Molecular Dynamics Simulation of High-Energy Beam Irradiation of SiO2 Single Crystal with Three Different Morphologies: No Free Surface, with a Free Surface, and Thin Films

S Otsuka and S Kimata and Y Sasajima and N Ishikawa, ECS JOURNAL OF SOLID STATE SCIENCE AND TECHNOLOGY, 13, 114005 (2024).

DOI: 10.1149/2162-8777/ad905a

High-energy beam irradiation of SiO2 crystal with the alpha-quartz structure was simulated by the molecular dynamics method. Three types of specimen structures were examined: a single crystal without a free surface, a single crystal with a free surface, and a thin film. After structural relaxation at room temperature, a cylindrical region with diameter of 3.0 nm was set at the center of the specimen and high- thermal energy of S-eff = 0.1-4.0 keV nm(-1) was added to that region, where S-eff is the effective stopping power. Atomic motions were calculated by the molecular dynamics method using the large-scale atomic/molecular massively parallel simulator. Vashishta potential was used for the atomic interaction. The single crystal structure of alpha- quartz without the free surface was stable up to 1.0 keV nm(-1) and it gradually became amorphous with increasing thermal energy. In contrast, the single crystal structure with the free surface was stable up to 0.5 keV nm(-1) and was amorphous at higher thermal energy. In particular, the atomic structures for the thermal impact S-eff >= 2.0 keV nm(-1) had a facet-like structure at the impacted surface, which corresponds to actual experimental results. Nano-hole formation was observed in the irradiation process of the fi lm structure. (c) 2024 The Electrochemical Society ("ECS"). Published on behalf of ECS by IOP Publishing Limited. All rights, including for text and data mining, AI training, and similar technologies, are reserved.

Return to Publications page