文献类型：期刊文献

英文题名：First-principles insight of hydrogen dissolution and diffusion properties in ?-Al2O3

作者：Pan, Xin-Dong[1];Li, Xiao-Chun[1];Wang, Jinlong[1,3];Xu, Bai-Chuan[1,2];Lyu, Yi-Ming[1];Xu, Yu-Ping[1];Zhao, Xueli[1,2];Zhou, Hai -Shan[1];Luo, Guang-Nan[1,2]

第一作者：Pan, Xin-Dong

通讯作者：Li, XC[1];Zhou, HS[1]

机构：[1]Chinese Acad Sci, Inst Plasma Phys, HFIPS, Hefei 230031, Peoples R China;[2]Univ Sci & Technol China, Hefei 230026, Peoples R China;[3]Xinxiang Univ, Dept Phys, Xinxiang 453000, Peoples R China

第一机构：Chinese Acad Sci, Inst Plasma Phys, HFIPS, Hefei 230031, Peoples R China

通讯机构：[1]corresponding author), Chinese Acad Sci, Inst Plasma Phys, HFIPS, Hefei 230031, Peoples R China.

年份：2023

卷号：574

外文期刊名：JOURNAL OF NUCLEAR MATERIALS

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000904329400001)】；

基金：This work is supported by Project funded by China Postdoctoral Science Foundation (NO. 2021M703252 ), the HFIPS Director's Fund (Grant No. YZJJ2022QN21) the National Natural Science Foundation of China (Nos. 11905246 , 11975260 ). Collaborative Innovation Program of Hefei Science Center, CAS (NO. 2022HSC-CIP010) and 2021 Anhui Province postdoctoral researchers research activities funding project, People's Republic of China (NO. 2021A481). The numerical calculations in this paper have been done on Hefei advanced computing center.

语种：英文

外文关键词：γ -Al (2) O (3); First-principles theory; Vibration; Hydrogen; Permeation

摘要：First-principles theory is applied to identify the structure of gamma-Al2O3 first. Then, hydrogen dissolution and diffusion behavior was further studied to reveal the reason that permeation reduction factor (PRF) of gamma-Al2O3 is lower than that of alpha-Al2O3. Our calculations show that the formation energy for Al vacancy at the octahedral interstitial site ( VAl-3 -OIS) is lower than that at the tetrahedral interstitial site ( V-3 Al -TIS), and are far lower than those of other defects in both defective spinel and non-spinel gamma-Al2O3. Thus, the stability of V-3 Al -OIS is higher than that of VAl-3 -TIS in both Al-rich and O-rich environments. However, when hydrogen atoms are introduced into gamma-Al2O3, the stability of [VAl-TIS-H] -2 is higher than that of [VAl-OIS-H] -2 in the defective spinel gamma-Al2O3 structure, while the opposite is true for the non-spinel gamma- Al2O3 structure. The vibrational frequencies for OH- in [VAl-TIS-H] -2 and [VAl-OIS-H] -2 for defective gamma- Al2O3 are calculated to be 3608 cm -1 and 3374 cm -1, respectively, which is in excellent agreement with the infrared (IR) absorption peaks observed at similar to 3500 and similar to 3300 cm -1. The defective spinel model is more suitable for describing the gamma-Al2O3 structure. In defective spinel gamma-Al2O3, there are many native Al vacancies, which are arranged in a straight line along the [ 2 1 over line 1 over line 0 ] direction. The migration barrier for H diffusion along these native Al vacancies is so low that these Al vacancies can provide a rapid diffusion channel for H. Thus, the permeability of H in gamma-Al2O3 is much higher than that in alpha-Al2O3 leading to a lower permeation reduction factor (PRF). Our results can provide not only a sound theoretical explanation for the low PRF of gamma-Al2O3 but also a direction to improve the efficiency in preventing H permeation through FeAl/Al2O3 tritium permeation barriers (TPBs).(c) 2022 Elsevier B.V. All rights reserved.