Crystal growth and characterization of K[CS(NH2)2]4Br--A semiorganic non-linear optical crystal

This paper presents the synthesis and crystal growth of optically non-linear semi-organic crystal potassiumtetrakisthioureabromide (KTTB) using water and a mixture of acetone and water (1:1) by slow evaporation of aqueous solution at room temperature. The solubility has been determined in both the solvents at various temperatures. The compound crystallizes in non-centrosymmetric space group P41. The crystalline perfection of the grown crystals has been analysed by high-resolution X-ray diffraction measurements. The IR and polarized Raman spectra have been interpreted using both the factor group analysis. The results of the correlation field splitting of the thiourea internal vibrations are discussed. The optical characterization of the crystal shows the cut off wavelength near the UV region. Also the crystal shows good propensity to emit second harmonic generation of Nd:YAG laser.