Amekura H, Narumi K, Chiba A, Hirano Y, Yamada K, Tsuya D, Yamamoto S, Okubo N, Ishikawa N, Saitoh Y
National Institute for Materials Science (NIMS), Tsukuba, Ibaraki, Japan.
National Institutes for Quantum and Radiological Science and Technology (QST), Takasaki, Japan.
Sci Rep. 2019 Oct 18;9(1):14980. doi: 10.1038/s41598-019-49645-5.
This study reports that high fluence fullerene ion (C) irradiation of 1-6 MeV, which was made possible by a new-type of high-flux ion source, elongates metal nanoparticles (NPs) in amorphous SiO as efficiently as swift heavy ions (SHIs) of 200 MeV Xe, i.e., two orders of the magnitude higher energy ions. Comparing the irradiation effects induced by both the beams, the stopping processes of C ions in SiO are discussed in this paper. Despite of having almost the same elongation efficiency, the C 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 SiO under 4 MeV C 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 C 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.
本研究报告称，通过新型高通量离子源实现的1 - 6 MeV高通量富勒烯离子（C）辐照，在非晶态SiO₂中使金属纳米颗粒（NPs）伸长的效率与200 MeV Xe的快重离子（SHIs）相当，即能量高出两个数量级的离子。比较两种束流引起的辐照效应，本文讨论了C离子在SiO₂中的阻止过程。尽管伸长效率几乎相同，但由于团簇增强和/或协同效应，C辐照引起的溅射效率提高了约10倍。在4 MeV C辐照下，在晶体SiO₂中观察到直径约10.4 nm、长度60 - 80 nm的离子径迹。虽然径迹直径与相同电子阻止的SHIs产生的径迹直径相当，但比刚性C分子模型预测的径迹长度短得多，这表明由于核碰撞发生了碎片化。金属NPs的伸长仅在观察到径迹的深度以下诱导发生，而不会超出该深度。
