Ab initio study of helium in Li4SiO4 crystals: Electronic properties, migration, and vacancy capture mechanism
| Autor: | Lei Wan, Chengjian Xiao, Jiangnan Wang, Tao Gao, Ruijie Zhang, Huagang Xiao, Xiaojun Chen |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Materials science
Nucleation Ab initio chemistry.chemical_element 02 engineering and technology 01 natural sciences Molecular physics Crystal Condensed Matter::Materials Science Vacancy defect 0103 physical sciences Atom Physics::Atomic and Molecular Clusters Materials Chemistry Physics::Atomic Physics Helium Condensed Matter::Quantum Gases 010302 applied physics Process Chemistry and Technology Charge density 021001 nanoscience & nanotechnology Surfaces Coatings and Films Electronic Optical and Magnetic Materials chemistry Ceramics and Composites Density functional theory 0210 nano-technology |
| Zdroj: | Ceramics International. 47:20239-20247 |
| ISSN: | 0272-8842 |
| DOI: | 10.1016/j.ceramint.2021.04.031 |
| Popis: | Li4SiO4 crystal is a candidate material for tritium breeder material. Vacancy defects and He atoms will be produced in the crystal after neutron irradiation in fusion reactor. In previous research, we learned vacancy defects mainly include VO0, VO2+, and VLi0, meanwhile, He atoms are easy to migrate and aggregate in the crystal. In order to understand the relationship between vacancy defects and He atoms, we use density functional theory (DFT) to study the interaction mechanism between vacancy and He atom. The results show that the local stable sites of He atoms are related to the surrounding charge distribution. VO2+ and VLi0 can capture interstitial He atoms, and it is difficult to escape the vacancies, thereby increasing the nucleation center of He atoms. VO0 promotes the diffusion of He atoms in the interstitial space, which will cause small helium bubbles to merge more easily. |
| Databáze: | OpenAIRE |
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