Thermoanalytical investigation of nanocrystalline iron (II) phosphate obtained by spontaneous precipitation from aqueous solutions

Fe3(PO4)2·8H2O has been precipitated under supersaturation conditions from deaerated Fe(NH4)2(SO4)2·6H2O and K2HPO4 aqueous, ethanol–water and iso-propanol–water solutions at pH=6.5 and ambient temperature. The precipitates have been characterised by TG/DTG/DTA and DSC techniques, chemical analysis, BET, and X-ray powder diffraction. The presence of ethanol and iso-propanol in the spontaneous precipitation process of ferrous phosphate leads to highly crystalline powder. Thermal treatment at 500 °C yields a poorly crystalline dehydrated iron phosphate.