Absence of single critical dose for the amorphization of quartz under ion irradiation

作者：Zhang, S.; Pakarinen, O. H.; Backholm, M.; Djurabekova, F.; Nordlund, K.; Keinonen, J.; Wang, T. S.^*

来源：Journal of Physics: Condensed Matter , 2018, 30(1): 015403.

DOI：10.1088/1361-648X/aa9868

• amorphization of quartz
• ion irradiation
• Rutherford backscattering spectrometry in channelling conditions
• molecular dynamics

In this work, we first simulated the amorphization of crystalline quartz under 50 keV Na-23 ion irradiation with classical molecular dynamics (MD). We then used binary collision approximation algorithms to simulate the Rutherford backscattering spectrometry in channeling conditions (RBS-C) from these irradiated MD cells, and compared the RBS-C spectra with experiments. The simulated RBS-C results show an agreement with experiments in the evolution of amorphization as a function of dose, showing what appears to be (by this measure) full amorphization at about 2.2 eV.atom(-1). We also applied other analysis methods, such as angular structure factor, Wigner-Seitz, coordination analysis and topological analysis, to analyze the structural evolution of the irradiated MD cells. The results show that the atomic-level structure of the sample keeps evolving after the RBS signal has saturated, until the dose of about 5 eV.atom(-1). The continued evolution of the SiO2 structure makes the definition of what is, on the atomic level, an amorphized quartz ambiguous.

• 出版日期2018-1-10
• 单位兰州大学