Track evolution observed in NiO exposed to swift heavy ion irradiation

In this study, the track evolution in single crystal Nickel Oxide (NiO) exposed to Swift Heavy Ion (SHI) irradiation has been studied using electron microscopy techniques. Scanning Transmission Electron Microscopy (STEM) was utilized to interrogate the microstructure of the latent tracks formed in both low fluence (non-overlapping regime) and high fluence (overlapping regime) specimens. Ion energies used were 593 MeV and 1.6 GeV, while fluences ranged from 1.0×10¹¹ ions/cm² to 1.4×10¹⁴ ions/cm². Electron Energy Loss Spectroscopy (EELS) was used to determine the chemical composition of the 'tracks' seen in high fluence samples. Elevated levels of Oxygen suggest radiolytic decomposition of NiO into O₂ during SHI bombardment. (authors)