Preparation of LaPO4 Nanoparticles by Coprecipitation Method

LaPO4 nanopowders were prepared by co-precipitation method using NH4H2PO4 and La(NO3)3 as raw materials. The influence of the composition of raw materials and the heat treatment process on the composition and microstructure of the synthesized powders were investigated by thermogravimetric-differential scanning calorimetry, X-ray diffraction and transmission electron microscopy. The synthesis mechanism of LaPO4 powder was discussed. The results showed that the precipitate prepared using NH4H2PO4 and La(NO3)3 with mole ratio of 1:1 was hexagonal LaPO4·0.5H2O, and it transformed into hexagonal LaPO4 after calcination at 400 °C. The precipitate calcined at 900 °C was not well crystalized monoclinic LaPO4, and it crystalized completely with particle size about 200 nm after calcination at 1000 °C.