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Showing 1 to 20 of 82 for “"ion irradiation"”.
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Nanostructure formation on Germanium by ion irradiation
This thesis work is focused on the investigation of a peculiar phenomenon observed in germanium: the formation of a regular network of columnar nanovoids induced by heavy ion and high fluence irradiation at room temperature. This phenomenon can represent a possible way to produce wide …
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Nanostructuring of Cu-TiB2 induced by ion irradiation
The stability of materials under irradiation is a critical topic and has been an area of fundamental interest in particular for materials used in nuclear reactors. These dissipative systems which exist far from equilibrium pose a challenge in understanding due to the existence of multiple dynamical …
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Atomistic Simulations of Ion Irradiation of Nanostructures for Industrial Applications
Ionisäteilytys on ollut teollisuuden puolesta merkittävän kiinnostuksen kohteena 1950-luvulta lähtien. Ionisäteet ovat nousseet käyttöön monilla aloilla johtuen niiden kyvyn muokata materiaalien ominaisuuksia hallitusti. Tärkeimpänä on ollut niiden sovellus puolijohdelaitteissa kuten diodeissa ja …
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Effects of ion irradiation on 4H- SiC p-n junction
… operating in hostile environment such as radiation rich and high temperature. Ion irradiation affects the electrical performance of different kind of 4H-SiC based devices with a subsequent increase in the electrical resistance, leakage current and with a reduction in doping concentration, …
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Dewetting and Stress Evolution in Thin Films During Ion Irradiation
This project studies the morphology evolution of non-wetting metal films on a substrate during ion irradiation. It reveals that the mobility of the solid atoms is significantly improved during irradiation and the non-wetting films can dewet as if they are melted. The ion induced dewetting process …
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Ion Irradiation Induced Roughening and Smoothing of Metal Films on Dielectric Substrates
This study investigates the morphology evolution of ultrathin Pt films on dielectric substrates produced by heavy ion bombardment. The films roughen and form nanopatterns which coarsen in a certain dose range. The microstructure evolution is characterized using AFM, SEM and RBS. The results are …
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Thermal conductivity of UO2 and U3O8 epitaxial layers damaged by ion irradiation
… uranium oxides between 90 K and 658 K. The irradiation doses range from 5x10^13 argon ions/cm² to 2x10^16 Ar+/cm² at 2 MeV and room temperature. The main focus lies on 360 – 500 nm single crystal UO2 and U3O8 thin films grown on YSZ substrates. The U3O8 samples are formed by heating the UO2 …
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Void and Helium Bubble Stability in Amorphous Silicon Subjected to Heavy Ion Irradiation
Made available in DSpace on 2017-07-06T18:55:41Z (GMT). No. of bitstreams: 3 Okuniewski_Maria_A_MS.pdf: 82892848 bytes, checksum: 0e8165f7f8e7b43f30278739ac8c88a1 (MD5) Okuniewski_Maria_A_MS_ABS.pdf: 1807599 bytes, checksum: 56e56e0bdcdb4af9e49619bba6b03555 (MD5) license.txt: 4813 bytes, checksum: …
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Effects of Xe ion irradiation of ZrN and the migration behaviour of implanted Eu
… candidate for inert matrix for transmutation of long-lived nuclear waste (plutonium and minor actinides) in fast nuclear reactors. In the nuclear reactor environment ZrN will be exposed to di erent irradiations at elevated temperatures. Under these conditions, it should retain its …
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Effect of ion irradiation on the rate dependence of plastic deformation of extruded Zr-2.5%Nb
… pressure tube material in the transverse direction. Through testing at room temperature, material properties such as the strain hardening, strain rate sensitivity and apparent activation volume were investigated. The effects of Zr+ ion-implantation occurring at 300°C, simulating …
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Microstructure Evolution of Two Model Ferritic/Martensitic Steels Under Ion Irradiation In A Transmission Electron Microscope
… and cladding components designed for Generation IV reactors because of their superior resistance to radiation damage at the high operating temperatures envisioned in these reactors. To enable the development and optimization of such advanced alloys for in-reactor use, a fundamental …
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Development of a Multiscale Atomistic Code to Investigate Self-Organized Pattern Formation Induced by Ion Irradiation
… ripples and quantum dots can be induced by ion beam sputtering (IBS). For the past decades, the understanding of such phenomenon has been mainly relied on the Bradley-Harper theory that attributes the formation of self-organized patterns to the interplay between roughening by curvature …
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Disorder and nanopatterning in ordered binary alloys: in situ ion irradiation and kinetic Monte Carlo simulation
… experimentally through in situ electron diffraction and dark-field transmission electron microscopy. Under irradiation with 500 keV Ne+ ions, our diffraction analysis reveals a similar, but steeper, trend in disordering rate as previously reported by resistivity. Further investigations by …
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Radiation-Enhanced Diffusion and Defect Production During Ion Irradiation of MgO and Al(2)O(3)
Radiation enhanced diffusion of O$\sp{18}$, Ca and Zn buried tracer layers in MBE grown MgO was measured following irradiation with either 2.0 MeV Kr or 1.0 MeV Ne, He or H from 30 to 1500$\sp\circ$C. This represents the first reported RED measurements on an oxide system. Ion beam mixing at …
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Experimental and Simulation Studies of the Processing of Nanoscale Materials: Inert Gas Condensation and Ion Irradiation Methods
Analysis of magnetization data in the framework of superparamagnetic theory revealed that at irradiation temperatures Ti below T i ∼350°C, phase separation in Cu-Co films of all compositions stabilizes at high doses (by 5 x 1015 ions/cm 2), indicating the existence of temperature-dependent …
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Determination of UO2 thin films mechanical properties under heavy ion irradiation using nanoindentation and finite element modeling
The mechanical response of UO2 to irradiation is becoming increasingly important due to the shift to higher burn-up rates in the next generation of reactors. In the current study, thin films of UO2 were deposited on YSZ substrates using reactive-gas magnetron sputtering. Nanoindentation was used to …
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Creation of Surface and Bulk Defects of Germanium and Surface Roughening of Germanium During High Energy Ion Irradiation
… at step edges, while no surface pattern formation is observed at room temperature. Also, model of Politi and Villain agrees relatively well with the roughening and coarsening of the Ge(111) surfaces etched by 5 keV Xe ions at 250°C and 275°C. At 300°C, a surface pattern is observed …
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Creation of Surface and Bulk Defects of Ge and Surface Roughening of Ge During High Energy Ion Irradiation
Submitted by Jenny Wong-Welch (wongwel2@illinois.edu) on 2011-11-10T17:26:40Z No. of bitstreams: 1 2001_kim.pdf: 5955624 bytes, checksum: 04d9d46f170c764db23bc697b9df9525 (MD5)
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Swift heavy-ion irradiation of amorphous silicon dioxide, silicon nitride and silicon oxynitrides composite systems: from ion tracks to nanoparticle shaping
This work provides a systematic study of ion irradiation to tailor the physical and chemical properties of a-SiO2, a-Si3N4 and a-SiOxNy materials with a particular focus on three specific areas: (i) the formation of ion tracks by swift heavy-ion (SHI) irradiation in a-SiO2, a-Si3N4, and a-SiOxNy, …
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Swift heavy-ion irradiation of amorphous silicon dioxide, silicon nitride and silicon oxynitrides composite systems: from ion tracks to nanoparticle shaping
This work provides a systematic study of ion irradiation to tailor the physical and chemical properties of a-SiO2, a-Si3N4 and a-SiOxNy materials with a particular focus on three specific areas: (i) the formation of ion tracks by swift heavy-ion (SHI) irradiation in a-SiO2, a-Si3N4, and a-SiOxNy, …
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