scholarly journals Comprehensive Understanding of Hillocks and Ion Tracks in Ceramics Irradiated with Swift Heavy Ions

2020 ◽  
Vol 4 (4) ◽  
pp. 43
Author(s):  
Norito Ishikawa ◽  
Tomitsugu Taguchi ◽  
Hiroaki Ogawa
Keyword(s):  
Heavy Ions ◽  
Ion Irradiation ◽  
Incidence Angle ◽  
Recrystallization Process ◽  
Comprehensive Understanding ◽  
Ion Tracks ◽  
Swift Heavy Ions ◽  
Transmission Electron ◽  
Niobium Doped ◽  
Track Diameter

Amorphizable ceramics (LiNbO3, ZrSiO4, and Gd3Ga5O12) were irradiated with 200 MeV Au ions at an oblique incidence angle, and the as-irradiated samples were observed by transmission electron microscopy (TEM). Ion tracks in amorphizable ceramics are confirmed to be homogenous along the ion paths. Magnified TEM images show the formation of bell-shaped hillocks. The ion track diameter and hillock diameter are similar for all the amorphizable ceramics, while there is a tendency for the hillocks to be slightly bigger than the ion tracks. For SrTiO3 (STO) and 0.5 wt% niobium-doped STO (Nb-STO), whose hillock formation has not been fully explored, 200 MeV Au ion irradiation and TEM observation were also performed. The ion track diameters in these materials are found to be markedly smaller than the hillock diameters. The ion tracks in these materials exhibit inhomogeneity, which is similar to that reported for non-amorphizable ceramics. On the other hand, the hillocks appear to be amorphous, and the amorphous feature is in contrast to the crystalline feature of hillocks observed in non-amorphizable ceramics. No marked difference is recognized between the nanostructures in STO and those in Nb-STO. The material dependence of the nanostructure formation is explained in terms of the intricate recrystallization process.

scholarly journals C60 ions of 1 MeV are slow but elongate nanoparticles like swift heavy ions of hundreds MeV

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
H. Amekura ◽  
K. Narumi ◽  
A. Chiba ◽  
Y. Hirano ◽  
K. Yamada ◽  
...  
Keyword(s):  
Heavy Ions ◽  
Ion Source ◽  
Synergy Effect ◽  
Irradiation Effects ◽  
Nuclear Collisions ◽  
Ion Tracks ◽  
Swift Heavy Ions ◽  
New Type ◽  
Molecule Model ◽  
Track Diameter

Abstract This study reports that high fluence fullerene ion (C60+) irradiation of 1–6 MeV, which was made possible by a new-type of high-flux ion source, elongates metal nanoparticles (NPs) in amorphous SiO2 as efficiently as swift heavy ions (SHIs) of 200 MeV Xe14+, i.e., two orders of the magnitude higher energy ions. Comparing the irradiation effects induced by both the beams, the stopping processes of C60 ions in SiO2 are discussed in this paper. Despite of having almost the same elongation efficiency, the C60+ irradiation induced ~10 times more efficient sputtering due to the clustering enhancement and/or the synergy effect. Ion tracks of ~10.4 nm in diameter and 60–80 nm in length were observed in crystalline SiO2 under 4 MeV C60 irradiation. While the track diameter was comparable to those by SHIs of the same electronic stopping, much shorter track lengths than those predicted by a rigid C60 molecule model indicates that the fragmentation occurred due to nuclear collisions. The elongation of the metal NPs was induced only down to the depth where the tracks were observed but not beyond.

Single-ion tracks inGd2Zr2−xTixO7pyrochlores irradiated with swift heavy ions

2009 ◽  
Vol 79 (22) ◽  
Author(s):  
Maik Lang ◽  
Jie Lian ◽  
Jiaming Zhang ◽  
Fuxiang Zhang ◽  
William J. Weber ◽  
...  
Keyword(s):  
Heavy Ions ◽  
Ion Tracks ◽  
Swift Heavy Ions

TEM analysis of ion tracks and hillocks produced by swift heavy ions of different velocities in Y3Fe5O12

2020 ◽  
Vol 127 (5) ◽  
pp. 055902 ◽  
Author(s):  
N. Ishikawa ◽  
T. Taguchi ◽  
A. Kitamura ◽  
G. Szenes ◽  
M. E. Toimil-Molares ◽  
...  
Keyword(s):  
Heavy Ions ◽  
Tem Analysis ◽  
Ion Tracks ◽  
Swift Heavy Ions

Microstructure of Swift Heavyion Irradiated MgAl204 Spinel

1998 ◽  
Vol 540 ◽  
Author(s):  
S.J. Zinkle ◽  
Hj. Matzke ◽  
V.A. Skuratov
Keyword(s):  
Heavy Ions ◽  
Room Temperature ◽  
Heavy Ion ◽  
Elastic Collision ◽  
Plan View ◽  
Volumetric Expansion ◽  
Ion Tracks ◽  
Swift Heavy Ion ◽  
Transmission Electron ◽  
Temperature Irradiation

AbstractPlan view and cross-section transmission electron microscopy was used to investigate the microstructure of magnesium aluminate spinel (MgAl2O4) following room temperature irradiation with either 430 MeV Kr, 614 MeV Xe, or 72 MeV I ions. The fluences ranged from 1×1016/m2 (single track regime) to 1×1020/m2. Destruction of the ordered spinel crystal structure on both the anion and cation sublattices was observed in the ion tracks at low fluences. At intermediate fluences, the overlapping ion tracks induced the formation of a new metastable crystalline phase. Amorphization with a volumetric expansion of ∼35% was observed in spinel irradiated with swift heavy ions (electronic stopping powers >7 keV/nm) at fluences above 1×1019/m2. These results demonstrate that swift heavy ion radiation can induce microstructural changes not achievable with conventional elastic collision irradiation at comparable temperatures.

Conducting ion tracks generated by charge-selected swift heavy ions

2016 ◽  
Vol 381 ◽  
pp. 76-83 ◽  
Author(s):  
Srashti Gupta ◽  
H.G. Gehrke ◽  
J. Krauser ◽  
C. Trautmann ◽  
D. Severin ◽  
...  
Keyword(s):  
Heavy Ions ◽  
Ion Tracks ◽  
Swift Heavy Ions

Structural modifications of Gd2Zr2-xTixO7 pyrochlore induced by swift heavy ions: Disordering and amorphization

2009 ◽  
Vol 24 (4) ◽  
pp. 1322-1334 ◽  
Author(s):  
M. Lang ◽  
F.X. Zhang ◽  
R.C. Ewing ◽  
Jie Lian ◽  
Christina Trautmann ◽  
...  
Keyword(s):  
Heavy Ions ◽  
Structural Changes ◽  
Pyrochlore Structure ◽  
Fluorite Structure ◽  
Structure Type ◽  
Electronic Energy ◽  
Inert Matrix ◽  
Swift Heavy Ions ◽  
Transmission Electron ◽  
Radiation Induced

The isometric, pyrochlore structure type, A2B2O7, exhibits a wide variety of properties that find application in a large number of different technologies, from electrolytes in solid oxide fuel cells to actinide-bearing compositions that can be used as nuclear waste forms or inert matrix nuclear fuels. Swift xenon ions (1.43 GeV) have been used to systematically modify different compositions in the Gd2Zr2-xTixO7 binary at the nanoscale by radiation-induced phase transitions that include the crystalline-to-amorphous and order-disorder structural transformations. Synchrotron x-ray diffraction, Raman spectroscopy, and transmission electron microscopy provide a complete and consistent description of structural changes induced by the swift heavy ions and demonstrate that the response of pyrochlore depends strongly on chemical composition. The high and dense electronic energy deposition primarily results in amorphization of Ti-rich pyrochlore; whereas the formation of the fully disordered, defect-fluorite structure is the dominant process for Zr-rich pyrochlore.

Temperature Dependence of Amorphization for Zirconolite and Perovskite Irradiated with 1 Mev Krypton Ions

1994 ◽  
Vol 353 ◽  
Author(s):  
T. J. White ◽  
R. C. Ewing ◽  
L. M. Wang ◽  
J. S. Forrester ◽  
C. Montross
Keyword(s):  
Cross Section ◽  
Heavy Ions ◽  
Arrhenius Plot ◽  
Ion Irradiation ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
Large Cross Section ◽  
Magnéli Phases ◽  
Transmission Electron ◽  
Argon Ions

AbstractA transmission electron microscope investigation was made of zirconolites and perovskites irradiated to amorphization with 1 MeV krypton ions using the HVEM-Tandem Facility at Argonne National Laboratory. Three specimens were examined - a prototype zirconolite CaZrTi2O7, a gadolinium doped zirconolite Ca0.75Gd0.50Zr0.75Ti2O7and a uranium doped zirconolite Ca0.75U0.50Zr0.75Ti2O7. The critical amorphization dose Dc was determined at several temperatures between 20K to 675K. Dc was inversely proportional with temperature. For example, pure zirconolite requiring 10x the dose for amorphization at 475K compared with gadolinium zirconolite. Using an Arrhenius plot, the activation energy Ea for annealing in these compounds was found to be 0.129 eV and 0.067 eV respectively. The greater ease of amorphization for the gadolinium sample is probably a reflection of this element’s large cross section for interaction with heavy ions. Uranium zirconolite was very susceptible to damage and amorphised under 4 keV argon ions during the preparation of microscope specimens. In each sample, zirconolite coexisted with minor perovskite, reduced rutile (Magneli phases) and zirconia. These phases were more resistant to ion irradiation than zirconolite. Even for high gadolinium loadings, perovskite (Ca0.8Gd0.2TiO3) was 3-4 times more stable to ion irradiation than the surrounding zirconolite crystals.

scholarly journals Structural Modifications of Multiwalled Carbon Nanotubes by Swift Heavy Ions Irradiation

2010 ◽  
Vol 10 ◽  
pp. 1-9 ◽  
Author(s):  
Keya Dharamvir ◽  
Kiran Jeet ◽  
Chun Sheng Du ◽  
Ning Pan ◽  
V.K. Jindal
Keyword(s):  
Carbon Nanotubes ◽  
Heavy Ions ◽  
Ion Irradiation ◽  
Raman Spectrometry ◽  
Multiwalled Carbon ◽  
Structural Modifications ◽  
Pristine Sample ◽  
Transmission Electron ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Thin film samples of multi-walled carbon nanotubes (MWCNTs) were irradiated with 120 MeV gold ions. Transmission electron microscopy (TEM) images of the pristine and irradiated samples were obtained. TEM pictures show that in the irradiated sample, the CNTs are in general shorter and some have their inner cores filled, unlike in the pristine sample. We also find from these images that average inner and outer tube diameters change as a result of ion irradiation. The films were also characterized using Raman spectrometry. Modifications of the disorder mode (D mode) and the tangential mode (G mode) under different irradiation fluences were studied in detail. As fluence increases, the MWCNTs first show damage, then healing under somewhat higher fluences and again amorphization under still higher fluence of ion irradiation.

scholarly journals Effect of Ion Irradiation on Vanadium Oxide Thin Films Deposited by Reactive RF Sputtering Technique

2019 ◽  
Vol 8 (3) ◽  
pp. 7899-7902
Keyword(s):  
Thin Films ◽  
Vanadium Oxide ◽  
Oxidation State ◽  
Heavy Ions ◽  
Ion Irradiation ◽  
Rf Sputtering ◽  
Wave Number ◽  
Oxide Thin Films ◽  
Swift Heavy Ions ◽  
Vanadium Oxide Thin Films

Vanadium has many oxides (VO2 , V2O3 , V2O4 , V6O13 and V2O5 ) due to high oxidation state. Properties of the vanadium oxide thin films can be changed by pressure, doping and strain. Ion irradiation can transform the phase, mix the two solid materials, form epitaxial crystallization and create nanostructure etc. in the materials. Purpose of our study was to observe the effect of swift heavy ions (SHIs) irradiation on vanadium oxide thin films. Thin films of vanadium oxide were deposited on the Si substrate by reactive RF sputtering technique. As-deposited thin films were irradiated by swift heavy ions (100 MeV Ag ions) at different fluences at room temperature. The effect of ions irradiation was studied by using grazing incidence X-ray diffraction (GIXRD), Fourier transform infrared spectroscopy (FTIR) and UV-vis-NIR spectrophotometer characterization techniques. GIXRD pattern revealed that swift heavy ions can induce the phase transformation (V6O13 to V2O3 ) in the films. FTIR characterization showed that δ(V=O) stretching mode at 1020 cm-1 shifted to the lower wave number side. Optical properties showed blue shift in the absorption spectra at the higher fluences. These shifting are due to the lowering of vanadium’s oxidation state in the thin films. This change in oxidation state of vanadium transforms the phase of the films. Irradiation with SHIs can transform the phase along with enhancement in the crystallinity of the vanadium oxide films.

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