Primary radiation damage in silicon from the viewpoint of a machine learning interatomic potential
Autor: | Abdolhamid Minuchehr, J. Byggmästar, Gh. Alahyarizadeh, Flyura Djurabekova, Kai Nordlund, Reza Ghaderi, A. Hamedani |
---|---|
Přispěvatelé: | Helsinki Institute of Physics, Department of Physics |
Rok vydání: | 2021 |
Předmět: |
Recrystallization (geology)
Materials science Physics and Astronomy (miscellaneous) Silicon chemistry.chemical_element Interatomic potential 02 engineering and technology THRESHOLD DISPLACEMENT ENERGIES SEMICONDUCTORS CASCADES 114 Physical sciences 01 natural sciences Molecular physics EMBEDDED-ATOM METHOD COMPUTER-SIMULATION Molecular dynamics Phase (matter) Vacancy defect 0103 physical sciences Cluster (physics) General Materials Science 010306 general physics ORDER Order (ring theory) DEFECTS 021001 nanoscience & nanotechnology MODEL chemistry MOLECULAR-DYNAMICS METALS 0210 nano-technology |
Zdroj: | Physical Review Materials. 5 |
ISSN: | 2475-9953 |
Popis: | Characterization of the primary damage is the starting point in describing and predicting the irradiation-induced damage in materials. So far, primary damage has been described by traditional interatomic potentials in molecular dynamics simulations. Here, we employ a Gaussian approximation machine-learning potential (GAP) to study the primary damage in silicon with close to ab initio precision level. We report detailed analysis of cascade simulations derived from our modified Si GAP, which has already shown its reliability for simulating radiation damage in silicon. Major differences in the picture of primary damage predicted by machine-learning potential compared to classical potentials are atomic mixing, defect state at the heat spike phase, defect clustering, and recrystallization rate. Atomic mixing is higher in the GAP description by a factor of two. GAP shows considerably higher number of coordination defects at the heat spike phase and the number of displaced atoms is noticeably greater in GAP. Surviving defects are dominantly isolated defects and small clusters, rather than large clusters, in GAP's prediction. The pattern by which the cascades are evolving is also different in GAP, having more expanded form compared to the locally compact form with classical potentials. Moreover, recovery of the generated defects at the heat spike phase take places with higher efficiency in GAP. We also provide the attributes of the new defect cluster that we had introduced in our previous study. A cluster of four defects, in which a central vacancy is surrounded by three split interstitials, where the surrounding atoms are all 4-folded bonded. The cluster shows higher occurrence in simulations with the GAP potential. The formation energy of the defect is 5.57 eV and it remains stable up to 700 K, at least for 30 ps. The Arrhenius equation predicts the lifetime of the cluster to be $0.0725\phantom{\rule{0.16em}{0ex}}\ensuremath{\mu}\mathrm{s}$ at room temperature. |
Databáze: | OpenAIRE |
Externí odkaz: |