Luminescent properties of a new long afterglow EU2+ and Dy3+ activated Ca3MgSi2O8 phosphor

Long afterglow Ca3MgSi2O8:Eu,Dy phosphor with high brightness and long afte rglow was firstly prepared at high temperature and weak reductive atmospher e. The excitation and emission spectra of this phosphor showed that both of them are broad band, and the main emission peaking at 475.5 nm is due to 4 f-5d transitions of Eu2+, which is in good agreement with the calculated va lue 467.7 nm with the relation E= Q[1-(V/4)(1/V)10(-(n.e.a.r)/8)], and impl ied that luminescent centers Eu2+ occupied the octa-coordinated Ca2+ sites in the Ca3MgSi2O8 host. The decay graph indicated that this phosphor also c ontains fast-decay and slow-decay process, which can last over 5 h in the l imit of the light perception of the dark-adapted human eye (0.32 mcd/m(2)). (C) 2001 Elsevier Science Ltd. All rights reserved.