Amekura H, Chettah A, Narumi K, Chiba A, Hirano Y, Yamada K, Yamamoto S, Leino A A, Djurabekova F, Nordlund K, Ishikawa N, Okubo N, Saitoh Y
National Institute for Materials Science (NIMS), Tsukuba, Ibaraki, 305-0003, Japan.
Department of Physics, LGMM laboratory, University of 20 Août 1955-Skikda, BP 26, route d'El Hadaiek-Skikda, Skikda, 21000, Algeria.
Nat Commun. 2024 Feb 27;15(1):1786. doi: 10.1038/s41467-024-45934-4.
Injecting high-energy heavy ions in the electronic stopping regime into solids can create cylindrical damage zones called latent ion tracks. Although these tracks form in many materials, none have ever been observed in diamond, even when irradiated with high-energy GeV uranium ions. Here we report the first observation of ion track formation in diamond irradiated with 2-9 MeV C fullerene ions. Depending on the ion energy, the mean track length (diameter) changed from 17 (3.2) nm to 52 (7.1) nm. High resolution scanning transmission electron microscopy (HR-STEM) indicated the amorphization in the tracks, in which π-bonding signal from graphite was detected by the electron energy loss spectroscopy (EELS). Since the melting transition is not induced in diamond at atmospheric pressure, conventional inelastic thermal spike calculations cannot be applied. Two-temperature molecular dynamics simulations succeeded in the reproduction of both the track formation under MeV C irradiations and the no-track formation under GeV monoatomic ion irradiations.
在电子阻止 regime 中将高能重离子注入固体中会产生称为潜伏离子径迹的圆柱形损伤区。尽管这些径迹在许多材料中都会形成，但即使在用高能 GeV 铀离子辐照时，在金刚石中也从未观察到过。在此我们报告首次观察到用 2 - 9 MeV 的 C 富勒烯离子辐照金刚石时离子径迹的形成。根据离子能量，平均径迹长度（直径）从 17（3.2）nm 变化到 52（7.1）nm。高分辨率扫描透射电子显微镜（HR - STEM）表明径迹中发生了非晶化，通过电子能量损失谱（EELS）在其中检测到了来自石墨的 π 键信号。由于在大气压下金刚石不会发生熔化转变，传统的非弹性热尖峰计算无法应用。双温分子动力学模拟成功再现了 MeV C 辐照下的径迹形成以及 GeV 单原子离子辐照下的无径迹形成。
