Real-time evolution of ion–surface interactions of MgAl2O3 and LiNbO3 detected by ion-induced photon spectroscopy

Ion-induced photon emission under 60 keV Cu^? implantation into the insulators of MgAl₂O₄ and LiNbO₃ was in situ measured over a wide wavelength range from 200 to 900 nm. The formation of the Mg and Li deficient layers for the respective insulator was detected based on the dose dependence of the Al, Mg and Li atomic line intensities. The Al I and Mg I line intensities from spinel exhibit different behaviors depending on irradiation temperatures: they gradually decrease while the (Al I)/(Mg I) ratio increases up to dose of 3×10¹⁷ ions/cm² at room temperature or exhibits a steady-state tendency at high temperature. Sharp decrease of Li I line intensity from LiNbO₃ under high dose rate bombardment indicates drastic changes of surface layer that may alter the phase stability and optical performance of insulators.