The Effect of the Flux B203 and the Role of Ion RE3＊ in CaAI204： Eu2＋, Nd3＋, RE3＋ Phosphor （RE： Dy, Gd, Tb）

The long afterglow phosphors CaA1204： Eu2＋, Nd3＋, RE3＋ （RE： Dy, Gd, Tb） were prepared by the combustion method at 580℃ for 5 min. In this method, the B203 oxide was used as flux. The influences of the flux B203 quantity and the role of ion RE3＋ （RE： Dy, Gd, Tb） in the phosphor CaAI204： Eu2＋, Nd3＋ were studied systemically. The X-ray diffraction pattern, scanning electron microscopy graphic, the photoluminescence spectra and decay time were presented. The emission spectra of phosphors had a broad band with maximum at 444 nm due to electron transition from the 4f65dI to the 4f7 of ion Eu2＋. It is showed that Nd3＋ and RE3＋ ions generated traps that resulted in the long persistent phosphorescence. Simultaneously, when the concentration of RE3＋ ion was high, they generated also emission centers in the phosphor.