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Ishikawa N, Fukuda S, Nakajima T, Ogawa H, Fujimura Y, Taguchi T. Ion Tracks and Nanohillocks Created in Natural Zirconia Irradiated with Swift Heavy Ions. MATERIALS (BASEL, SWITZERLAND) 2024; 17:547. [PMID: 38591410 PMCID: PMC10856718 DOI: 10.3390/ma17030547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 01/16/2024] [Accepted: 01/21/2024] [Indexed: 04/10/2024]
Abstract
Natural monoclinic zirconia (baddeleyite) was irradiated with 340 MeV Au ions, and the irradiation-induced nanostructures (i.e., ion tracks and nanohillocks) were observed using transmission electron microscopy. The diameter of the nanohillocks was approximately 10 nm, which was similar to the maximum molten region size calculated using the analytical thermal spike model. Ion tracks were imaged as strained regions that maintained their crystalline structure. The cross-sections of most of the ion tracks were imaged as rectangular contrasts as large as 10 nm. These results strongly indicated that the molten region was recrystallized anisotropically, reflecting the lattice structure. Furthermore, low-density track cores were formed in the center of the ion tracks. The formation of low-density track cores can be attributed to the ejection of molten matter toward the surface. A comparison of the ion tracks in the synthetic zirconia nanoparticles and those in larger natural zirconia samples showed that the interface between the strained track contrast and the matrix was less clear in the former than in the latter. These findings suggest that the recrystallization process was affected by the size of the irradiated samples.
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Affiliation(s)
- Norito Ishikawa
- Nuclear Science and Engineering Center, Japan Atomic Energy Agency (JAEA), Tokai 319-1195, Ibaraki, Japan; (H.O.); (Y.F.)
| | - Shoma Fukuda
- Tono Geoscience Center, Japan Atomic Energy Agency (JAEA), Toki 509-5102, Gifu, Japan; (S.F.); (T.N.)
| | - Toru Nakajima
- Tono Geoscience Center, Japan Atomic Energy Agency (JAEA), Toki 509-5102, Gifu, Japan; (S.F.); (T.N.)
| | - Hiroaki Ogawa
- Nuclear Science and Engineering Center, Japan Atomic Energy Agency (JAEA), Tokai 319-1195, Ibaraki, Japan; (H.O.); (Y.F.)
| | - Yuki Fujimura
- Nuclear Science and Engineering Center, Japan Atomic Energy Agency (JAEA), Tokai 319-1195, Ibaraki, Japan; (H.O.); (Y.F.)
| | - Tomitsugu Taguchi
- Foundational Quantum Technology Research Directorate, National Institutes for Quantum Science and Technology (QST), Takasaki 370-1292, Gunma, Japan;
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Pandey RK, Yadav RP, Kumar T, Kumar A, Pathak S, Awasthi S, Singh UB, Pandey AC. Fractal characterizations of MeV ion treated CaF 2 thin films. CHAOS (WOODBURY, N.Y.) 2023; 33:033110. [PMID: 37003822 DOI: 10.1063/5.0135127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 02/13/2023] [Indexed: 06/19/2023]
Abstract
We present the morphological evolution and fractal characterizations of CaF2 thin-film surfaces modified by bombardment with 100 MeV Au+8 ions at various fluences. Atomic force microscopy (AFM) combined with line profile and two-dimensional power spectral density (2D-PSD) analysis was utilized to investigate the evolution of surface morphology as a function of fluence. The AFM images were utilized to investigate the relationship between fractal dimension, roughness exponent, lateral correlation length, and ion fluence. The surface erosion owing to sputtering was depicted using Rutherford backscattering spectrometry. The structural characteristics' dependency on fluence was explored with the help of glancing angle x-ray diffraction measurements on virgin and irradiated samples. Tensile stress calculated using a peak shift in the glancing angle x-ray diffractogram showed an increase in tensile stress with fluence that caused the surface to crack after the fracture strength of the surface was crossed. 2D-PSD analysis signified the role of sputtering over surface diffusion for the observed surface modifications. Fractal dimensions first increased and then decreased with ion fluence. The lateral correlation length decreased, while the roughness exponent increased with fluence after the threshold value.
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Affiliation(s)
- Ratnesh K Pandey
- Department of Physics, School of Engineering, University of Petroleum and Energy Studies, Dehradun 248007, Uttarakhand, India
| | - Ram Pratap Yadav
- Department of Physics, Deen Dayal Upadhyay Govt. P.G. College, Saidabad, Allahabad 221508, India
| | - Tanuj Kumar
- Department of Nanosciences and Materials, Central University of Jammu, Rahya-Suchani, Bagla 181143, Jammu, India
| | - Ashish Kumar
- Department of Physics, School of Engineering, University of Petroleum and Energy Studies, Dehradun 248007, Uttarakhand, India
| | - Sachin Pathak
- Department of Physics, School of Engineering, University of Petroleum and Energy Studies, Dehradun 248007, Uttarakhand, India
| | - Shikha Awasthi
- Department of Physics, MM Mahila Mahavidyalaya, Ara 802301, India
| | - Udai B Singh
- Department of Physics, Deen Dayal Upadhyaya Gorakhpur University, 273009 Gorakhpur, India
| | - Avinash C Pandey
- Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110067, India
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Ishikawa N, Fujimura Y, Kondo K, Szabo GL, Wilhelm RA, Ogawa H, Taguchi T. Surface nanostructures on Nb-doped SrTiO 3irradiated with swift heavy ions at grazing incidence. NANOTECHNOLOGY 2022; 33:235303. [PMID: 35213855 DOI: 10.1088/1361-6528/ac58a5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 02/25/2022] [Indexed: 06/14/2023]
Abstract
A single crystal of SrTiO3doped with 0.5 wt% niobium (Nb-STO) was irradiated with 200 MeV Au32+ions at grazing incidence to characterize the irradiation-induced hillock chains. Exactly the same hillock chains are observed by using atomic force microscopy (AFM) and scanning electron microscopy (SEM) to study the relation between irradiation-induced change of surface topography and corresponding material property changes. As expected, multiple hillocks as high as 5-6 nm are imaged by AFM observation in tapping mode. It is also found that the regions in between the adjacent hillocks are not depressed, and in many cases they are slightly elevated. Line-like contrasts along the ion paths are found in both AFM phase images and SEM images, indicating the formation of continuous ion tracks in addition to multiple hillocks. Validity of preexisting models for explaining the hillock chain formation is discussed based on the present results. In order to obtain new insights related to the ion track formation, cross-sectional transmission electron microscopy (TEM) observation was performed. The ion tracks in the near-surface region are found to be relatively large, whereas buried ion tracks in the deeper region are relatively small. The results suggest that recrystallization plays an important role in the formation of small ion tracks in the deep region, whereas formation of large ion tracks in the near-surface region is likely due to the absence of recrystallization. TEM images also show shape deformation of ion tracks in the near-surface region, suggesting that material transport towards the surface is the reason for the absence of recrystallization.
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Affiliation(s)
- N Ishikawa
- Nuclear Science and Engineering Center, Japan Atomic Energy Agency (JAEA), Tokai, Ibaraki 319-1195, Japan
| | - Y Fujimura
- Nuclear Science and Engineering Center, Japan Atomic Energy Agency (JAEA), Tokai, Ibaraki 319-1195, Japan
| | - K Kondo
- Nuclear Science and Engineering Center, Japan Atomic Energy Agency (JAEA), Tokai, Ibaraki 319-1195, Japan
| | - G L Szabo
- TU Wien, Institute of Applied Physics, A-1040 Vienna, Austria
| | - R A Wilhelm
- TU Wien, Institute of Applied Physics, A-1040 Vienna, Austria
| | - H Ogawa
- Nuclear Science and Engineering Center, Japan Atomic Energy Agency (JAEA), Tokai, Ibaraki 319-1195, Japan
| | - T Taguchi
- Quantum Beam Science Research Directorate, National Institutes for Quantum Science and Technology (QST), Tokai, Ibaraki 319-1106, Japan
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Comprehensive Understanding of Hillocks and Ion Tracks in Ceramics Irradiated with Swift Heavy Ions. QUANTUM BEAM SCIENCE 2020. [DOI: 10.3390/qubs4040043] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
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.
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C 60 ions of 1 MeV are slow but elongate nanoparticles like swift heavy ions of hundreds MeV. Sci Rep 2019; 9:14980. [PMID: 31628343 PMCID: PMC6800440 DOI: 10.1038/s41598-019-49645-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Accepted: 08/19/2019] [Indexed: 12/01/2022] Open
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.
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