Europium(III)-doped A(2)Hf(2)O(7) (A = Y, Gd, Lu) nanoparticles: Influence of annealing temperature, europium(III) concentration and host cation on the luminescent properties

Abstract

The detailed analyses of structure and luminescence of europium(III)-doped A(2)Hf(2)O(7) (A = Y, Gd, Lu) nanoparticles is presented. Samples were prepared by time and cost effective combustion method that utilize polyethylene glycol both as a chelating agent and as a fuel, with different europium(III) concentrations (from 1 to 12 at.%), annealed at temperatures ranging from 800 to 1400 degrees C, and with alternating A(3+) cation in the A(2)Hf(2)O(7) host. Then, structural variations between materials were analysed by Xray diffraction and structural refinement, while the changes in the luminescence were assessed from the Judd-Ofelt analyses of emission spectra. Nanoparticles prepared at the lowest temperature (800 degrees C) had the smallest particle size of similar to 6 nm and showed the highest quantum efficiency when doped with 1 and 2 at.% of europium(III). Radiative transition rate and quantum efficiency of emission showed Lu2Hf2O7 GT Gd2Hf2O7 GT Y2Hf2O7 trend. (C) 2016 Elsevier B.V. All rights reserved.