Inert gas diffusion and radiation damage in ionic crystals and sinters following ion bombardment

1968 ◽  
Vol 46 (6) ◽  
pp. 621-634 ◽  
Author(s):  
Hj. Matzke
Keyword(s):  
Radiation Damage ◽  
Diffusion Mechanism ◽  
Ion Bombardment ◽  
Gas Diffusion ◽  
Absolute Temperature ◽  
Diffraction Measurement ◽  
Ionic Crystals ◽  
Rare Gases ◽  
Self Diffusion ◽  
Diffusion Phenomena

A review is given of radiation damage and diffusion phenomena in a large variety of ionic crystals (oxides and halides) and two metals following ion bombardment. Ion beams of both light and heavy nuclides between mass number 3 (tritium) and 222 (emanation) were employed. The ion doses varied between 104 and 1017 ions/cm2. Four different experimental techniques were used to detect gross structural radiation damage following bombardment: reflection electron diffraction, measurement of ranges or penetration profiles, electron microscopy in transmission or using replica techniques, and gas release measurements at low temperatures. In general, materials having cubic lattice structures were shown to be more stable than anisotropic substances.Minor local damage (such as point defects, defect clusters or voids, dislocations and loops) was studied by its interaction with rare gases or other volatile elements (Br, Rb, Cs). For the heavy rare gases (Kr, Xe, Em) and low bombardment doses, volume diffusion was observed starting between 0.4 and 0.5 of the melting point, Tm, on the absolute temperature scale. The activation enthalpies ΔH were about 80 ± 10% of those for the self-diffusion of the less mobile lattice ions and were related to Tm via ΔH = (1.4 ± 0.2) × 10−3Tm eV = (32 ± 4) Tm kcal/mole. For the diffusion mechanism, a relation with self-diffusion is suggested, the gas most probably migrating in small vacancy clusters.

Berechnung von Aktivierungsenergien für die Edelgasdiffusion in α- bzw. β-CsCl

1973 ◽  
Vol 28 (2) ◽  
pp. 311-313 ◽  
Author(s):  
M. Müller ◽  
M. J. Norgett
Keyword(s):  
Diffusion Mechanism ◽  
Gas Diffusion ◽  
Rare Gases ◽  
Vacancy Pair ◽  
Two Phases

Experiments had shown that different rare gases have the same mobility in α-CsCl but not in β-CsCl. Therefore, it may be that there is a different diffusion mechanism in the two phases.Calculations show that the gas atom migrates as an interstitial in β-CsCl and that in α-CsCl, gas diffusion occurs together with the motion of a vacancy pair.

THE EFFECT OF CRYSTALLINITY AND BOMBARDMENT DOSE ON THE PENETRATION OF 40-keV XENON IONS IN IONIC CRYSTALS AND CERAMICS

1966 ◽  
Vol 44 (11) ◽  
pp. 2905-2914 ◽  
Author(s):  
J. L. Whitton ◽  
Hj. Matzke
Keyword(s):  
Radiation Damage ◽  
Single Crystals ◽  
Penetration Depth ◽  
Incident Beam ◽  
Ion Bombardment ◽  
Fused Silica ◽  
Ionic Crystals ◽  
Chemical Dissolution ◽  
Metal Single Crystals ◽  
Oriented Parallel

The range and depth distributions of 40-keV xenon ions in single crystals of NaCl, KBr, MgO, SiO2 (α quartz), in sintered UO2 and in fused silica, have been measured by the sectioning techniques of vibratory polishing and chemical dissolution. Channeling is observed in the single crystals when the [Formula: see text] is oriented parallel to the incident beam of the ions. This effect is similar to that previously reported for some metal single crystals. High bombardment doses produce a factor of 2–5 decrease in penetration depth in MgO and SiO2, materials which are known to be damaged by ion bombardment. This decrease is smaller in materials that do not show gross ion bombardment damage, such as NaCl, KBr, and UO2. Thus, the study of ranges is shown to be another means of detecting gross radiation damage.

Diffusion of Krypton in Cesium and Rubidium Iodide; A Comparison of Results Obtained Following Reactor Irradiation and Ion Bombardment

1970 ◽  
Vol 25 (2) ◽  
pp. 252-256
Author(s):  
Hj. Matzke ◽  
F. Springer
Keyword(s):  
Melting Point ◽  
Diffusion Coefficients ◽  
Ion Bombardment ◽  
Gas Diffusion ◽  
Rare Gas ◽  
Reactor Irradiation ◽  
Rare Gases ◽  
Gas Concentration ◽  
Comparison Of Results ◽  
Empirical Rule

Abstract The present study shows that under suitably chosen conditions, the same results of rare gas diffusion coefficients can be obtained in samples which are reactor irradiated to produce a homo-geneous concentration of rare gas, and in samples that are labeled with rare gas by controlled ion bombardment. In the present study, the diffusion of krypton in Rbl and Csl was found to follow the empirical rule of yielding activation enthalpies in the range (1.4±0.2) x 10-3 Tm eV, with Tm = melting point in °K. Trapping of rare gases (gas-gas or gas-damage interactions) was observed at high gas concentration.

Direct determination of the self-diffusion mechanism in bccβ-titanium

1989 ◽  
Vol 39 (8) ◽  
pp. 5025-5034 ◽  
Author(s):  
G. Vogl ◽  
W. Petry ◽  
Th. Flottmann ◽  
A. Heiming
Keyword(s):  
Diffusion Mechanism ◽  
Direct Determination ◽  
The Self ◽  
Self Diffusion

Structural and Mechanical Properties of Nanophase Ni: A Molecular-Dynamics Study of the Influence of Grain-Boundary Structure on Elastic and Plastic Behavior

1997 ◽  
Vol 492 ◽  
Author(s):  
H. Van Swygenhoven ◽  
M. Spaczér ◽  
A. Caro
Keyword(s):  
Molecular Dynamics ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Diffusion Mechanism ◽  
Distribution Functions ◽  
Boundary Structure ◽  
Plastic Behavior ◽  
Self Diffusion ◽  
Common Neighbour ◽  
Grain Boundary Structure

ABSTRACTMolecular dynamics computer simulations of high load plastic deformation at temperatures up to 500K of Ni nanophase samples with mean grain size of 5 nm are reported. Two types of samples are considered: a polycrystal nucleated from different seeds, each having random location and random orientation, representing a sample with mainly high angle grain boundaries, and polycrystals with seeds located at the same places as before, but with a limited missorientation representing samples with mainly low angle grain boundaries. The structure of the grain boundaries is studied by means of pair distribution functions, coordination number, atom energetics, and common neighbour analysis. Plastic behaviour is interpreted in terms of grain-boundary viscosity, controlled by a self diffusion mechanism at the disordered interface activated by thermal energy and stress.

Diffusion of ion-implanted Boron and Silicon in Germanium

2004 ◽  
Vol 809 ◽  
Author(s):  
Suresh Uppal ◽  
A. F. W. Willoughby ◽  
J. M. Bonar ◽  
N. E. B. cowern ◽  
R. J. H. Morris ◽  
...  
Keyword(s):  
Activation Energy ◽  
High Resolution ◽  
Diffusion Coefficients ◽  
Doping Concentration ◽  
Diffusion Mechanism ◽  
Concentration Profiles ◽  
Furnace Annealing ◽  
Temperature Range ◽  
Self Diffusion ◽  
Secondary Ion

ABSTRACTThe diffusion of B and Si in Ge is studied using implantation doping. Concentration profiles after furnace annealing in the temperature range 800–900 °C were obtained using high resolution secondary ion mass spectroscopy (SIMS). Diffusion coefficients are calculated by fitting the annealed profiles. For B, we obtain diRusivity values which are two orders of magnitude slower than previously reported in literature. An activation energy of 4.65(±0.3) eV is calculated for B diffusion in Ge. The results suggest that diffusion mechanism other than vacancy should be considered for B diffusion in Ge. For Si diffusion in Ge, the diffusivity values calculated in the temperature range 750–875 °C are in agreement with previous work. The activation energy of 3.2(±0.3) eV for Si diffusion is closer to that for Ge self-diffusion which suggests that Si diffusion in Ge occurs via the same mechanism as in Ge self-diffusion.

Sign in / Sign up

Export Citation Format

Share Document