铀对α-Al_(2)O_(3)中氢与本征点缺陷相互作用的影响  

Uranium effect on hydrogen interactions with intrinsic point defects inα-Al_(2)O_(3)

作　　者：杨飞龙[1] 向鑫[1] 胡立 张桂凯[1] 陈长安[1] YANG Fei-Long;XIANG Xin;HU Li;ZHANG Gui-Kai;CHEN Chang-An(Institute of Materials,China Academy of Engineering Physics,Jiangyou 621908,China)

机构地区：[1]中国工程物理研究院材料研究所,江油621908

出　　处：《原子与分子物理学报》2025年第5期123-129,共7页Journal of Atomic and Molecular Physics

基　　金：国家自然科学基金(11975213,11935011);中国工程物理研究院基金(WDZC202105,TCGH070405)。

摘　　要：在长期高温服役过程中,铀床的氚渗透泄露问题是聚变堆涉氚系统中需要关注的焦点之一,而一种行之有效的解决思路是在内壁制备阻氚涂层.然而,服役过程中通过热扩散渗入涂层内部的铀可能在阻氚涂层氢行为中起作用,进而影响其服役可靠性.基于此,采用第一性原理计算方法,研究了铀对α-Al_(2)O_(3)中氢与本征点缺陷相互作用的影响.结果发现,铀对α-Al_(2)O_(3)中空位型本征点缺陷及氢相关缺陷的存在形式、电荷态及相对稳定性有重要影响.从形成能观点来看,铀对α-Al_(2)O_(3)中空位型本征点缺陷及氢相关缺陷的形成有利,且α-Al_(2)O_(3)中空位型点缺陷对氢的捕陷能力因铀的引入显著增加.研究结果对α-Al_(2)O_(3)基内壁阻氚涂层在氚工艺系统铀床中应用的可靠性评估具有重要的指导意义.The tritium permeation and leak is one of the most concerns for uranium beds under the long term service condition of high temperatures in Tritium-related systems of fusion reactor,and fabrication of tritium permeation barriers(TPBs)on the inner walls of uranium beds is an effective proposal.However,uranium penetrated into TPBs via thermal diffusion may play a role in hydrogen behaviors in TPBs,and consequently affect the service reliability of TPBs.The uranium effect on the hydrogen interactions with intrinsic point defects inα-Al_(2)O_(3)was thus investigated based on first-principles calculations.It is found that uranium has significant influence on the existing form,charge state and relative stability of vacancy type intrinsic point defects and hydrogen related defects inα-Al_(2)O_(3).From the viewpoint of formation energy,uranium is beneficial for the formation of vacancy type intrinsic point defects and hydrogen related defects inα-Al_(2)O_(3),and the hydrogen trapping ability by vacancy type point defects inα-Al_(2)O_(3)will be remarkably enhanced by the addition of uranium.The results obtained are instructive for the reliability assessment for the applications ofα-Al_(2)O_(3)-based inner wall TPBs in uranium beds in tritium handling systems.

关 键 词：铀 本征点缺陷 氢相关缺陷 相互作用 α-Al_(2)O_(3) 

分 类 号：O46[理学—电子物理学]