LATENT TRACK FORMATION IN LINBO3 SINGLE-CRYSTALS IRRADIATED BY GEV URANIUM IONS

Single crystals of LiNbO3 (Y-cut orientation) have been irradiated at GANIL with U-238 ions using three different energies: 0.84, 2.01 and 2 .73 MeV/a. All the irradiations were performed at room temperature, up to a fluence of 4 x 10(11) ions.cm(-2). The lattice disorder resultin g from the high electronic stopping power (between 28 and 40 keV/nm) h as been characterized by Rutherford backscattering spectrometry in cha nneling geometry (RBS-C), in conjunction with high resolution transmis sion electron microscopy (HRTEM). According to RBS-C analysis, the dam age cross-section od depends on the electronic stopping power of the i ncident ions and a velocity effect is observed. HRTEM observations sho w a damage morphology consisting mainly of cylindric amorphous zones ( latent tracks) having a mean core radius of about 2 Mn.