Thermal analytical study of different phases of potassium hexacyanoferrate(II) crystal -: Effects of growth conditions, heat treatment and γ-irradiation on the unit cell parameters

The unit cell parameters of virgin and thermally treated potassium hexacyanoferrate(II)trihydrate (KFCT) crystals are measured at room temperature. Considerable changes in the lattice constants are observed for as-grown or pre-cooled to the liquid nitrogen temperature samples after heating up to selected higher temperatures for different times. The detected variations may be due to partial or total removal of the three water molecules of crystallization and the transformation of Fe2+ to Fe3+. DSC, DTA and TG are used to study physical and chemical changes associated with the observed crystallographic variations. The effect of gamma-irradiation with a dose of 5 center dot 10(5) Gy on the crystal structure of KFCT is also examined. Two computer software programs are used to analyze the data of the X-ray diffraction patterns and the results are compared.