Synthesis, structure, and superconductivity in Be1.09B3

Julia Y. Chan, Louisiana State University
Frank R. Fronczek, Louisiana State University
D. P. Young, Louisiana State University
J. F. DiTusa, Louisiana State University
P. W. Adams, Louisiana State University


The compound Be1.09B3 was prepared by arc-melting of the elemental constituents. The structure of single crystals taken from the arc-melted botton was determined from single-crystal X-ray data (T = 120 K) and is hexagonal, having space group P6/mmm, and lattice parameters a = 9.7738(7) Å and c = 9.5467(6) Å, R = 0.047. The structure consists of a hexagonal array of boron icosahedra, nonicosahedral B12 cages, and B18 cages. Stacked hexagonal layers of boron atoms, hexagons formed by B and Be, and equilateral triangles of boron atoms disordered by a 60° rotation exist along a 6-fold axis down the [001] direction. A superconducting transition at 0.72 K is clearly indicated by resistivity measurements. © 2002 Elsevier Science.