Luminescence of Mn2+ in SrGa12O19, LaMgGa11O19, and BaGa12O19

Lattice parameters are given of SrGa12O19, BaGa12O19, and LaMgGa11O19, three new gallates with the magnetoplumbite structure. The luminescence of the compounds without and with activation by Mn2+ is reported. The quantum efficiencies of the Mn2+ phosphors are between 15% (BaGa12O19:Mn) and 70% ({Sr1−xLax}Ga12−xMgxO19:Mn). The emission strongly resembles that of Mn2+ in MgGa2O4. The fine structure of the Mn2+ emission band at 77°K is due to phonon coupling.