Structural and luminescent properties of LnBaB9O16:Eu3+

Abstract Ln BaB 9 O 16 ( Ln = Y, Gd) and europium-doped materials were synthesized by solid-state reactions. The electron and X-ray diffraction studies show that these compounds crystallize in the rhombohedral crystal system with the lattice constants a = 7.785(2), c = 46.21(1) A for YBaB 9 O 16 and a = 7.809(2), c = 46.47(1) A for GdBaB 9 O 16 . The luminescent spectra of Eu 3+ -doped materials reveal that the local symmetry of the rare earth ions is centrosymmetric in YBaB 9 O 16 and noncentrosymmetric in GdBaB 9 O 16 . The structures of these two compounds are similar and related by symmetry degradation, which occurs at about x = 0.1 in the Y 1−x Gd x BaB 9 O 16 system.