Influence of irradiation-induced point defects on the dissolution and diffusion properties of hydrogen in alpha-Al2O3: a first-principles study

doi:10.1088/1741-4326/abcf8c

	Influence of irradiation-induced point defects on the dissolution and diffusion properties of hydrogen in alpha-Al2O3: a first-principles study
	Pan, Xin-Dong 1,4; Xu, Yu-Ping 4; Lu, Tao 2; Zhou, Hai-Shan 4; Li, Xiao-Chun 4; Gao, Fei 3; Luo, Guang-Nan 1,4
刊名	NUCLEAR FUSION
	2021-03-01
卷号	61
关键词	defects irradiation first-principles alpha-Al2O3 tritium permeation barrier
ISSN号	0029-5515
DOI	10.1088/1741-4326/abcf8c
通讯作者	Li, Xiao-Chun(xcli@ipp.ac.cn) ; Gao, Fei(gaofeium@umich.edu)
英文摘要	Alpha-alumina (alpha-Al2O3) is considered to be an ideal candidate material for the tritium permeation barrier (TPB) with excellent tritium resistance properties. However, in a fusion reactor, the irradiation-induced defects could sum up on fabrication-induced defects so to reduce drastically the barrier performance. The underlying mechanism is still not settled. In this paper, the first-principles density functional theory (DFT) approach is used to explore the influence of irradiation-induced point defects on the dissolution and diffusion properties of hydrogen (H) in alpha-Al2O3. [H+-VAl-3H] and [H+ -V-O(0)] defects have much lower formation energies at E-G/2 in both Al-rich and O-rich growth environments that H atoms are easily captured by vacancy-type irradiation-induced point defects. As a result, higher H retention can be expected, which is consistent with the experimental results. Moreover, by calculating several different diffusion pathways of H-defect complexes and the corresponding diffusion coefficient, it can be inferred that H atoms and vacancy-type point defects can hardly diffuse as a bound entity. Therefore, isolated vacancy-type irradiation-induced point defects can trap multiple H atoms to form H-defect complexes and impede the diffusion process of H, which can enhance the efficiency of protection against H permeation through alpha-Al2O3 TPB. However, the minimum diffusion barrier for OiH- migration to the first nearest neighbor O interstitial site is 0.44 eV, which is so low that OiH- can migrate quickly at room temperature. This fast diffusion pathway for H could be the underlying mechanism for the low efficiency in preventing H permeation through irradiated alpha-Al2O3. Our results provide a sound theoretical explanation for recent experimental results of H permeation in alpha-Al2O3 under irradiation environment.
资助项目	National Natural Science Foundation of China[11975260] ; National Natural Science Foundation of China[11905246] ; National Natural Science Foundation of China[11705232] ; National Natural Science Foundation of China[11705233] ; National Natural Science Foundation of China[11875287]
WOS关键词	DEUTERIUM PERMEATION BEHAVIOR ; TRITIUM PERMEATION ; NEUTRON-IRRADIATION ; ALUMINA CERAMICS ; GRAIN-BOUNDARY ; AL2O3 ; BARRIER ; CR ; 1000-DEGREES-C ; SAPPHIRE
WOS研究方向	Physics
语种	英语
出版者	IOP PUBLISHING LTD
WOS记录号	WOS:000612011400001
资助机构	National Natural Science Foundation of China
内容类型	期刊论文
源URL	[http://ir.hfcas.ac.cn:8080/handle/334002/119692]
专题	中国科学院合肥物质科学研究院
通讯作者	Li, Xiao-Chun; Gao, Fei
作者单位	1.Univ Sci & Technol China, Hefei 230031, Peoples R China 2.Beijing Aviat Meteorol Inst, Beijing 100085, Peoples R China 3.Univ Michigan, Dept Nucl Engn & Radiol Sci, Ann Arbor, MI 48109 USA 4.Chinese Acad Sci, Inst Plasma Phys, HFIPS, Hefei 230031, Peoples R China
推荐引用方式 GB/T 7714	Pan, Xin-Dong,Xu, Yu-Ping,Lu, Tao,et al. Influence of irradiation-induced point defects on the dissolution and diffusion properties of hydrogen in alpha-Al2O3: a first-principles study[J]. NUCLEAR FUSION,2021,61.
APA	Pan, Xin-Dong.,Xu, Yu-Ping.,Lu, Tao.,Zhou, Hai-Shan.,Li, Xiao-Chun.,...&Luo, Guang-Nan.(2021).Influence of irradiation-induced point defects on the dissolution and diffusion properties of hydrogen in alpha-Al2O3: a first-principles study.NUCLEAR FUSION,61.
MLA	Pan, Xin-Dong,et al."Influence of irradiation-induced point defects on the dissolution and diffusion properties of hydrogen in alpha-Al2O3: a first-principles study".NUCLEAR FUSION 61(2021).