The crystal structure and luminescence of Ce3+, Tb3+ and Eu3+ in KBaLn3+(BO3)2 [Ln3+ = Sc, Y, Lu, Gd]

Abstract The structure of KBaLn 3+ (BO 3 ) 2 [Ln 3+  = Sc, Lu, Gd] was solved by Rietveld refinement of the powder X-ray diffraction data. The materials crystallize with the mineral Buetschliite [K 2 Ca(CO 3 ) 2 ] structure. The lattice parameters of KBaLn 3+ (BO 3 ) 2 [Ln 3+  = Sc, Lu, Gd] increased with increasing ionic radius of the Ln 3+ cation. In this structure, the Ln 3+ cations are octahedrally coordinated. The phase formation region is dependent on the ionic radii of the Ln 3+ cation. The optical properties of Ce 3+ , Tb 3+ and Eu 3+ and their dependence on the host lattice composition are investigated and discussed. It is noteworthy that the optical properties of these ions are independent of the Ln 3+ cation in KBaLn 3+ (BO 3 ) 2 . It is concluded that in this family of materials, the crystalline field strength and the covalence at the rare earth site is independent of the host lattice composition.