Energy transfer from Tb3+ to Mn2+ in LaMgAl11O19:Tb, Mn phosphors

Luminescent properties of LaMgAl11O19:Tb, Mn phosphors were investigated. It was observed that the energy distributions of the Tb3+-emission bands associated with transitions from the 5D3 and 5D4 levels to 7FJ depend on the Tb3+-concentration, which is due to the cross-relaxation between Tb3+ ions. The emission band at about 516 nm is attributed to the 4T1 → 6A1 transition of the Mn2+ ions. We observed an energy transfer from the Tb3+ to Mn2+ ions in LaMgAl11O19:Tb, Mn. The energy transfer process may involve the 5D3 level of the Tb3+ ions and the 4T2 and 4T1 level of the Mn2+ ions.