Site regulation and luminescence properties of Eu3+, Eu2+ in (La, Mg):SrAl12O19 matrix

The partially and equivalent substitution of La + Mg → Sr + Al in SrAl 12 O 19 lattice is an effective strategy to provide trivalent sites, reduce the site occupation splitting of Al and stabilize the entire lattice. When excited by 397 nm, the Eu 3+ activated La, Mg:SrAl 12 O 19 (ASL) phosphor shows intense linear emission through the 5 D 0 → 7 F 4 transition at 707 nm when compared with SrAl 12 O 19 :Eu 3+ . Especially, the Eu, Mg co-doped Sr 1-x La x Mg x Al 12-x O 19 with certain amount of x = 1/3 exhibits the significant intense photoluminescence, which was demonstrated through a lattice evolutional model. Eu 2+ in the host with 1/3 ratio of (La, Mg) substitution shows broad blue emission and as short fluorescence lifetime as 248 ns. The temperature-depended fluorescence quenching behavior confirms the essence of strong electric-phonon coupling originated from distorted and polarized crystal field around Eu 2+ /Sr 2+ site. Basing on site regulation of SrAl 12 O 19 matrix, our study provides a reference for exploration on efficient rare earth ions activated luminescent laser or scintillation materials.