Temperature Dependence of Ion Beam Mixing in Al

1981 ◽  
Vol 7 ◽  
Author(s):  
S.T. Picraux ◽  
D. M. Follstaedt ◽  
J. Delafond
Keyword(s):  
Low Temperatures ◽  
Driving Forces ◽  
Ion Beam ◽  
Slow Motion ◽  
Ion Beam Mixing ◽  
Depth Profiles ◽  
Mixing Rates ◽  
Atomic Mixing ◽  
Concentration Depth Profiles

ABSTRACTThe atomic mixing of evaporated Al/Sb films and of Al/Ag films on Al<110> crystal substrates by 400 keV Xe ion beams has been investigated. Concentration depth profiles were measured in situ by 1.5 MeV He scattering as a function of Xe fluence from 2 to 32×1015 Xe/cm2. The initial mixing rates are similar at 85 and 300 K; mixing proceeds by rapid motion of Al (≈15 Al/Xe) into and uniformly through the thickness of the Sb film and by a slow motion of Sb (≈0.5 Sb/Xe) into the Al<110> substrate. More rapid Sb mixing into Al occurs for polycrystalline Al. The rate for Al into Sb slows at concentrations approaching the stable AlSb phase. Appreciably higher rates of Sb mixing into Al (2.2 to 2.8 Sb/Xe) occur at 575 K. Mixing rates for the highly soluble system, Al/Ag, are compared to the nearly insoluble Al/Sb at 85 and 300 K. Appreciably higher rates are found for Ag than for Sb, suggesting the influence of chemical driving forces even at these low temperatures.

Ion beam mixing study on Cu/Al2O3 bilayer samples using Rutherford backscattering spectrometry

1994 ◽  
Vol 9 (2) ◽  
pp. 406-409 ◽  
Author(s):  
A.G. Balogh ◽  
M-P. Macht ◽  
V. Naundorf
Keyword(s):  
Vapor Deposition ◽  
Rutherford Backscattering Spectrometry ◽  
Ion Beam ◽  
Rutherford Backscattering ◽  
Mixing Efficiency ◽  
Fusion Reactors ◽  
Ion Beam Mixing ◽  
Depth Profiles ◽  
Cu Alloys ◽  
Concentration Depth Profiles

Cu/Al2O3 bilayer samples were produced by vapor deposition and irradiated successively with 150 keV Ar ions up to a dose of 500 dpa. Ion beam mixing effects were studied by 2 Me V He+ Rutherford backscattering spectroscopy (RBS). Concentration depth profiles show the mixing of Cu, Al, and O atoms in the sample. Because of the low mixing efficiency found in this study, Al2O3-dispersion strengthened Cu alloys seem to be good candidates as structural materials in fusion reactors.

Ion-beam mixing of Ni/Pd layers: I. Cascade mixing regime (low temperature)

1988 ◽  
Vol 3 (6) ◽  
pp. 1057-1062 ◽  
Author(s):  
U. G. Akano ◽  
D. A. Thompson ◽  
J. A. Davies ◽  
W. W. Smeltzer
Keyword(s):  
Thin Film ◽  
Ion Beam ◽  
Heavy Ion ◽  
Square Root ◽  
Ion Beam Mixing ◽  
Dose Comparison ◽  
Mixing Regime ◽  
Constant Dose ◽  
Constant Dose Rate

A tomic mixing resulting from heavy-ion bombardment of thin-film Ni/Pd bilayers and thin Pd markers sandwiched between Ni layers has been investigated. Mixing experiments were performed over a temperature range 40–473 K, using 120 keV Ar+ and 145 keV Kr+ ions at a constant dose rate of 5.5 × 1012 ions cm −2s−1 for doses up to 4 × 1016cm−2. The resulting interdiffusion was measured, in situ, using Rutherford backscattering with 2−2.8 MeV 4He+ ions. The results showed that, for both markers and bilayers, the amount of mixing is similar for both configurations and varies linearly with the square root of the ion dose. Comparison of the induced mixing per ion, following irradiation at 40 K, shows that the mixing is dependent on the damage energy FD deposited at the interface region. The mixing is essentially athermal.

Ion-beam mixing of Ni/Pd layers: II. Thermally assisted regime (>500K)

1988 ◽  
Vol 3 (6) ◽  
pp. 1063-1071 ◽  
Author(s):  
U. G. Akano ◽  
D. A. Thompson ◽  
W. W. Smeltzer ◽  
J. A. Davies
Keyword(s):  
Grain Boundary ◽  
Ion Irradiation ◽  
Ion Beam ◽  
Effective Diffusivity ◽  
Bilayer Films ◽  
Diffusion Analysis ◽  
The Mean ◽  
Atomic Mixing ◽  
Lattice Diffusivity

Atomic mixing in Ni/Pd bilayer films due to 120 keV Ar+ irradiation in the thermally assisted regime (523−673 K) has been measured, in situ, using Rutherford backscattering with 2.0 MeV 4He+ ions. The mean diameter of grains in these polycrystallinc films increased from 10 to 60 nm, following Ar+ bombardment at 573 K. Initial mixing was rapid due to grain boundary diffusion and incorporation of the metal solute into the solvent metal matrix by grain growth; this mixing stage was essentially complete within 10 min for annealed films or after an Ar+ dose of 4 × 1015 cm−2 in irradiated films (10 min irradiation). No further measurable mixing occurred in the annealed, unirradiated films. For the irradiated samples the initial rapid mixing (6−35 atoms/ion) was followed by a slower mixing stage of 0.7–1.8 atoms/ion for irradiation doses of up to 2.5 × 1016 Ar+ cm−2. The Ar+ bombardment gave rise to much smaller mixing levels when the Pd films were deposited on large-grain or single-crystal Ni. A diffusion analysis demonstrates that the effective diffusivity, Deff, for ion-irradiation-enhanced mixing in the thermally assisted regime satisfied the relation Dl < Deff < DB, where the ratio of the grain boundary to lattice diffusivity was DB/Dl > 106.

Ion Mixing Kinetics of Thin Layered Films in the Fe-Al System

1983 ◽  
Vol 27 ◽  
Author(s):  
J. Grilhe ◽  
J.P. Riviere ◽  
J. Delafond ◽  
C. Jaouen
Keyword(s):  
Composition Range ◽  
Volume Fraction ◽  
Ion Beam ◽  
Mixed Volume ◽  
Low Doses ◽  
Ion Beam Mixing ◽  
Resistivity Measurements ◽  
Semi Empirical ◽  
Kinetics Of

ABSTRACTEvaporated bilayers and multilayers of Fe and Al have been studied during ion beam mixing with Xe ions using in-situ electrical resistivity measurements. Experiments have been performed in the composition range 40 – 58 at.% Al and at both temperatures 77 K and 300 K. A semi-empirical model is proposed to explain the observed kinetics. At low doses, a square root dependence of the mixed volume fraction on dose is found at 77 K but not at 300 K. The results are discussed by comparison with the different models proposed for ion beam mixing.

scholarly journals Use of Nuclear Techniques in the Characterization of Chrome Black Solar Absorber Surfaces

1979 ◽  
Vol 32 (4) ◽  
pp. 343 ◽  
Author(s):  
ZE Switkowski ◽  
JCP Heggie ◽  
GJ Clark ◽  
RJ Petty
Keyword(s):  
Ion Beam ◽  
Direct Capture ◽  
Depth Profiles ◽  
Solar Absorber ◽  
Solar Absorbers ◽  
Nuclear Techniques ◽  
Beam Analysis ◽  
Physical Features ◽  
Concentration Depth Profiles

A set of electrodeposited chrome black solar absorbers has been subjected to ion beam analysis in an attempt to determine the concentration depth profiles of the major elemental constituents. Chromium distributions were obtained using the 5 2Cr(p, )i)53Mn nuclear reaction, which is resonant at Ep = 1005�2 ke V. The possibility was investigated of inferring oxygen distributions from the )i-ray lineshapes (measured with a Ge(Li) detector) of the direct capture reaction 160(p, )i)17F. Concentration profiles were also obtained for fluorine and sodium contaminants in some chrome blacks. Complete experimental details are given of the various nuclear techniques used. The results of these measurements are discussed in terms of the microscopic physical features of the selective surfaces and are related to the known photothermal properties of the surfaces.

Why does Hydrogen Loss Rate Correlate with How Strongly Hydrogen Inhibits Ion Beam Mixing?

1989 ◽  
Vol 157 ◽  
Author(s):  
R. E. Wistrom ◽  
P. Borgesen
Keyword(s):  
Loss Rate ◽  
Ion Beam ◽  
Ion Beam Mixing ◽  
Mixing Rates ◽  
Loss Rates

ABSTRACTPrevious studies have shown that the presence of hydrogen in multilayer samples containing Ti reduces ion beam mixing rates. The present study sought to determine why the magnitude of this effect depends on which metal is mixed into Ti and why it is correlated to the rate at which hydrogen leaves the sample during mixing. Hydrogen loss rates of multilayers were compared with those of bilayer samples designed to minimize the effect of mixing. For bilayers, hydrogen loss rates were smaller and did not depend on which metal was mixed into Ti in the same way that multilayer loss rates do. This suggests that hydrogen leaves the multilayer samples because it is bound less strongly in the mixed regions than in the Ti. The primary cause of hydrogen loss is mixing rather than ion beam induced desorption.

scholarly journals Mixing of Al Into Uranium Silicides Reactor Fuels

1996 ◽  
Vol 439 ◽  
Author(s):  
Fu-Rong Ding ◽  
R. C. Birtcher ◽  
B. J. Kestel ◽  
P. M. Baldo
Keyword(s):  
Ion Beam ◽  
High Dose ◽  
Ion Beam Mixing ◽  
Dose Irradiation ◽  
Fuel Burn ◽  
Fission Gas ◽  
Mixing Rates ◽  
Radiation Induced ◽  
And Diffusion ◽  
Swelling Behaviors

AbstractSEM observations have shown that irradiation induced interaction of the aluminum cladding with uranium silicide reactor fuels strongly affects both fission gas and fuel swelling behaviors during fuel burn-up. We have used ion beam mixing, by 1.5 MeV Kr, to study this phenomena. RBS and the 27 A1( p, γ) 28 Si resonance nuclear reaction to was used to measure radiation induced mixing of Al into U3Si and U3Si2 after irradiation at 300γ;C.Initially U mixes into the Al layer and Al mixes into the U3 Si. At a low doses, the Al layer is converted into Ual4 type compound while near the interface the phase U(Al93 Si. 07 )3 grows. Under irradiation, Al diffuses out of the Ual4 surface layer, and the lower density ternary, which is stable under irradiation, is the final product. Al mixing into U3 Si2 is slower than in U3 Si, but after high dose irradiation the Al concentration extends much father into the bulk. In both systems Al mixing and diffusion is controlled by phase formation and growth. The Al mixing rates into the two alloys are similar to that of Al into pure uranium where similar aluminide phases are formed.

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