Cerium and terbium luminescence in LaMgAl11O19

Under 254 nm excitation LaMgAl₁₁O₁₉ : Ce³⁺ shows emission peaking between 340 and 360 nm with a quantum efficiency up to 65%, which is almost independent of the Ce³⁺ concentration. Energy transfer between the Ce³⁺ ions is not efficient. In CeMgAl₁₁O₁₉ : Tb³⁺ efficient energy transfer occurs from Ce³⁺ to Tb³⁺, resulting in a green emission with a quantum efficiency up to 65%. The Ce³⁺ - Tb³⁺ energy transfer is ascribed to electric dipole-quadrupole interaction.