scholarly journals Ion Mixing of Ti/C and Fe/C Bilayers

1987 ◽  
Vol 93 ◽  
Author(s):  
M. Nastasi ◽  
J. R. Tesmer ◽  
J.-P. Hirvonen
Keyword(s):  
Thermodynamic Model ◽  
Ion Beam ◽  
Diffusion Mechanism ◽  
Temperature Dependent ◽  
Enhanced Diffusion ◽  
Radiation Enhanced Diffusion ◽  
Mixing Regime

ABSTRACTBilayer samples of Ti/C and Fe/C have been ion beam mixed with 400 keV Xe ions to a dose of 1 × 1016 ions/cm2. Mixing experiments were performed at 77, 300, 573, and 723 K. The transition between the temperature independent and temperature dependent mixing occurred between 300 and 573 K in Fe/C samples and between 573 and 723 in Ti/C sample. In the temperature independent mixing regime mixing is reasonably well explained by a thermodynamic model of ion mixing while at higher temperatures a radiation enhanced diffusion mechanism is evident.

Solid-state amorphization, interdiffusion, and ion-beam mixing in Au/Zr and Ni/Zr

1989 ◽  
Vol 4 (6) ◽  
pp. 1444-1449 ◽  
Author(s):  
Fu-Rong Ding ◽  
P. R. Okamoto ◽  
L. E. Rehn
Keyword(s):  
Solid State ◽  
Ion Beam ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
Ion Beam Mixing ◽  
Enhanced Diffusion ◽  
Bilayer Films ◽  
Voltage Electron ◽  
Radiation Enhanced Diffusion

Inert-gas markers, Rutherford backscattering, and x-ray diffraction were used to investigate solid-state interdiffusion in Ni/Zr and Au/Zr bilayer films as a function of temperature; microstructural studies during annealing were performed in situ, in a high-voltage electron microscope. Au, in contrast to Ni, is not an anomalously fast diffuser in crystalline Zr. Nevertheless, an amorphous product phase was found in both alloy systems for reaction temperatures  550 K; heterogeneous nucleation of the amorphous phase was observed in Au/Zr. The interdiffusion data reveal two distinct Arrhenius regimes, 330–∼470 K and ∼480–550 K, with quite different apparent activation enthalpies. These thermal interdiffusion results are compared with temperature dependent studies of ion-beam mixing in similar bilayer specimens. This comparison indicates that the enhanced efficiencies observed for ion-beam mixing above ∼480 K result from the as-prepared metastable microstructurc, and are not due to radiation-enhanced diffusion.

Ion beam mixing and radiation-enhanced diffusion in metallic glasses

1988 ◽  
Vol 140 ◽  
pp. 267-275 ◽  
Author(s):  
R.S. Averback ◽  
H. Hahn ◽  
Fu-Rong Ding
Keyword(s):  
Metallic Glasses ◽  
Ion Beam ◽  
Ion Beam Mixing ◽  
Enhanced Diffusion ◽  
Radiation Enhanced Diffusion

Temperature-dependent radiation-enhanced diffusion in ion-bombarded solids

1988 ◽  
Vol 61 (23) ◽  
pp. 2697-2700 ◽  
Author(s):  
D. Marton ◽  
J. Fine ◽  
G. P. Chambers
Keyword(s):  
Temperature Dependent ◽  
Enhanced Diffusion ◽  
Radiation Enhanced Diffusion

Atomic Transport in Irradiated Solids

1993 ◽  
Vol 311 ◽  
Author(s):  
R.R. Averback ◽  
Mai Ghaly ◽  
Y.Y. Lee ◽  
H. Zhu
Keyword(s):  
Ion Beam ◽  
Rapid Quenching ◽  
Primary Role ◽  
Melting Points ◽  
Crystalline Materials ◽  
Enhanced Diffusion ◽  
Atomic Transport ◽  
Radiation Enhanced Diffusion ◽  
Radiation Induced ◽  
Kinetics Of

ABSTRACTAtomic transport in irradiated solids has been investigated in both the prompt and delayed regimes. Prompt effects are revealed on an atomic level through molecular dynamics computer simulations. It is demonstrated that for metals like gold, which have high atomic numbers and low melting points, thermal spikes play a primary role in the cascade dynamics and that concepts like melting and rapid quenching are useful descriptions. Surface effects in these metals are also discussed. For metals with higher melting points and lower atomic numbers, the cascade dynamics are determined almost exclusively by energetic collisions far above thermal energies. This is illustrated by simulations of cascades in NiAl. The effect of the high ordering energy in this intermetallic compound on the radiation-induced defect structure has also been studied.Atomic transport in the delayed regime is illustrated by two examples: an order-disorder alloy, Cu3Au, and an amorphous alloy, NiZr. The first example is used to illustrate various aspects of radiation enhanced diffusion (RED): ion beam mixing, diffusion kinetics, the effects of primary recoil spectrum, and the importance of chemical order. The second example illustrates that the basic theory of RED, which was developed to describe crystalline materials, appears to work adequately for amorphous metal alloys, suggesting that similar mechanisms may be operating. It is shown, however, that the kinetics of RED observed in amorphous alloys are not unique to point defect models.

scholarly journals Analysis of Experiments in Helium Microbeam Mixing

1991 ◽  
Vol 235 ◽  
Author(s):  
John B. Davis ◽  
R. E. Benenson ◽  
David Peak
Keyword(s):  
Dose Rate ◽  
Ion Beam ◽  
Liquid Nitrogen Temperature ◽  
Enhanced Diffusion ◽  
Interface Width ◽  
Interface Growth ◽  
Radiation Enhanced Diffusion ◽  
Order Of Magnitude ◽  
Constant Dose ◽  
Diffusion Of Vacancies

ABSTRACTWe have continued to investigate ion-beam mixing in bilay-er targets irradiated by 2-MeV He+ microbeams at room temperature. Although we have previously reported a linear dependence of interface width on dose for Cu/Al targets 1, more extensive results have not supported this conclusion, within statistical uncertainty, it appears that the interface width in Cu/Al (1) is proportional to the square root of dose, at constant dose rate, (2) is larger in Al than in Cu, for the same dose, (3) is proportional to the 1/4 power of dose rate, and (4) is absent at liquid nitrogen temperature. Calculations of the expected interface growth rate from a radiation-enhanced diffusion model have provided order-of-magnitude agreement with observed rates. Additionally, intermixing of Cu and Al outside the damaged area may indicate significant transverse diffusion of vacancies.

Radiation Enhanced Diffusion in Ion-Implanted Glasses and Glass/Metal Couples

1983 ◽  
Vol 27 ◽  
Author(s):  
G. W. Arnold
Keyword(s):  
Rutherford Backscattering Spectrometry ◽  
Diffusion Mechanism ◽  
Glass Network ◽  
Heavy Ion ◽  
Rutherford Backscattering ◽  
Enhanced Diffusion ◽  
Mixed Alkali ◽  
Radiation Enhanced Diffusion ◽  
Glass Metal ◽  
Ion Implanted

ABSTRACTIon implantation causes alkali migration to the surface in alkali silicate glasses. Rutherford backscattering spectrometry was used to follow this depletion. Room temperature implantations of 5×1016 250 keV Xe/cm2 in 12M20·88SiO2 (M = Li,Na,K,Rb,Cs) removes approximately equal numbers (within a factor of 2) of alkali from the glass. Low temperature (77K) implants significantly reduce the alkali loss. These results imply a radiationenhanced diffusion mechanism in which the alkali interchanges with the products of the collision cascade, with the kinetics being limited by the radiation damage components. The results for mixed-alkali glasses ((12−x)M2O·xCs20·88Si02) give further evidence for this process. In glass/'metal couples, radiation enhanced diffusion allows the interchange of glass network components with deposited metals. Rutherford backscattering spectrometry was used to follow the interchange of silicate and phosphate glass components with metal ions near the heavy-ion implanted interface between glass substrate and metal (Al,Zr) films.

Ar+ Induced Interfacial Mixinc in the Pd/Cu Bilayer System

1989 ◽  
Vol 157 ◽  
Author(s):  
H.K. Kim ◽  
J.H. Song ◽  
S.K. Kim ◽  
K. Jeong ◽  
C.N. Whang ◽  
...  
Keyword(s):  
Room Temperature ◽  
Ion Beam ◽  
Layer By Layer ◽  
Ion Beam Mixing ◽  
Enhanced Diffusion ◽  
Bilayer System ◽  
Radiation Enhanced Diffusion

ABSTRACTIon beam mixing of a Pd/Cu bilayer is studied using irradiation with 80 keV Ar+ ions at room temperature. RBS analysis shows that intermixing has occurred across the Pd/Cu interface, and that the mixing amount increases with increasing ion dose, which agrees well with a model for radiation enhanced diffusion. It is found that the Cu3Pd phase grows in a layer-by-layer manner.

Diffusion Induced Grain Boundary Migration in Ion-Beam Mixed Fe-AL

1982 ◽  
Vol 40 ◽  
pp. 634-635 ◽  
Author(s):  
Shankara K. Prasad ◽  
Herbert Herman ◽  
Alexander H. King ◽  
Allen Goland
Keyword(s):  
Thin Film ◽  
Thin Layer ◽  
Boundary Migration ◽  
Ion Beam ◽  
Bulk Diffusion ◽  
Grain Boundary Migration ◽  
Recoil Implantation ◽  
Enhanced Diffusion ◽  
Radiation Enhanced Diffusion ◽  
Mixed Layers

Ion beam intermixing is a newly investigated process wherein an ion beam is used to induce a reaction between a deposited thin layer and the substrate. The ion beam induced intermixing and microalloying at the interface can be due to three processes: 1. Recoil implantation 2. Cascade mixing 3. Radiation enhanced diffusion. Mixing due to recoil implantation has been studied by Nelson and was shown to result in very shallow mixed layers. However, in their recent investigation of Pt-Si, Pd-Si and Al-Ge and other systems, Tsaur et.al, have observed the formation of a thick surface alloy which is metastable in nature. They attribute this intermixing of the deposited thin film and the substrate, and the eventual "epitaxial" growth, to cascade overlap and radiation enhanced bulk diffusion. The present work provides evidence for the role played by grain boundaries in both intermixing and grain growth.

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