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. (c) 2005 Published by Elsevier B.V.