Divalent europium-activated alkaline-earth-metal chlorophosphate luminophores [M5(PO4)3Cl:Eu2+; M=Ca, Sr, Ba] by self-propagating high-temperature synthesis

Abstract

Divalent europium-activated alkaline-earth-metal chlorophosphate luminophores (MCAP:Eu ²⁺ ; M=Ca, Sr, Ba) have been prepared by self-propagating high-temperature (SPHT) synthesis in one pot employing the corresponding nitrates/chlorides, urea and diammonium hydrogen phosphate. The synthesized materials have been characterized by X-ray diffraction, photoluminescent emission spectroscopy, thermogravimetry, scanning electron microscopy and particle size analysis. The formation of chloroapatite depends on the nature of acid used in the combustion mixture. The photoluminescent emission efficiency and particle size distribution are found to depend on the amount of metal chloride used and on the sintering temperature. The results obtained are discussed with respect to the processing method employed.