Growth and characterization of BTCS and BTZA crystals grown by slow evaporation method

Good quality Bisthiourea Cadmium Sulphate (BTCS) and Bisthiourea Zinc Acetate (BTZA) crystals have been grown by simple slow evaporation method. From the powder X-ray diffractograms it is found that BTCS crystal belongs to orthorhombic system, whereas BTZA crystal belongs to Tetragonal system. The FTIR analysis reveals that the CS stretching frequencies of both BTCS and BTZA shows a shift to lower frequencies when compared to pure thiourea, which may be attributed to the reduced double bond character of CS bond on coordination. UV–vis spectroscopic studies show that the grown crystals have high transparency in entire visible region and NIR region. The hardness of the crystals have been studied using Vicker's microhardness test and it was found that the BTZA crystals show better hardness when compared to BTCS crystals.