High-content bulk doping and thermal stability of rare earth ions in CeO2 nanocrystals

Monodisperse Eu3+:CeO2 nanoparticles 5–8 nm in size were prepared by a facile solvothermal route. A high content of Eu3+, up to 20.0 mol.%, is shown to incorporate into the CeO2 lattice. Upon heating from 600 to 800 °C, the incorporation of Eu3+ in CeO2 nanocrystals is basically stable for the sample with relatively low doping content; however, Eu3+ ions are partially expelled from the lattice to the surfaces of the CeO2 nanocrystals when the doping content is high.