Nanocrystalline luminescent Eu3+-doped Y2SiO5 prepared by sol-gel technique

The effect of the trivalent europium ion concentration upon the structure and luminescence properties of nanocrystalline luminescent Eu3+:Y2SiO5 prepared by sol-gel method is investigated. In all the samples treated at 1100 degrees C, monoclinic X-1, is the dominant phase for all europium concentrations, accompanied by cubic yttria and an hexagonal phase of yttrium oxide silicate phase (apatite, Y-4.67(SiO4)(3)O). The content of the less abundant phases increases with europium concentration at the expenses of the X-1 phase. The room temperature laser-excited luminescence spectra, excited at 488.0 nm, consist of 4f-4f emission transitions from 5 Do excited level of the Eu ions to the F-7(0), F-7(1), F-7(2), F-7(3) and F-7(4) levels. The intensity of the bands regularly increases with europium content and at the highest europium content the concentration quenching is not observed, differently from bulk samples