Density functional theory calculations of point defects and hydrogen isotopes in Li4SiO4
Xiaogang Xiang,
Wenjun Zhu,
Tiecheng Lu,
Tao Gao,
Yanli Shi,
Mao Yang,
Yichao Gong,
Xiaohe Yu,
Lan Feng,
Yongkai Wei,
Zhipeng Lu
Affiliations
Xiaogang Xiang
Key Laboratory of High Energy Density Physics and Technology of Ministry of Education, College of Physical Science and Technology, Sichuan University, Chengdu 610064, China
Wenjun Zhu
National Key Laboratory of Shock Wave and Detonation Physics, Institute of Fluid Physics, Chinese Academy of Engineering Physics, Mianyang 621900, China
Tiecheng Lu
Key Laboratory of High Energy Density Physics and Technology of Ministry of Education, College of Physical Science and Technology, Sichuan University, Chengdu 610064, China
Tao Gao
Institute of Atomic and Molecular Physics, College of Physical Science and Technology, Sichuan University, Chengdu 610065, China
Yanli Shi
Key Laboratory of High Energy Density Physics and Technology of Ministry of Education, College of Physical Science and Technology, Sichuan University, Chengdu 610064, China
Mao Yang
Key Laboratory of High Energy Density Physics and Technology of Ministry of Education, College of Physical Science and Technology, Sichuan University, Chengdu 610064, China
Yichao Gong
Key Laboratory of High Energy Density Physics and Technology of Ministry of Education, College of Physical Science and Technology, Sichuan University, Chengdu 610064, China
Xiaohe Yu
Key Laboratory of High Energy Density Physics and Technology of Ministry of Education, College of Physical Science and Technology, Sichuan University, Chengdu 610064, China
Lan Feng
Institute of Atomic and Molecular Physics, College of Physical Science and Technology, Sichuan University, Chengdu 610065, China
Yongkai Wei
Key Laboratory of High Energy Density Physics and Technology of Ministry of Education, College of Physical Science and Technology, Sichuan University, Chengdu 610064, China
Zhipeng Lu
Department of Mathematics and Physics, Officer College of the Chinese People’s Armed Police Force, Chengdu 610213, China
The Li4SiO4 is a promising breeder material for future fusion reactors. Radiation induced vacancies and hydrogen isotope related impurities are the major types of point defects in this breeder material. In present study, various kinds of vacancies and hydrogen isotopes related point defects in Li4SiO4 are investigated through density functional theory (DFT) calculations. The band gap of Li4SiO4 is determined by UV-Vis diffuse reflectance spectroscopy experiments. Formation energies of all possible charge states of Li, Si and O vacancies are calculated using DFT methods. Formation energies of possible charge states of hydrogen isotopes substitution for Li and O are also calculated. We found that Li-vacancies will dominate among all vacancies in neutral charge state under radiation conditions and the O, Li, and Si vacancies (VO,VLi,VSi) are stable in charge states +2, -1, -4 for most of the range of Fermi level, respectively. The interstitial hydrogen isotopes (Hi) and substitutional HLi are stable in the charge states +1, 0 for most of the range of Fermi level, respectively. Moreover, substitutional HO are stable in +1 charge states. We also investigated the process of tritium recovery by discussing the interaction between interstitial H and Li-vacancy, O-vacancy, and found that H O + and H Li 0 are the most common H related defects during radiation process.
