Luminescence and EPR investigations of Mn activated calcium aluminate prepared via combustion method

Luminescence investigations of Mn-activated calcium aluminate phosphors prepared using the combustion method are described. An efficient phosphor can be prepared by this method at reaction temperatures as low as 500 °C in a few minutes without the need for any further calcination. The phosphor has been characterized by powder X-ray diffraction, scanning electron microscope. Optical properties were studied by photoluminescence spectra. Photoluminescence studies of the prepared phosphors showed prominent red emission from Mn4+ ions, while EPR investigations indicated the presence of Mn2+ as well as Mn4+ ions in the prepared phosphors. EPR spectra of the phosphor samples suggest that Mn ions occupy distorted lattice sites in the phosphors.