金红石TiO2辐照损伤模拟研究

A Simulation Study on Irradiation Damage of Rutile TiO2

  • 摘要: 利用分子动力学方法对金红石TiO2中O及Ti沿着不同方向的离位阈能进行模拟计算,结果表明:各方向O的离位阈能普遍低于Ti的离位阈能,O的离位阈能基本在27.50~77.50 eV之间,而Ti的离位阈能在90.00~120.00 eV之间。同时对能量为1.0、5.0和10.0 keV的O PKA及Ti PKA造成的级联辐照损伤进行探究,结果表明:能量小于10.0 keV的O PKA及Ti PKA产生的主要是点缺陷,且点缺陷的数量在0.10~0.20 ps内达到峰值,在经过数ps的演化后,超过90.0%以上的缺陷复合,只有不足10.0%的缺陷保留下来,即金红石TiO2中的缺陷在缺陷产生初期有较高的自我恢复能力。

     

    Abstract: In this study, threshold displacement energy of O and Ti in rutile TiO2 along different directions is simulated by using the method of molecular dynamics. Simulation results show that threshold displacement energy of O atom in all directions is generally lower than that of Ti atom. The threshold displacement energy of O is basically between 27.50 and 77.50 eV, while that of Ti is between 90.00 and 120.00 eV. Meanwhile, this study also explores the cascade radiation damage caused by O PKA and Ti PKA with energy of 1.0, 5.0 and 10.0 keV. Cascade radiation damage results show that O PKA and Ti PKA with energy less than 10.0 keV mainly produced point defects. The number of point defects reached the peak within 0.10~0.20 ps. After several ps evolution, more than 90.0% of the defects are annealing, and only less than 10.0% defects remained. In other words, the defects in rutile TiO2 have higher self-recovery ability at the initial stage of defect generation.

     

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