电子束对ZnO和TiO_(2)辐照损伤的模拟计算  

Simulation study of electron beam irradiation damage to ZnO and TiO_(2)

作　　者：高旭东 杨得草 魏雯静 李公平[1] Gao Xu-Dong;Yang De-Cao;Wei Wen-Jing;Li Gong-Ping(School of Nuclear Science and Technology,Lanzhou University,Lanzhou 730000,China)

机构地区：[1]兰州大学核科学与技术学院,兰州730000

出　　处：《物理学报》2021年第23期215-224,共10页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:11975006,11575074)资助的课题.

摘　　要：电子辐照在材料中产生的缺陷主要是相互独立的空位-间隙原子对,由于不同靶原子的离位阈能不同,通过改变电子束的能量可以调控在材料中产生的缺陷类型,同时,电子的注量又可以决定电子辐照产生的缺陷的浓度.ZnO和TiO_(2)的磁光电特性受Zn空位、Ti空位、O空位、Zn间隙原子、Ti间隙原子等缺陷的影响,因此可以通过电子辐照的方法在ZnO和TiO_(2)中产生不同浓度的各类缺陷进而研究缺陷对材料磁光电特性的影响.本文利用MCNP5程序结合蒙特卡罗辅助经典(MCCM)算法模拟计算了不同能量的点源电子束及面源电子束在纤锌矿ZnO和金红石TiO_(2)中产生的辐照损伤(dpa)的大小及分布.计算结果表明,点源电子束在样品内部产生的dpa随着入射深度的增加先增大后减小,而在横向方向很快衰减;面源电子束产生的辐照损伤在样品内部随着入射深度的增加同样呈现先增加后减小的趋势,同时dpa的最大值与电子束能量呈二次函数的关系;电子束能量沉积的计算结果表明,能量沉积区域的大小与电子束能量密切相关,同时随着电子束能量的增加,能量沉积最大值出现的位置逐渐向样品内部移动,整个能量沉积区域具有前倾的趋势.Wurtzite ZnO and rutile TiO_(2) have important application value in solar cells,photocatalysts,self-cleaning coatings,etc.In addition,ZnO and TiO_(2) are crucial basic materials for the development of semiconductor spintronics devices due to room temperature ferromagnetism in the state of defects or doped specific elements.Many studies indicate that the magnetic,optical,and electrical properties of ZnO and TiO_(2) are affected by intrinsic defects(such as vacancies,interstitial atoms,etc.).Electron irradiation has the incomparable advantages over other particle beam irradiation,the defects produced by electron beam irradiation are mainly independent vacancy-interstitial atom pairs(Frenkel pairs),and there are no new doping elements introduced into the material during the irradiation by electron beam with energy of several MeV,that is,electron irradiation is a relatively“pure”particle irradiation method.On the one hand,since the displacement threshold energy values of different atoms are different from each other,the type of defect during electron irradiation can be controlled by the energy of the electron beam.On the other hand,the electron fluence can determine the concentration of defects.Therefore,various defects of different concentrations can be generated by electron irradiation,thereby studying the influences of related defects on the magnetic,optical,and electrical properties of ZnO and TiO_(2).However,simulation calculations related to electron beam irradiation damage are relatively scarce.Therefore,in this work,the electron beam irradiation damage is taken as a research topic and the related theoretical simulation calculations are carried out,which lays a theoretical foundation for subsequent experimental researches.The size and the distribution of radiation damage(dpa)caused by point source electrons and that by plane source electrons with different energy values in ZnO and TiO_(2) are simulated and calculated through the MCNP5 program combined with the MCCM algorithm.The calculation results show th

关 键 词：电子辐照 蒙特卡罗辅助经典算法 ZNO TiO_(2) 

分 类 号：TQ132.41[化学工程—无机化工] TQ134.11