Large size single crystals of SO4have been successfully grown by a hydrothermalprocess at 160℃for 24h, using CuSO4·5H2O, ethylene diamine and reductive Zn powder as reactants. The diameters of the single crystals are range from 0.5mm to 1mm, and lengths reach up to 20mm. The single crystals were characterized by XRD analysis, FTIR and UV Vis spectrum absorption measurements. The single crystal was confirmed to beSO4 by performing powder diffraction of the single crystal. X ray diffraction of the single crystals shows (100) face to be cleavage face. The diffraction peaks are sharp and rockingcurve for 200 diffraction has a narrow FWHM (the full width at half maximum), which indicate the single crystal of SO4 is perfect with less lattice distortion and defects. The single crystal appears transparent,and has constant weak absorption in UV Vis spectrum region,whichcould be used as a novel optical crystal material.
