Diffusion of Au in Amorphous Si During Ion-Beam Irradiation

1988 ◽  
Vol 100 ◽  
Author(s):  
F. Priolo ◽  
J. M. Poate ◽  
D. C. Jacobson ◽  
J. Linnros ◽  
J. L. Batstone ◽  
...  
Keyword(s):  
Activation Energy ◽  
Ion Beam ◽  
Liquid Nitrogen Temperature ◽  
Ion Beam Irradiation ◽  
Arrhenius Behavior ◽  
Enhanced Diffusion ◽  
Dose Rates ◽  
Radiation Enhanced Diffusion ◽  
Amorphous Si ◽  
Temperature Radiation

ABSTRACTWe have measured the radiation-enhanced diffusion of Au in amorphous Si in the temperature range 77–700 K. Gold was implanted to depths of 500Å at concentrations of an atomic %. The samples were than amorphized to depths of -2μm using MeV Ar implants at liquid nitrogen temperature. Radiation-enhanced diffusion was induced by a 2.5 MeV Ar beam at doses of 2×1016−2×1017/cm2 and dose rates of 7×1012−7×1013/cm2sec. The diffusion coefficients show three well defined regions. At temperatures <400K diffusion is essentially athermal and due to ballistic mixing. At temperatures between 400K and 700K the diffusion, which is considerably enhanced over the usual thermal values, has an Arrhenius behavior with an activation energy of 0.37 eV. At higher temperatures thermal diffusion, with an activation energy of 1.42 eV, dominates.

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.

Exploring The Use of Pulsed Irradiations for Studying the Transient Sink Formed by Cascade Producing Radiation

1998 ◽  
Vol 540 ◽  
Author(s):  
Dale E. Alexander
Keyword(s):  
Ion Beam ◽  
Heavy Ion ◽  
Sink Strength ◽  
Beam Irradiation ◽  
Ion Beam Irradiation ◽  
Enhanced Diffusion ◽  
Diffusivity Measurements ◽  
Radiation Enhanced Diffusion ◽  
Irradiation Pulse ◽  
Pulsed Irradiation

AbstractAn approach is suggested for using pulsed irradiation experiments to study attributes of the transient sink formed by cascade producing radiation. As an example, a simple model of radiation enhanced diffusion is proposed for a dual ion beam irradiation in which one of the beams is a pulsed, sink-producing heavy ion. It is demonstrated that by combining this model with diffusivity measurements evaluated as a function of the irradiation pulse wavelength, it is possible to quantitatively determine the transient sink strength and its characteristic lifetime.

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

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.

Mechanism of Ion-Induced Solid-Phase Crystallization and Amorphization

1989 ◽  
Vol 157 ◽  
Author(s):  
T.k. chaki
Keyword(s):  
Free Energy ◽  
Low Temperatures ◽  
Solid Phase ◽  
Amorphous Solid ◽  
Crystalline Solid ◽  
Enhanced Diffusion ◽  
Dose Rates ◽  
A Value ◽  
Radiation Enhanced Diffusion ◽  
High Irradiation Dose

ABSTRACTA mechanism is proposed to explain ion-induced solid-phase epitaxial growth (SPEG). It is argued that radiation-enhanced diffusion in amorphous solid is the cause of ion-induced SPEG at relatively low temperatures. The atoms in the amorphous solid near the crystalline/amorphous interface adjust their positions to lattice sites due to a free energy decrease associated with the transformation from amorphous to crystalline solid. An expression for the velocity of ion-induced SPEG is derived. At low temperatures and high irradiation dose rates, a large number of atoms in the lattice gets displaced and the free energy of the crystalline solid can increase to such a value that the crystalline/amorphous interface may remain stationary. It is shown that the dose rate at which the interface remains stationary increases with the temperature, following an Arrhenius dependence.

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