The influence of some processing conditions on host crystal structure and phosphorescence properties of SrAl 2O 4:Eu 2+, Dy 3+ nanoparticle pigments synthesized by combustion technique

Abstract

The spectroscopic and host phase properties of SrAl 2O 4:Eu 2+, Dy 3+ phosphors with a series of different initiating combustion temperature, urea concentration as a fuel and critical pH of precursor solution are investigated. The SrAl 2O 4:Eu 2+, Dy 3+ nanoparticle pigments were obtained by exothermic combustion process within less than 5 min. The sample that ignited at initiating combustion temperature of 600 °C exhibits highest intensity emission peak at 517 nm in which the SrAl 2O 4 host phase has the maximum fraction of monoclinic SrAl 2O 4 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 SrAl 2O 4:Eu 2+, Dy 3+ 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.