The Sodium Antimony Telluridogermanate(III) Na₉Sb[Ge₂Te₆]₂

Abstract

Systematic studies in the quaternary system Na/Ge/Sb/Te yielded the new compound Na 9 Sb[Ge 2 Te 6 ] 2 . Its crystal structure is isotypic to Na 9 Sb[Ge 2 Se 6 ] 2 (space group C2/c with a = 9.541(2), b = 26.253 (7), c = 7.5820(18) Å and β = 122.233(15)°, Z = 2). The structure is characterized by Ge-Ge dumbbells that are octahedrally coordinated by Te, forming ethane-like [Ge 2 Te 6 ] 6anions. Cation sites are