SYNTHESIS, OPTICAL AND THERMAL PROPERTIES OF SEMIORGANIC NONLINEAR OPTICAL CRYSTALS GROWN BY SOLUTION GROWTH SLOW EVAPORATION TECHNIQUE

摘要

Bisthiourea potassium chloride, a new semiorganic nonlinear optical crystal, has been grown by solution growth slow evaporation technique for the first time. The grown crystal were characterised by recording the powder X - ray diffraction and it verified by using single XRD. The presence of functional groups was confirmed by using fourier transform infrared (FTIR) analysis. Optical behaviour such as UV - Vis - NIR absorption spectrum was carried and the UV cut-off wavelength for the grown crystal is at 260 nm. Thermal analysis was carried out to determine the thermal stability and the melting point of the grown crystal using TG/DTA. Second - Harmonic generation were investigated to explore nonlinear optical characteristics of the materials using Kurtz powder technique.