Effect of 50 MeV Li~(3+) ion irradiation on electrical, optical and mechanical properties of 4,4'-dimethylbenzophenone

摘要

4,4'-Dimethylbenzophenone (DMBP) single crystals were irradiated at room temperature and at liquid nitrogen temperature with 50 MeV Li~(3+) ions at fluences 1 x 10~(12) and 1 x 10~(13) ions/cm~2. The dielectric constant and dielectric loss as a function of frequency of the applied ac field in the range from 20 Hz to 1 MHz and at temperatures ranging from 313 to 353 K were analyzed. The dielectric constant decreases with increase in frequency for all the temperatures. The dielectric constant and dielectric loss increase with fluence. Optical absorption was measured at different conditions. UV-Vis studies reveal the decrease in bandgap. The unirradiated as well as irradiated crystals were characterized by photolumines-cence. Ion-induced changes were also studied with respect to their mechanical response using the Vick-er's microhardness technique and parameters including fracture toughness, brittleness index and yield strength are calculated.