Synthesis and crystal structure of the new Mg₈Rh₄BD_3.5 deuteride

Chem. Met. Alloys 10 (2017) 106-112

https://doi.org/10.30970/cma10.0364

I.Yu. Zavaliy, Yu.V. Verbovytskyy, V. Paul-Boncour, R. Denys, V. Berezovets, A. Riabov

The crystal structure of the Mg₈Rh₄BD_3.5 deuteride has been investigated by both X-ray and neutron powder diffraction at 300 and 10 K. Deuterium absorption by Mg₈Rh₄B proceeds through isotropic expansion of the unit cell volume by 4.1% in the same cubic structure (Fd-3m) as the parent compound. The deuterium atoms mostly occupy tetrahedral 32e sites with Mg₃Rh surrounding (93.5% of the total D content), however, a small occupancy of octahedral 16d sites (Mg₆) was also observed.

Projection of the structure of Mg₈Rh₄BD_3+x onto the XY plane.

Keywords

Metal hydride / Magnesium compounds / Crystal structure / X-ray and neutron powder diffraction