Effects of Different Methods of Calculating Mixed Depth Upon The Mixing Rates During Ion Beam Mixing

1985 ◽  
Vol 45 ◽  
Author(s):  
D. B. Poker ◽  
B. R. Appleton
Keyword(s):  
Ion Beam ◽  
Error Function ◽  
Square Root ◽  
Ion Beam Mixing ◽  
Methods Of Calculation ◽  
Mixing Rates

ABSTRACTThe linearity of mixing rates of ion-beam mixing of metals on silicon has been found to depend critically upon the method by which the mixed depth is calculated. For nonstoichiometric mixing, several methods of calculating the mixed depth may be used, namely: integrated area, halfheight, moment, error function, and 10%-90%. When applied to the same data, these methods can yield divergent results, from linear to square-root dependences of the mixed depth upon the mixing dose. For stoichiometric mixing, the calculation of mixed depth is more straightforward, but different methods of calculation still yield widely differing results. Possible causes for these discrepancies are discussed.

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.

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.

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.

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.

Nanostructuration of Cr/Si layers induced by ion beam mixing

2013 ◽  
Vol 1514 ◽  
pp. 61-68
Author(s):  
L. Luneville ◽  
L. Largeau ◽  
C. Deranlot ◽  
N. Moncoffre ◽  
Y. Serruys ◽  
...  
Keyword(s):  
Concentration Profile ◽  
Ion Beam ◽  
Error Function ◽  
Ion Beam Mixing ◽  
X Ray ◽  
Microelectronic Devices ◽  
Simple Error

ABSTRACTThis work clearly demonstrates that the X Ray Reflectometry technique (XRR), extensively used to assess the quality of microelectronic devices can be a useful tool to study the first stages of ion beam mixing. This technique allows measuring the evolution of the Si concentration profile in irradiated Cr/Si layers. From the analysis of the XRR profiles, it clearly appears that the Si profile cannot be described by a simple error function.

Ion Beam Mixing of High-Tc Superconductor Components.

1988 ◽  
Vol 128 ◽  
Author(s):  
P. Borgesen ◽  
D. A. Lilienfeld
Keyword(s):  
Ion Beam ◽  
Superconducting Thin Films ◽  
Ion Beam Mixing ◽  
High Tc ◽  
Fundamental Interest ◽  
High Tc Superconductor ◽  
Wide Range ◽  
Mixing Rates ◽  
The Individual ◽  
Binary Mixing

ABSTRACTThe design of the necessary multilayer structures for producing superconducting thin films by ion beam mixing methods requires, among others, the knowledge of the individual (binary) mixing rates. In order to measure these, various combinations of Y, Ba, Cu, and Bi were irradiated with 600 keV Xe-ions at 80K and 300K. The systems exhibited a wide range of mixing behaviors which are also of fundamental interest. Ba and Cu readily formed the BaCu phase, and further mixing with Cu progressed only via binary collision mechanisms. At 80K Cu and Y were rapidly mixed in any ratio by thermal spikes, whereas a Cu rich sample rapidly formed the Cu6Y phase at 300K. Ba could not be mixed into Y or a Y-Cu mixture. Finally, irradiation of polycrystalline layers of Cu and Bi apparently lead to rapid motion of Bi along grainboundaries at both temperatures.

The influence of hydrogen on ion beam mixing of multilayer films

1989 ◽  
Vol 4 (4) ◽  
pp. 821-833 ◽  
Author(s):  
P. B⊘rgesen ◽  
R. E. Wistrom ◽  
H. H. Johnson ◽  
D. A. Lilienfeld
Keyword(s):  
Room Temperature ◽  
Ion Beam ◽  
Liquid Nitrogen Temperature ◽  
Heat Of Mixing ◽  
Mixing Rate ◽  
Ion Beam Mixing ◽  
Thermal Spike Model ◽  
Spike Model ◽  
Mixing Rates ◽  
Lower Temperature

Previous qualitative studies of ion beam mixing of Ni–Ti and Fe–Ti multilayers at room temperature have shown the Ni–Ti samples to mix considerably faster than the Fe–Ti, in apparent contrast with theory. Furthermore, the Fe–Ti mixing was strongly inhibited by previous charging of the sample with hydrogen, whereas only a small effect was seen for Ni–Ti. We have quantified the mixing and extended the study to four more systems (Al–Ti. Co–Ti, Cu–Ti, and Pd–Ti) and lower temperatures. This allows some important conclusions to be drawn. Predictions based on a thermal spike model underestimate the larger room temperature mixing rates (Cu–Ti, Ni–Ti, and Pd–Ti), apparently because of contributions from a temperature dependent mechanism such as radiation enhanced diffusion. The lower mixing rates (Fe–Ti, Co–Ti, and Ni–Ti at ∼80 K) are overestimated by a factor of 2–3.5, possibly because of hydrogen contamination of the as-deposited samples. For the Al–Ti sample, the experimental mixing rate was in good agreement with predictions. Except for the Cu–Ti sample, results were seen to vary with heat of solution, rather than heat of mixing, suggesting significant contributions from the lower temperature after-spike regime. Hydrogen charging was found to reduce the Fe–Ti mixing rate by a factor of 7 at room temperature, whereas the Co–Ti and Ni–Ti rates were only reduced by a factor of 2, and the mixing of the Pd–Ti was influenced very little. Near liquid nitrogen temperature the Ni–Ti mixing rate was more strongly reduced (by a factor of 3–4). Our results suggest that the original hydrogen contamination in as-deposited samples may also cause significant reduction of mixing rates in some materials.

Ion Beam Mixing Effects in Au-Fe and Pt-Fe Thin Bilayers

1983 ◽  
Vol 27 ◽  
Author(s):  
G. Battaglin ◽  
A. Carnera ◽  
G. Celotti ◽  
G. Della Mea ◽  
V.N. Kulkarni ◽  
...  
Keyword(s):  
Solid Solution ◽  
Diffraction Analysis ◽  
Linear Dependence ◽  
Ion Beam ◽  
Bilayer Structure ◽  
Square Root ◽  
X Ray Diffraction ◽  
Ion Beam Mixing ◽  
X Ray ◽  
Mixing Effects

ABSTRACTMixing effects induced by Kr++ bombardment in the Au-Fe and Pt-Fe metallic systems have been studied by Rutherford backscattering and X-ray diffraction techniques. The mixed amount of Fe atoms shows a linear dependence on the square root of the Kr do se for both systems. The induced mixing appears more efficient for the Pt-Fe with respect to the Au-Fe system. In the case of Pt-Fe mixing is much more efficient when the initial bilayer structure has Pt on the top. The X-ray diffraction analysis reveals the formation of an extended solid solution of Fe in Pt, having the Fe40 Pt60 composition.

Thin-film alloys of Bi1−x Sbx produced by ion-beam mixing and their thermoelectric properties

1987 ◽  
Vol 2 (3) ◽  
pp. 313-316 ◽  
Author(s):  
A. M. Ibrahim ◽  
D. A. Thompson ◽  
J. A. Davies
Keyword(s):  
Thin Film ◽  
Thermoelectric Power ◽  
Alloy Composition ◽  
Ion Beam ◽  
Atomic Displacement ◽  
Square Root ◽  
Ion Beam Mixing ◽  
Maximum Value ◽  
Higher Doses ◽  
Backscattering Analysis

Ion-beam mixing in the Bi/Sb system using Ne+, Ar+, and Kr+ ions in the energy range 40–110 keV has been investigated by Rutherford backscattering analysis. The mixing is shown to be temperature independent in the region of 40–250 K; at higher temperatures the mixing per ion increases rapidly with temperature. Initially, a square-root dependence of the mixing on the ion dose was observed. At higher doses a saturation effect is obtained as the Sb becomes uniformly distributed in depth throughout the film. Also, the mixing was found to increase linearly with the energy deposited into atomic displacement collisions at the Bi/Sb interface. Alloys of Bi1−x Sbx (0<x<0.5) have been produced. The thermoelectric power of the fully mixed alloys reaches a maximum value at an alloy composition of Bi0.87 Sb0.13. The thermoelectric power for partially mixed alloys exhibits almost the same dependence on Ar+ dose as the amount of mixing.

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