Damage induced in LiNbO3 single crystals by GeV gadolinium ions

Abstract

Single crystals of LiNbO3 with two different orientations (Y-cut and Z-cut) have been irradiated at GANIL with 5.17 MeV/amu 155Gd ions at room temperature. The fluence extended from 1.5 × 1011 to 1.2 × 1012 ions cm−2. The damage resulting from the high electronic stopping power (up to 30 keV/nm) has been characterized by both Rutherford backscattering ion channeling (RBS-C) and optical absorption measurements. By using a dégrader, the defect efficiency has also been investigated as a function of the electronic stopping power (18 keV/nm < (dE/dx)e < 30 keV/nm). The results show a defect creation by ionization process and for the highest electronic stopping powers a damage cross section of ∼ 8.5 × 10−13 cm2, corresponding to a mean track radius of about 5 nm. Surface swelling of the irradiated surfaces was measured using a surface profilometer and the height of the out-of-plane step was correlated with the damage induced by the high electronic energy losses.