Darstellung und Kristallstruktur der ternären Boride SrNi12B6 und BaNi12B6

Abstract

Abstract The crystal structures of the newly prepared ternary borides SrNi12B6 and BaNi12B6 have been determined by single-crystal X-ray methods and refined to R-values of 0.031 and 0.052 respectively. Both compounds crystallize in space group R[unk]m–D5 3d with lattice constants a = 959.0 pm, c = 745.5 pm, Z = 3 for SrNi12B6 and a = 968.9 pm, c = 747.0 pm, Z = 3 for BaNi12B6. The structure contains isolated boron atoms, surrounded by distorted trigonal prisms of Ni atoms with one additional Ni upon one of the faces. The prisms are arranged in connected layers consisting of six- and three-membered rings. Of the compounds SrNi2B2, BaNi2B2, and Ba2Ni9B6 lattice constants are reported.