文献类型：期刊文献

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

机构：[1] Institute of Plasma Physics, HFIPS, Chinese Academy of Sciences, Hefei, 230031, China; [2] University of Science and Technology of China, Hefei, 230026, China; [3] Department of Physics, Xinxiang University, Xinxiang, 453000, China

第一机构：Institute of Plasma Physics, HFIPS, Chinese Academy of Sciences, Hefei, 230031, China

通讯机构：[1]Institute of Plasma Physics, HFIPS, Chinese Academy of Sciences, Hefei, 230031, China

年份：2023

卷号：574

外文期刊名：Journal of Nuclear Materials

收录：EI(收录号：20224813187690);Scopus(收录号：2-s2.0-85142738703)

语种：英文

外文关键词：Alumina - Aluminum oxide - Atoms - Calculations - Diffusion barriers - Dissolution - Hydrogen

摘要：First-principles theory is applied to identify the structure of γ-Al2O3 first. Then, hydrogen dissolution and diffusion behavior was further studied to reveal the reason that permeation reduction factor (PRF) of γ-Al2O3 is lower than that of α-Al2O3. Our calculations show that the formation energy for Al vacancy at the octahedral interstitial site (VAl?OIS?3) is lower than that at the tetrahedral interstitial site (VAl?TIS?3), and are far lower than those of other defects in both defective spinel and non-spinel γ-Al2O3. Thus, the stability of VAl?OIS?3 is higher than that of VAl?TIS?3 in both Al-rich and O-rich environments. However, when hydrogen atoms are introduced into γ-Al2O3, the stability of [VAl-TIS-H]?2 is higher than that of [VAl-OIS-H]?2 in the defective spinel γ-Al2O3 structure, while the opposite is true for the non-spinel γ-Al2O3 structure. The vibrational frequencies for OH? in [VAl-TIS-H]?2 and [VAl-OIS-H]?2 for defective γ-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 ～3500 and ～3300 cm?1. The defective spinel model is more suitable for describing the γ-Al2O3 structure. In defective spinel γ-Al2O3, there are many native Al vacancies, which are arranged in a straight line along the [21ˉ1ˉ0] 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 γ-Al2O3 is much higher than that in α-Al2O3 leading to a lower permeation reduction factor (PRF). Our results can provide not only a sound theoretical explanation for the low PRF of γ-Al2O3 but also a direction to improve the efficiency in preventing H permeation through FeAl/Al2O3 tritium permeation barriers (TPBs). ? 2022