Solid combustion wave with two successive reactions to produce phosphor powders

Abstract

A solid combustion approach consisting of two successive reactions is developed for producing metal oxide (Y3Al5O12:Ce3+), silicate (Zn2SiO4:Mn2+), and borate (YBO3:Eu3+) phosphor powders. The typical precursors for the phosphor synthesis were the corresponding metal oxides. The entire combustion process was driven by a KClO3 + CO(NH2)(2) exothermic mixture preliminarily admixed with precursor oxide powders. Small amounts of NH4F were also used to accelerate the phosphor formation and crystallization processes. The optimal synthesis temperatures estimated from the temperature distributions were between 700 and 1200 degrees C. and the combustion velocity varied from 0.04 to 0.5 cm/s. From the synthesis, well-dispersed phosphor microparticles with a controlled morphology were obtained. The roles of the KClO3 + CO(NH2)(2) exothermic reaction and the NH4F additive were examined in the context of the reaction mechanism and the phosphor powder characteristics. The obtained combustion-synthesized phosphors were of high quality and single phase having high luminescence characteristics. (C) 2012 Elsevier B.V. All rights reserved.