DAMAGE-INDUCED IN LINBO3 SINGLE-CRYSTALS BY GEV GADOLINIUM IONS

Single crystals of LiNbO3 with two different orientations (Y-cut and Z-cut) have been irradiated at GANIL with 5.17 MeV/amu Gd-155 ions at room temperature. The fluence extended from 1.5 x 10(11) to 1.2 x 10(12) 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 degrador, the defect efficiency has also been investigated as a function of the electronic stopping power (18 keV/nm < (d E/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 approximation 8.5 x 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.