A new crystal of ammonium cobalt nickel sulfate hexahydrate for UV light band-pass filter

A new crystal material for UV light band-pass filter, ACNSH (ammonium cobalt nickel sulfate hexahydrate) was composed and its crystal structure was studied by X-ray diffraction method. The empirical composition of the title compound is (NH4)2Co0.17Ni0.83(SO4)2 · 6H2O with formula weight 395.15. ACNSH structure belongs to monoclinic space group P2(1)/c, crystal parameters a = 6.2432(3) Å, b = 12.4728(5) Å, c = 9.1967(4) Å, α = γ = 90°, β = 106.9880(10)°, V = 684.90(5) Å3, Z = 2, and Dc = 1.916 g/cm3. Solubility of ACNSH in water was determined and large, dark-green crystals with sizes up to 18 × 19 × 45 mm3 have been grown by cooling solution method. Optical transmission spectra reveals that ACNSH has low band at 450–600 nm. Thermo-gravimetric analysis showed that the dehydration temperature of ACNSH is about 97 °C. The relationship between the structural constituents and optical transmission properties is discussed.