Structural integrity and damage of ZrB2 ceramics after 4 MeV Au ions irradiation

Ultra-high temperature ceramics have been considered as good candidates for plasma facing materials due to their combination of high melting point, strength and hardness, thermal conductivity well chemical inertness. In this study, zirconium diboride has chosen investigate its irradiation damage behavior. Irradiated by 4 MeV Au2+ with a total fluence 2.5 × 1016 cm?2, ceramic shows substantial resilience irradiation-induced structural integrity maintained but mild at lattice level. Grazing incident X-ray diffraction evidences no change the hexagonal structure in irradiated region parameter increased c decreased, giving volume shrinkage ?0.46%. Density functional theory calculation that such corresponds non-stoichiometric compound ZrB1.97. Electron energy-loss spectroscopy transmission electron microscope revealed an increase valence electrons zirconium, suggesting boron vacancies were indeed developed irradiation. Along depth, long dislocations observed inside top layer depth ?750 nm where implanted Au ions reached peak concentration. Underneath layer, density Frank is formed cascade collision down 1150 nm. All features show potential ZrB2 be used material nuclear system.