Structure of medium temperature phase beta-LaSc3( B03)4` crystal

摘要

The compound beta-LaSc3(BO3)4, crystallizes in the rhombohedral with space group R32 and cell paraps- eters a=9.819(3), c=7.987(l) A, Z=3, V=666.5(3) A3 Dc=3 .80 g/cm3, lambda(MoKa)=0.7 1067 A, F(000)=705, final R=0.053. Rw=0-072 for 512 observed reflection with 1> = 3 dlta(I). The La atoms, Sc atoms and B atoms occupy trigonal prisms, octahedra and planar triangle of oxygen, respectively. The isolated LaO6 trigonal prisms alternate along the c-axis with BO3 triangle (B( l )) that are perpen- dicular to the c-axis. La3+ ions join by means of La-O- Sc(B)-O-La with the distance between La3+ ions being 6.263 A. This structural characteristic will result in a weaker interaction between Nd3+ ions and a lower fluo- rescence concentration quenching effect.