Photoluminescence and EPR investigation of combustion Synthesized BaAl2O4:Cr3+

Recently aluminate materials have been extensively studied as phosphors for the next generation of display and lighting lighting devices. Synthesis of aluminate oxide phosphors has been achieved by a variety of routes; solid-state reactions, sol-gel techniques, microwave processing, hydrothermal synthesis and combustion synthesis. In the present investigation, we have successfully employed low temperature combustion method for the preparation of BaAl2O4:Cr3+. Powder X-ray diffraction analysis was used to characterize the as-prepared combustion products, while the optical properties were studied using photoluminescence. The morphological aspect of the resulting powders, while the optical properties were studied microscopy, which showed crystallites with irregular morphology in the form of plates. PL excitation spectrum revealed two broad intense bands located at 421 nm and 55nm due to Cr3+ ions, while emission spectrum showed peaks due to Cr3+ ions broad intense bands located at 421 nm and 552 nm due to Cr3+ ions, while emission spectrum showed peaks due to Cr3+ ions at 705 nm. EPR spectrum of undoped BaAl2O4 showed signals attributable to unintentional Fe3+ impurity ions, while EPR spectrum of BaAl2O4:Cr3+ contained an additional signal around 3450G, corresponding to g congruent to 1.98, typical of Cr3+ ions.