Crystal structure and luminescence properties of a novel promising phosphor Ba3ScB9O18

A novel borate compound Ba 3 ScB 9 O 18 has been synthesized by solid-state reaction and its structure has been determined and refined from powder X-ray diffraction data. This compound crystallizes in a hexagonal cell (space group P 6 3 / m ) with lattice parameters a =7.1360(4) Å and c =16.5420(9) Å, and each unit cell contains two formulas. Its crystal structure is made up of planar B 3 O 6 groups parallel to each other along the [001] direction, regular ScO 6 octahedra, irregular BaO 6 hexagons, and BaO 9 polyhedra to form an analogue structure of Ba 3 YB 9 O 18 . DTA and TGA curves for Ba 3 ScB 9 O 18 show that it is a chemically stable and congruent melting compound. Luminescence properties for Ba 3 ScB 9 O 18 were investigated using fluorescence spectroscopy and X-ray excited luminescence measurements. Its emission spectrum upon UV excitation (330 nm) has exhibited a prominent blue-green emission band at about 490 nm, and its XEL spectra show an intense emission band in the range of 360 to 500 nm with peak center at 400 nm. The light yield of Ba 3 ScB 9 O 18 powders is about 23% as large as that of BGO powders under the same measurement conditions. There seems to be a certain relationship between the scintillation properties and the structural features of Ba 3 ScB 9 O 18 .