Synthesis and structure of nanocrystalline mixed Ce–Yb silicates

• New method of synthesis of nanocrystalline mixed lanthanide silicates is proposed.
• Formation of A-type (Ce1−yYby)2Si2O7 in well dispersed Ce1−xYbxO2−(x/2)–SiO2 system.
• Formation of YbyCe9.33−y(SiO4)6O2 in agglomerated Ce1−xYbxO2−(x/2)–SiO2 system.

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.

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