Recrystallization as the governing mechanism of ion track formation
Recrystallization as the governing mechanism of ion track formation
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DOI：
10.1038/s41598-019-40239-9
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发表时间：
2019-03-07
影响因子：
4.6
通讯作者：
Volkov, A. E.
中科院分区：
文献类型：
--
作者：
Rymzhanov, R. A.;Medvedev, N.;Volkov, A. E.
研究了介电晶体MgO、Al2O3和Y3Al5O12 （YAG）对167 MeV Xe离子在电子停止状态下减速辐照的响应。综合模拟表明，尽管电子系统和晶格的离子能量损失和初始激发动力学相似，但这些材料中离子轨道的最终结构存在显着差异，这得到了实验的支持。在MgO中没有出现离子轨迹，而在Al2O3中观察到直径约为2 nm的不连续畸变晶迹，在YAG中观察到连续的非晶轨迹。用高分辨率透射电镜证实了Al2O3和YAG中的这些径迹结构。模拟使我们能够确定再结晶是这些氧化物中检测到的轨迹形成的主要机制。分析了熔态粘度、晶格结构以及结晶表面金属亚晶格和氧亚晶格动力学差异对轨道损伤恢复的影响。
Response of dielectric crystals: MgO, Al2O3 and Y3Al5O12 ( YAG) to irradiation with 167 MeV Xe ions decelerating in the electronic stopping regime is studied. Comprehensive simulations demonstrated that despite similar ion energy losses and the initial excitation kinetics of the electronic systems and lattices, significant differences occur among final structures of ion tracks in these materials, supported by experiments. No ion tracks appeared in MgO, whereas discontinuous distorted crystalline tracks of similar to 2 nm in diameter were observed in Al2O3 and continuous amorphous tracks were detected in YAG. These track structures in Al2O3 and YAG were confirmed by high resolution TEM data. The simulations enabled us to identify recrystallization as the dominant mechanism governing formation of detected tracks in these oxides. We analyzed effects of the viscosity in molten state, lattice structure and difference in the kinetics of metallic and oxygen sublattices at the crystallization surface on damage recovery in tracks.