• Acta Physica Sinica
  • Vol. 68, Issue 12, 126701-1 (2019)
Qin Ran, Huan Wang, Rui Zhong, Jian-Chun Wu, Yu Zou*, and Jun Wang*
DOI: 10.7498/aps.68.20190310 Cite this Article
Qin Ran, Huan Wang, Rui Zhong, Jian-Chun Wu, Yu Zou, Jun Wang. Diffusion behavior of di-interstitials with different configurations in tungsten[J]. Acta Physica Sinica, 2019, 68(12): 126701-1 Copy Citation Text show less

Abstract

Tungsten, due to its desirable properties (high melting point, low sputtering coefficient, good irradiation resistance etc.), is considered as a promising candidate for the plasma facing materials in future nuclear fusion reactors. Therefore, it will work in extremely harsh environments because it is subjected to the bombadement of high-flux plasma particles and the irradiation of high energy neutrons, resulting in vacancies and interstitials. The migration behavior of self-interstitial atoms is one of the most important factors determining the microstructure evolution in irradiated metals because it will greatly affect the mechanical properties of materials. The study of the diffusion behavior of di-interstitials with different configurations contributes to a better understanding of the self-interstitial atom behavior in tungsten. Despite the inherent difficulty in experimental approaches, atomistic simulation provides an effective means of investigating the defect evolution in materials. In this paper, based on the newly developed interatomic potential for W-W interaction, the diffusion behavior of self-interstitial atoms in tungsten is studied by molecular dynamics simulation. This work focuses on the investigation of the diffusion behavior of di-interstitials with different configurations at different temperatures. The obtained results show that the di-interstitials with the first nearest neighbor configuration presents the one-dimensional migration in the $\left\langle 111 \right\rangle $ direction at temperatures below 1400 K. As the temperature increases, it makes rotations from one $ \left\langle 111 \right\rangle$- to other $\left\langle 111 \right\rangle $-directions. Thus migration of di-interstitial atoms with the first nearest neighbor configuration exhibits a change in mechanism from one-dimensional to three-dimensional migration, keeping the stable $\left\langle 111 \right\rangle $ configuration in the whole investigated temperature range. The migration of di-interstitial atoms with the second nearest neighbor configuration is one-dimensional along the $\left\langle 111 \right\rangle$ direction within a certain temperature range. When the temperature is above 600 K, the di-interstitial atoms will dissociate into two individual self-interstitial atoms and move independently. However, the migrati
Qin Ran, Huan Wang, Rui Zhong, Jian-Chun Wu, Yu Zou, Jun Wang. Diffusion behavior of di-interstitials with different configurations in tungsten[J]. Acta Physica Sinica, 2019, 68(12): 126701-1
Download Citation