Synthesis and luminescence properties of nitrided lanthanum magnesium hexaluminate LaMgAl11O19 phosphors

Nitrided LaMgAl₁₁O₁₉ phosphors were prepared by a two-step method involving synthesis at 1550 °C for 4 h, trituration, and firing at 1650 °C for 5 h under a nitrogen atmosphere. Nitrogen was doped into LaMgAl₁₁O₁₉ and bonded with aluminium atoms. The nitrided LaMgAl₁₁O₁₉ phosphors showed plate-like morphology with a rough surface and exhibited strong blue emission at 442 nm and 450 nm, which may be attributed to the energy transition between defect levels. A weak emission band at 590 nm was ascribed to the transition between the V_Al acceptor and the valence band, which was excited at 254 nm.