Superconducting non-centrosymmetric boride Mg₁₀Ir₁₉B₁₆: crystal structure and chemical bonding

Chem. Met. Alloys 7 (2014) 74-84

https://doi.org/10.30970/cma7.0275

Anastasia M. ALEKSEEVA, Andreas LEITHE-JASPER, Yuri PROTS, Walter SCHNELLE, Alim ORMECI, Evgeny V. ANTIPOV, Yuri GRIN

A single-phase sample of Mg₁₀Ir₁₉B₁₆ was prepared from the elements by high-temperature treatment in sealed Ta containers. The crystal structure of Mg₁₀Ir₁₉B₁₆ (space group I-43m, a = 10.5657(2) Å, Z = 2) was solved and refined using X-ray single crystal diffraction data. The chemical composition was confirmed by WDXS analysis. The absence of any significant homogeneity range was proven via lattice parameter determinations for samples of different nominal compositions. Electronic structure calculations and chemical bonding analysis by the ELI/ED approach revealed that the basis of the Mg₁₀Ir₁₉B₁₆ structure is formed by a 3D anionic framework of covalent polar B–Ir bonds. Mainly ionic interactions were found between the Mg cations and the anionic framework, supported by additional dative Ir-Mg bonding.

QTAIM atomic basins and effective charges in Mg₁₀Ir₁₉B₁₆.

Keywords

Superconducting boride / Crystal structure / Chemical bonding