Influences of Synthesizing Conditions on the CePO₄ Morphology and Phase Form

The synthesis of precursor of cerium phosphate (CePO₄) by the chemical precipitation method was studied. The effects of different reagents and calcining temperatures on the phase form of products were investigated. The analyses using transmission electron microscopy (TEM) and scanning electron microscopy (SEM), showed that the morphology of preliminary products was needle-like synthesized by H₃PO₄ and CeCl₃ and colloidal by Na₃PO₄ and CeCl₃ at room temperature. Both results of TG-DTA (the thermal gravimetric and differential thermal analysis) and XRD indicate, that the phase form of precursor of CePO₄ synthesized by H₃PO₄ and CeCl₃ change from hexagonal phase to monoclinic phase at about 711.5℃ and from amorphous state to monoclinic phase at about 231℃ when the precursor was synthesized by Na₃PO₄ and CeCl₃.