Crystal structure of SrAl2B2O7 and Eu2+ luminescence

The crystal structure of strontium dialuminodiborate SrAl2B2O7 has been est ablished by single-crystal X-ray diffraction methods. The compound crystall izes in the trigonal system (space group R (3) over bar c, Z = 6) with cell parameters a = 4.893(1) Angstrom and c = 47.78(1) Angstrom. Aluminium and boron atoms are, respectively, in tetrahedral and triangular oxygen coordin ation, The assembly of Al2O7 units and BO3 triangles forms double layers be tween which Sr2+ ions are located. The Eu2+-doped crystalline powder exhibi ts a luminescence band with maximum at 415 nm, Luminescence characteristics are compared to those of other strontium berates. (C) 2000 Academic Press.