Synthesis of Nanocrystalline Ca_0.6Mg_0.4Zr₄(PO₄)₆ by Co-precipitation Method

Nano-sized Ca0.6Mg0.4Zr4(PO4)6(C0.6M0.4ZP)powders were successfully synthesized by phosphate chemical co-precipitation method using stoichiometric Ca(NO3)2·4H2O,Mg(NO3)2·6H2O,ZrOCL2·8H2O and NH4H2PO4 as raw materials.The effect of processing conditions such as solution pH values,reactant concentrations and adding order of reactant on phase composition,mean particle size and particle size distribution of C0.6M0.4ZP nano-powders were investigated by means of TG-DSC,XRD,Nano particle size/Zeta potential analysis and TEM.The results show that single phase C0.6M0.4ZP nano-powders can be obtained when the mixed Ca2+,Mg2+,Zr4+ solutions are added into NH4H2PO4 precipitation agent solutions,controlling the pH values of NH4H2PO4 solutions between 3 to 11 and after the thermal processing of precipitation at 900℃ for 3 h.With 0.5 mol/L Zr4+ and 1.0 mol/L NH4H2PO4,the mean particle size and particle size distribution of resultant C0.6M0.4ZP is smaller at pH=9 than those at other pH values,and were 40nm and 20-70 nm,respectively.