Growth, structural, optical, electrical and SHG studies of N-N′ allylthiourea doped KDP single crystals

摘要

Potassium Dihydrogen Phosphate (KDP) crystals are one of the most popular crystals used for Non-linear Optical (NLO) applications. Pure KDP single crystals and KDP crystals doped with N-N′ allylthiourea were grown by the method of slow evaporation from aqueous solutions. The grown pure and doped crystals were confirmed by X-ray single crystal and powder diffraction studies. The pure and doped crystals were characterized by FTIR spectroscopy studies. Absorptions of these grown crystals were analyzed using UV–Vis–NIR studies, and it was found that these crystals possess minimum absorption in the entire visible region. Nonlinear optical studies of pure and doped crystals were carried out and it reveals that the dopants have increased the efficiency of KDP crystals. Dielectric measurements were carried out along both the unique axis and perpendicular directions at various temperatures ranging from 40 to 150 °C. The dielectric constant and the dielectric loss values of N-N′ allylthiourea doped KDP crystals were lower than the pure KDP crystals. Also, it indicates that 0.8 mole% N-N′ allylthiourea addition to KDP leads to low permittivity value dielectrics. The results are discussed.