Nanocrystalline Eu3+ doped-yttrium oxide dispersed onto silica prepared by a deposition–precipitation method

A deposition-precipitation technique was successful for the obtainment of Eu 3+ doped-yttria/silica nanocomposites. The method is based on the impregnation of mesoporous commercial silica with a solution of yttrium and europium nitrates in the presence of urea. Urea slow hydrolysis implies the gradual deposition of yttrium-europium hydroxides onto silica. Y 2 O 3 crystalline particles, with mean size of 7.5 nm, form over the silica matrix after calcination of the impregnated system at 900 °C, as evidenced by XRD and TEM. The nanoparticles slightly interact at the interface with silica, as revealed by 29 Si NMR/MAS spectroscopy. At 1000 °C the composite evolves toward the formation of Y 2 Si 2 O 7 crystalline phase.