Study of the damage produced in K[CS(NH2)2]4Br - A non-linear optical single crystal by swift heavy ion irradiation

Pure single crystals of Potassiumtetrakisthioureabromide (KTTB) were irradiated at room temperature with 40 MeV lithium ions at fluences varying from 1010 to 1012 ions/cm2 from the 15 UD Pelletron facility at Inter University Accelerator Centre (IUAC), New Delhi. The pristine as well as irradiated KTTB single crystals were characterized by photoluminescence at room temperature under 2.8 eV blue excitation by a He-Cd laser and UV-Vis absorption to study the radiation induced defects. The ion-induced changes have also been studied with respect to their mechanical response using Vickers micro hardness technique. The effect of swift heavy ion beam on dielectric dispersion is explained in detail. Surface morphology was also studied for pristine and irradiated crystals.