Luminiscent properties of a new long afterglow Eu²⁺ and Dy³⁺ activated Ca₃MgSi₂O₈ phosphor

Long afterglow Ca₃MgSi₂O₈: Eu,Dy phosphor with high brightness and long afterglow was firstly prepared at high temperature and weak reductive atmosphere. 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 4f-5d transitions of Eu²⁺, which is in good agreement with the calculated value 467.7 nm with the relation E=Q[1-(V/4)^1/V10^-(n.ea.r)/8], and implied that luminescent centers Eu²⁺ occupied the octa-coordinated Ca²⁺ sites in the Ca₃MgSi₂O₈ host. The decay graph indicated that this phosphor also contains fast-decay and slow-decay process, which can last over 5 h in the limit of the light perception of the dark-adapted human eye (0.32 mcd/m²).