Structure of High Temperature Phase α-Ba_3Y(BO_3)_3 Crystal

The high temperature phase a-Ba3Y(BO3)3 was synthesized by Czochralski method, and its crystal structure has been determined by single-crystal X-ray diffraction. It crystallizes in the trigonal system, space group 3R with a = 13.028(2), c = 9.4992(2) ? V = 1396.1(5) ?, Ba3YB3O9, Mr = 677.36, Z = 6, Dc = 4.834 g/cm3, l(MoKa) = 0.71073 ? m = 18.721 mm-1, F(000) = 1764, the final R = 0.0718 and wR = 0.1640 for 1199 observed reflections with I 2s(I). In this structure two alternate nonequivalent Y atoms form one-dimensional chains bridged by the Ba atoms with BO3 triangles which link Y(1) and Y(2), respectively. The Ba atom is surrounded by nine O atoms belonging to six BO3 triangles.