Synthesis and structure of nanocrystalline mixed Ce–Yb silicates

This work presents results of studies on synthesis and structure of mixed, nanocrystalline Ce–Yb silicates. Using TEM, XRD and FTIR we showed that heat treatment of nanocrystalline Ce1−xYbxO2−(x/2) (x = 0.3, 0.5) mixed oxide supported on amorphous silica in reducing atmosphere, results in formation of Ce–Yb mixed silicates. Dispersion of the oxide on the silica surface and thus a local lanthanide/Si atomic ratio determines the stoichiometry of the silicate. Oxide crystallites uniformly dispersed on the silica surface transformed into A-(Ce1−yYby)2Si2O7 disilicate, while the agglomerated nanoparticles converted into YbyCe9.33−y(SiO4)6O2 oxyapatite silicate as an intermediate phase.