Effect of gamma and neutron irradiation on structural and optical properties of ammonium dihydrogen phospate single crystals

The nonlinear optical single crystals of ammonium dihydrogen phosphate (ADP) were grown by slow evaporation solution growth technique at ambient temperature. The grown crystals were exposed to neutron beam of energy 4.44 MeV and flux 2.2 × 107 ncm−2s−1 irradiated for 3hr and 5hr and Co-60 gamma radiation of doses 50 kGy and 100 kGy separately. The structural, optical, and nonlinear optical properties (second harmonic generation) of the crystals were investigated before and after irradiation. X-ray diffraction studies reveal that the compressive strains are generated in the irradiated crystals. The UV-visible spectra shows that the optical absorption increases with increase in radiation dose. The R.I of the crystal was found to decrease after neutron irradiation, whereas it increases with the increase in the gamma dose rate. Except at high dose rate, SHG efficiency of ADP is unaffected by either gamma or neutron irradiation.