The influence of some processing conditions on host crystal structure and phosphorescence properties of SrAl2O4:Eu2+, Dy3+ nanoparticle pigments synthesized by combustion technique

The spectroscopic and host phase properties of SrAl2O4:Eu2+, Dy3+ phosphors with a series of different initiating combustion temperature, urea concentration as a fuel and critical pH of precursor solution are investigated. The SrAl2O4:Eu2+, Dy3+ nanoparticle pigments were obtained by exothermic combustion process within less than 5 min. The sample that ignited at initiating combustion temperature of 600 degrees C exhibits highest intensity emission peak at 517 nm in which the SrAl2O4 host phase has the maximum fraction of monoclinic SrAl2O4 phase. The excitation spectra consist of 240 and 254 nm broad peaks. The experimental results show that the optimum ratio of urea is 2.5 times higher than theoretical quantities for best emission condition of SrAl2O4:Eu2+, Dy3+ phosphor particles. The critical pH was obtained about 5.2. The crystallite size of these pigments is about 40 nm before thermal treatment and 62 nm after thermal treatment, respectively. Crown Copyright (C) 2009 Published by Elsevier B.V. All rights reserved.