The Effect of Thermal Spike on the Ion Irradiation Induced Grain Growth

1991 ◽  
Vol 235 ◽  
Author(s):  
K. H. Chae ◽  
J. H. Song ◽  
J. H. Joo ◽  
J. J. Woo ◽  
C. N. Whang ◽  
...  
Keyword(s):  
Grain Growth ◽  
Low Dose ◽  
Ion Irradiation ◽  
Ion Beam ◽  
Heat Of Mixing ◽  
High Dose ◽  
Thermal Spike ◽  
Close Relationship ◽  
Basic Parameters ◽  
Good Agreement

ABSTRACTThe relation between the ion irradiation induced grain growth in bilayer system and the basic parameters involved in ion beam mixing process was studied. TEM micrographs showed that a significant grain growth has been induced by Ar+ irradiation at room temperature. The grain size increases rapidly in low dose region, while it approaches a saturated value in high dose region, and it has close relationship with thermodynamic properties such as cohesive energy ( ΔHc ) and heat of mixing( ΔHm ). The experimental results are in good agreement with the model for the grain growth based on the thermal spike induced atomic migration.

Ion Irradiation Induced Grain Growth in Metal Thin Films

1988 ◽  
Vol 100 ◽  
Author(s):  
Joyce. C. Liu ◽  
J. W. Mayer
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Grain Growth ◽  
Material Properties ◽  
Low Dose ◽  
Ion Irradiation ◽  
High Dose ◽  
Atomic Mobility ◽  
Metal Thin Films ◽  
Dose Regime

ABSTRACTThe dependence of ion irradiation induced grain growth on collision and material properties were studied in metal and alloy thin films. The uniform grain size increased with ion dose in the low dose regime; and the growth saturated in the high dose regime. The saturated grain size was determined 'by the cascade dimension as well as the atomic mobility. The growth was further influenced by the temperature, composition and impurity.

scholarly journals Ion Beam Enhanced Grain Growth in Thin Films

1986 ◽  
Vol 74 ◽  
Author(s):  
Harry A. Atwater ◽  
Carl V. Tiiompson ◽  
Henry I. Smith
Keyword(s):  
Thin Films ◽  
Growth Rate ◽  
Grain Boundary ◽  
Grain Growth ◽  
Thermal Equilibrium ◽  
Ion Beam ◽  
Defect Concentration ◽  
Growth Enhancement ◽  
Frenkel Defect ◽  
Good Agreement

AbstractIon beam enhanced grain growth has been investigated in thin films of Ge. Grain boundary mobilities are greatly enhanced over their thermal equilibrium values and exhibit a very weak temperature dependence. We propose that defects which are generated by the ion beam at or near the grain boundary are responsible for the boundary mobility enhancement. Films of Ge deposited under different conditions, either unsupported or on thermally oxidized Si, exhibit similar normal grain growth enhancement when implanted with 50 keV Ge+. Beam-enhanced grain growth in Ge was also demonstrated using Xe+, Kr+, and Ar+ ions. The variation in growth enhancement with projectile ion mass is in good agreement with the enhanced Frenkel defect population calculated using a modified Kinchin-Pease formula and Monte Carlo simulation of ion transport in thin films. Calculations based on experiments suggest that there is approximately one atomic jump across the grain boundary per defect generated. Also, the grain growth rate for a given beam-generated defect concentration near the boundary is approximately equal to the expected growth rate for the same defect concentration if thermally generated.

Radiation-Induced Nanostructures in an Iron Phosphate Glass

2003 ◽  
Vol 792 ◽  
Author(s):  
K. Sun ◽  
T. Ding ◽  
L.M. Wang ◽  
R.C. Ewing
Keyword(s):  
Phosphate Glass ◽  
Ion Irradiation ◽  
Ion Beam ◽  
Dose Range ◽  
Iron Phosphate ◽  
High Energy ◽  
High Dose ◽  
Beam Irradiation ◽  
Ion Beam Irradiation ◽  
Feo Nanoparticles

ABSTRACTElectron and ion irradiation-induced nanostructures in an iron phosphate glass with a composition of 45 mol%Fe2O3-55 mol%P2O5 have been characterized by advanced electron microbeam techniques. Analysis by energy-filtered transmission electron microscopy indicated that Fe-rich and P-rich nanophases were formed when the glass was irradiated under a broad (with a diameter of 1.2μm) electron beam [give the dose range]. Phase separation developed with the increase in electron dose (from 1.0×1026e/m2 to 4.8×1026e/m2) as a result of the formation of an Fe-rich phase and pure P-phase. The formation of the Fe-rich and the P-phases are thought to be due to mainly ionization process. Under a low energy ion beam irradiation, Fe/FeO nanoparticles were formed, as confirmed by selected-area electron diffraction analysis. However, no nanoparticles were observed under a high-energy high-dose ion irradiation. The ion beam-irradiation results suggest that the formation of the Fe/FeO nanoparticles was due to preferential sputtering during ion irradiation and that the nanoparticles lie within the surface layers of the glass.

scholarly journals Nano-structuring, surface and bulk modification with a focused helium ion beam

2012 ◽  
Vol 3 ◽  
pp. 579-585 ◽  
Author(s):  
Daniel Fox ◽  
Yanhui Chen ◽  
Colm C Faulkner ◽  
Hongzhou Zhang
Keyword(s):  
Ion Irradiation ◽  
Ion Beam ◽  
High Dose ◽  
Modification Process ◽  
Dose Irradiation ◽  
Probe Size ◽  
Helium Ion ◽  
High Incidence ◽  
High Level ◽  
Irradiation Process

We investigate the ability of a focused helium ion beam to selectively modify and mill materials. The sub nanometer probe size of the helium ion microscope used provides lateral control not previously available for helium ion irradiation experiments. At high incidence angles the helium ions were found to remove surface material from a silicon lamella leaving the subsurface structure intact for further analysis. Surface roughness and contaminants were both reduced by the irradiation process. Fabrication is also realized with a high level of patterning acuity. Implantation of helium beneath the surface of the sample is visualized in cross section allowing direct observation of the extended effects of high dose irradiation. The effect of the irradiation on the crystal structure of the material is presented. Applications of the sample modification process are presented and further prospects discussed.

scholarly journals Evaluation of Radiation Response in CoCrFeCuNi High-Entropy Alloys

Entropy ◽  
2018 ◽  
Vol 20 (11) ◽  
pp. 835 ◽  
Author(s):  
Yang Wang ◽  
Kun Zhang ◽  
Yihui Feng ◽  
Yansen Li ◽  
Weiqi Tang ◽  
...  
Keyword(s):  
Ion Irradiation ◽  
Ion Beam ◽  
High Entropy Alloys ◽  
X Ray Diffraction ◽  
Thermal Spike ◽  
High Entropy ◽  
Arc Melting ◽  
The Matrix ◽  
Volume Swelling

CoCrFeCuNi high-entropy alloys (HEAs) prepared by arc melting were irradiated with a 100 keV He+ ion beam. Volume swelling and hardening induced by irradiation were evaluated. When the dose reached 5.0 × 1017 ions/cm2, the Cu-rich phases exhibited more severe volume swelling compared with the matrix phases. This result indicated that the Cu-rich phases were favorable sites for the nucleation and gathering of He bubbles. X-ray diffraction indicated that all diffraction peak intensities decreased regularly. This reduction suggested loosening of the irradiated layer, thereby reducing crystallinity, under He+ ion irradiation. The Nix-Gao model was used to fit the measured hardness in order to obtain a hardness value H0 that excludes the indentation size effect. At ion doses of 2.5 × 1017 ions/cm2 and 5.0 × 1017 ions/cm2, the HEAs showed obvious hardening, which could be attributed to the formation of large amounts of irradiation defects. At the ion dose of 1.0 × 1018 ions/cm2, hardening was reduced, owing to the exfoliation of the original irradiation layer, combined with recovery induced by long-term thermal spike. This study is important to explore the potential uses of HEAs under extreme irradiation conditions.

Effects of High-Energy Carbon Ion Irradiation on Isatis Indigotica Fort

2011 ◽  
Vol 317-319 ◽  
pp. 2056-2062 ◽  
Author(s):  
Guang Liang Shi ◽  
Xue Hong Wang ◽  
Kai Guo ◽  
Zhao Zhou Li ◽  
Xiao Yan Hu ◽  
...  
Keyword(s):  
Soluble Protein ◽  
Selective Breeding ◽  
Ion Irradiation ◽  
Ion Beam ◽  
High Energy ◽  
Total Soluble Protein ◽  
High Dose ◽  
Isatis Indigotica ◽  
Carbon Ion ◽  
Different Doses

The aim of this study was to provide a theoretical basis for a high-energy carbon ion irradiation process for inducing mutations for selective breeding in Isatis indigotica Fort. The experiments were designed to evaluate the effects of different doses of high-energy 12C6+ ions (10-140 Gy) on physiological changes in I. indigotica seedlings. Dry seeds of I. indigotica were irradiated using different doses of 270 MeV energy 12C6+ ion beam, and the response of the subsequent seedlings was monitored using well-established indexes of physiological characteristics. Results showed that optimum results were achieved with a high-dose 12C6+ ion beam at 35 Gy where the activities of superoxide dismutase (SOD) and catalase (CAT) were enhanced. However, excessive irradiation reduced the activities of SOD and CAT. As the dose increased, the activity of peroxidase increased initially and then decreased compared with controls that were not irradiated (0 Gy). The content of malondialdehyde first decreased and then increased with the treatment. Total soluble protein content initially increased and then decreased with increasing doses of radiation; the proline content improved sharply compared to the control. The results of this study suggest that that a low dose of 12C6+ ion beam could enhance the activities of protective enzymes and the levels of proline and soluble protein, and that a dose range of 35–60 Gy is likely to be optimum for inducing useful mutations in I. indigotica for a stable selective breeding program.

Helium Ion Beam Induced Arsenic Atom Displacement Studied by Medium-Energy Ion Spectroscopy

1993 ◽  
Vol 316 ◽  
Author(s):  
Shin Yokoyama ◽  
Zbigniew J. Radzimski ◽  
Kensaku Ishibashi ◽  
Takeshi Watanabe ◽  
Masataka Hirose
Keyword(s):  
Low Dose ◽  
Ion Beam ◽  
High Dose ◽  
Medium Energy ◽  
Arsenic Atom ◽  
Ion Beam Irradiation ◽  
Nuclear Stopping ◽  
Ion Spectroscopy ◽  
Helium Ion ◽  
Atom Displacement

ABSTRACTAn arsenic atom displacement in As+ ion implanted Si induced by He+ ion beam irradiation has been studied by medium-energy (175keV) ion spectroscopy (MEIS). The He+ energy and dose dependences of the displaced arsenic atoms have been examined in the range of 30-175keV and ≤6×10-4C/cm2, respectively. The amount of the displaced arsenic atoms are found to be proportional to the dose and inversely proportional to the nuclear stopping power in the low-dose region, while it saturates at high-dose region. The dose-proportional region is composed of two different proportional coefficient segments.

Ion-beam induced disordering and onset of amorphization in spinel by defect accumulation

1995 ◽  
Vol 10 (4) ◽  
pp. 981-985 ◽  
Author(s):  
N. Bordes ◽  
L.M. Wang ◽  
R.C. Ewing ◽  
K.E. Sickafus
Keyword(s):  
Ion Irradiation ◽  
Ion Beam ◽  
Crystalline Material ◽  
High Dose ◽  
Transmission Electron ◽  
Defect Accumulation ◽  
Radiation Resistant ◽  
Crystalline Domains ◽  
Resistant Ceramic

Ion-irradiation induces amorphization in many intermetallics and ceramics, but spinel (MgAl2O4) is considered a “radiation resistant” ceramic. Spinel was irradiated with 1.5 MeV Kr+ at 20 K and observed in situ by transmission electron microscopy (TEM). The spinel remained crystalline to a high dose of 1 × 1016 ions/cm2, without any evidence of amorphization. Another spinel was preimplanted with Ne (400 keV and 50 keV). The microstructure revealed a still crystalline material with 8 nm interstitial loops. After irradiation with 1.5 MeV Kr+ (20 K), amorphization, a result of cation disordering, initiated at a dose of 1.7 × 1015 ions/cm2. At a dose of 1 × 1016 ions/cm2, the spinel was partially amorphous and the remaining crystalline domains disordered. These results show that spinel can be disordered and that amorphization can be triggered by the introduction of stable defects, followed by ion irradiation at low temperature.

scholarly journals Thermal Spike Model of Ion-Induced Grain Growth

1990 ◽  
Vol 202 ◽  
Author(s):  
Dale E. Alexander ◽  
Gary S. Was
Keyword(s):  
Grain Boundary ◽  
Grain Growth ◽  
Ion Irradiation ◽  
Recoil Energy ◽  
Thermal Spike ◽  
Grain Boundary Mobility ◽  
Thermal Spike Model ◽  
Spike Model ◽  
Model Predictions ◽  
Boundary Curvature

ABSTRACTA thermal spike model has been developed to describe the phenomenon of ion irradiation-induced grain growth in metal alloy thin films. In single phase films where the driving force for grain growth is the reduction of grain boundary curvature, the model shows that ion-induced grain boundary mobility, Mion, is proportional to the quantity FD2/ΔHcoh3, where FD is the ion and recoil energy deposited in nuclear interactions and ΔHcoh is the cohesive energy of the element or alloy. Experimental grain growth results from ion irradiated coevaporated binary alloy films compare favorably with model predictions.

Irradiation-induced grain growth in gold and copper: In situ HVEM studies at 75-300 K

1989 ◽  
Vol 47 ◽  
pp. 644-645
Author(s):  
Charles W. Allen
Keyword(s):  
Grain Growth ◽  
Ion Irradiation ◽  
Boundary Migration ◽  
Ion Beam ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
Average Grain Size ◽  
Growth Phenomenon ◽  
In Situ Experiments

When thin polycrystalline films of Au, Cu and various other materials are subjected to energetic ion irradiation, the average grain size increases even at cryogenic temperatures. As is the case with many ion beam processes, this phenomenon of ion irradiation induced grain growth exhibits only a very mild temperature dependence. This contribution is based on in situ experiments, performed at the HVEM-Tandem User Facility at Argonne National Laboratory. This Facility interfaces a 2 MV Tandem ion accelerator and a 0.6 MV ion implanter to a 1.2 MV AEI high voltage electron microscope, which allows a wide variety of in situ ion beam experiments to be performed with simultaneous irradiation and electron microscopy or diffraction. A series of in situ ion and/or electron irradiation experiments is being performed at the HVEM-Tandem Facility at Argonne which have shown clearly for fine grained Au films that two mechanisms for growth are operative for the ion beam case: grain boundary migration as in normal thermal grain growth and grain coalescence which is similar in appearance to recrystallization by subgrain coalescence. Especially in the case of Au for which ion-induced growth is relatively rapid, such in situ experiments also demonstrate the importance of dislocation activity which is a consequence of the collision cascade damage associated with ion irradiation. Existing theories for irradiation-induced grain growth assume that growth occurs by boundary migration and that only point defects generated at grain boundaries are responsible for the growth phenomenon.

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