Urea/thiourea induced crystal growth of ammonium nickel sulfate hexahydrate and characterization studiesud

摘要

Single crystals of ammonium nickel sulfate hexahydrate, (NH4)(2)Ni(SO4)(2)center dot 6H(2)O (ANSH), are grown by conventional slow evaporation solution growth technique at room temperature from an aqueous solution containing an excess of urea/thiourea. Structural analysis by single crystal X-ray diffraction analysis reveals that the crystal belongs to monoclinic system with centrosymmetric space group P2(1)/c and the cell parameters are a = 6.246(2) , b = 12.45(4) , c = 9.21(2) , beta = 106.96A degrees. The powder X-ray diffraction and high-resolution X-ray diffraction studies reveal the crystallinity and crystalline perfection of the grown crystal. Optical absorbance spectrum indicates a discontinuous transmission pattern. An increase in dielectric and conductivity parameters with the increase of temperature at all frequencies is observed. Thermal studies reveal that there is no decomposition up to the melting point. Probable mechanism of facile crystal growth of the title compound in the presence of excess urea/thiourea as inducer is analyzed.ud