Synergistic effects of nuclear and electronic energy deposition on damage production in KTaO3

Ion irradiation of KTaO3 has been performed to investigate the evolution of irradiation damage with and without significant electronic energy deposition. Damage accumulation under irradiation with 2 MeV Au ions follows a direct-impact/defect-stimulated model, and occurs more rapidly than in SrTiO3 under similar conditions. Electronic energy deposition from 21 MeV Ni ions creates negligible damage in pristine KTaO3 to depths of 1 micron; however, damage is greatly enhanced in samples containing pre-existing defects, as evidenced by rapid amorphization due to track formation. The cross-sections for amorphous tracks show a nearly linear dependence on initial disorder, comparable with SrTiO3.