Abstract: The fluorescence of Eu²⁺ and Mn²⁺ coactivated Sr₃MgSi₂O₈ was studied.The emission bands of Eu²⁺ and Mn²⁺ peaking at 460 nm and 690 nm are originated from 5d-4f transition of Eu²⁺ and ⁴T₁, (⁴G)-⁶A_1g(⁶S) transition of Mn²⁺ respectively.The fluorescence of Mn²⁺, singly doped in Sr₃MgSi₂O₈ has not been observed.However, codoping with Eu²⁺makes photoluminescence of Mn²⁺ apPear at 690 nm.This shows that the emission of Mn²⁺is sensitized by Eu²⁺, and then the fluorescence lifetime of Eu²⁺ is affected by Mn²⁺.The ex-perimental results indicate that there exists an effective energy transfer from Eu²⁺ to Mn²⁺ in Sr₃MgSi₂O₈ host.This kind of energy transfer is due to the electric dipole-dipole interaction of the resonance transfer.

Key words: Luminescence, Energy transfer, Fluorescence lifetime