Synthesis and crystal structure of the new Mg8Rh4BD3.5 deuteride

 

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

 

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

 

The crystal structure of the Mg8Rh4BD3.5 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 Mg8Rh4BD3+x onto the XY plane.

 

Keywords

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