The crystal structure of aluminum doped β-rhombohedral boron

Titelangaben

Bykova, Elena ; Parakhonskiy, Gleb ; Dubrovinskaia, Natalia ; Chernyshov, Dmitry ; Dubrovinsky, Leonid:
The crystal structure of aluminum doped β-rhombohedral boron.
In: Journal of Solid State Chemistry. Bd. 194 (2012) . - S. 188-193.
ISSN 0022-4596
DOI: https://doi.org/10.1016/j.jssc.2012.05.011

Volltext

Link zum Volltext (externe URL):

Abstract

A crystal structure of aluminum doped β-rhombohedral boron was studied by single-crystal X-ray diffraction at 80 K. The crystals were synthesized using high-pressure high temperature technique at 3 {GPa} and 2100 K. The structure is based on three-dimensional framework made of {B12} icosahedra with voids occupied by the B28–B–B28 units, it has the R-3m space group with a=10.9014(3), c=23.7225(7) Å lattice dimensions in hexagonal setting. Aluminum atoms are located in {A1} and D special positions of the β-B structure with occupancies of 82.7(6) and 11.3(4), respectively. Additional boron atoms are located near the D-site. Their possible distribution is discussed. Finally we have found two appropriate structural models whose refinement suggests two possible chemical compositions, AlB44.8(5) and AlB37.8(5), which are in a good agreement with the chemical analysis data obtained from EDX. The crystal structure of AlB44.8(5) is described in detail.