Kinetics of ion-beam damage in lithium niobate

The damage kinetics induced by irradiation with a diversity of swift ions (O at $5MeV$⁠; F at $5.1MeV$⁠; Si at 5, 7.5, and $41MeV$⁠; and Cl at 11 and $46MeV$⁠) has been investigated in the range of $1012–1015at.∕cm2$⁠. It covers from the initial stage where single damage tracks are isolated and well separated, up to the stage where a full amorphous layer is produced. The damage is characterized by the areal fraction of disorder derived from the Rutherford backscattering∕channeling spectra. The data approximately fit an abrupt Avrami-type dependence with fluence. The fluence value at which 50% of the sample surface becomes disordered shows a clear increasing trend with the electronic stopping power of the ion. The trend is consistent with Monte Carlo simulations based on a recent model for defect creation. Moreover, the quantitative agreement for the defect generation rate appears also reasonable.