1. Structural integrity and damage of ZrB2 ceramics after 4 MeV Au ions irradiation.
- Author
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Bao, Weichao, Robertson, Stuart, Zhao, Jia-Wei, Liu, Ji-Xuan, Wu, Houzheng, Zhang, Guo-Jun, and Xu, Fangfang
- Subjects
ZIRCONIUM boride ,ELECTRON energy loss spectroscopy ,CONDUCTION electrons ,TRANSMISSION electron microscopes ,ELECTRON spectroscopy ,IRRADIATION ,MELTING points - Abstract
[Display omitted] • Ion irradiation of ZrB 2 leads to boron vacancies evidenced experimentally and quantified by DFT calculation. • Ion irradiation of ZrB 2 leads to lattice line defects as long dislocations and Frank dislocations. • ZrB 2 keeps structural integrity with mild damage at lattice level after ion irradiation. Ultra-high temperature ceramics have been considered as good candidates for plasma facing materials due to their combination of high melting point, high strength and hardness, high thermal conductivity as well as good chemical inertness. In this study, zirconium diboride has been chosen to investigate its irradiation damage behavior. Irradiated by 4 MeV Au
2+ with a total fluence of 2.5 × 1016 cm−2 , zirconium diboride ceramic shows substantial resilience to irradiation-induced damage with its structural integrity well maintained but mild damage at lattice level. Grazing incident X-ray diffraction evidences no change of the hexagonal structure in the irradiated region but its lattice parameter a increased and c decreased, giving a volume shrinkage of ∼0.46%. Density functional theory calculation shows that such lattice shrinkage corresponds to a non-stoichiometric compound as ZrB 1.97. Electron energy-loss spectroscopy in a transmission electron microscope revealed an increase of valence electrons in zirconium, suggesting boron vacancies were indeed developed by the irradiation. Along the irradiation depth, long dislocations were observed inside top layer with a depth of ∼750 nm where the implanted Au ions reached the peak concentration. Underneath the top layer, a high density of Frank dislocations is formed by the cascade collision down to a depth of 1150 nm. All the features show the potential of ZrB 2 to be used as structural material in nuclear system. [ABSTRACT FROM AUTHOR]- Published
- 2021
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