were used to measure the permeability of D at 573 and 373 K, thereby extending the range of measured permeabilities downward by about six orders or magnitude.

Magnetron Sputtering High Temperature Mo-Al2O3 Cermet Solar Selective Coatings

2007 ◽  
Vol 546-549 ◽  
pp. 1773-1776 ◽  
Author(s):  
Xin Kang Du ◽  
Cong Wang ◽  
Tian Min Wang ◽  
Bu Liang Chen ◽  
Long Zhou ◽  
...  
Keyword(s):  
Room Temperature ◽  
Annealing Temperature ◽  
Vacuum Annealing ◽  
Layer Structure ◽  
Steel Substrate ◽  
Annealing Treatment ◽  
Solar Absorptance ◽  
Selective Coating ◽  
Before And After ◽  
Different Temperatures

Based on double cermet layer structure, Mo-Al2O3 cermet solar selective coating was prepared on stainless steel substrate. A solar absorptance of 0.92 and normal emittance of 0.19 at room temperature have been achieved. Vacuum annealing treatment was done and its influences on the solar selective performance was discussed. Absorptance changed between 0.90 and 0.92 under the selected annealing temperature range of 350-800°C, and emittance varied from 0.19 to 0.23 when heated at 650°C. The microstructures before and after annealing process at different temperatures were investigated.

Microstructure Evolution in Nitrogen Implanted Sapphire

2011 ◽  
Vol 275 ◽  
pp. 222-225
Author(s):  
John Kennedy ◽  
Jérôme Leveneur ◽  
Peter P. Murmu ◽  
Andreas Markwitz
Keyword(s):  
Room Temperature ◽  
Normal Incidence ◽  
Nuclear Reaction Analysis ◽  
Average Width ◽  
Force Microscopy ◽  
Ion Concentrations ◽  
Depth Profiles ◽  
Atomic Force ◽  
Nitrogen Ion ◽  
Temperature Dynamic

Low-energy 14N+ ions were implanted with 23 keV under normal incidence into C-axis (0001) sapphire at room temperature. DYNAMIC-TRIM calculations were performed to calculate the N depth profiles for the various fluences from 1x1016 to 1017 cm-2. Electron Beam Annealing (EBA) was performed at a sample temperature of 700 °C for 10 min to allow the implanted and substrate atoms in the implanted layer to move to energetically preferable positions. Nuclear Reaction Analysis revealed the implanted nitrogen ion concentrations. Atomic Force Microscopy and Scanning Electron Microscopy show some nanostructures at the surface of the sapphire substrate exhibiting an average width of 139 ± 25 nm and height of 37 ± 7 nm using the lowest fluence of 1x1016 ions cm-2. Notably for samples implanted with the highest fluence of 1x1017 ions cm-2, bubble/holes like structures appeared after EBA due to out-diffusion of nitrogen that causes blistering and exfoliation effects.

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