Zur Kenntnis eines Barium-Lanthanoid-Aluminat-Zinkats: BaLuAlZn₃O₇ mit einem Anhang zu Ba₂Er₂Zn₈O₁₃/On a Barium Rare Earth Aluminate Zincate: BaLuAlZn₃O₇ with a Note on Ba₂Er₂Zn₈O₁₃

Abstract

Abstract Reactions of BaCO 3 , ZnO, Lu 2 O 3 and Al 2 O 3 mixtures at temperatures up to 1500 °C led to small and colourless rods of BaLuAlZn 3 O 7 . The new compound crystallizes with hexagonal symmetry, space group C 6v 4 -P6 3 mc, a = 6.273, c =10.161 Å, Z = 2. In spite of small differences in the oxygen content BaLuAlZn 3 O 7 is isotypic to Ba 2 Ln 2 Zn 8 O 13 . The crystal structure shows Zn 2+ with tetrahedral, Lu 3+ with octahedral and Ba 2+ with anticuboctahedral coordination by O 2- . It has been shown that parts of the [Zn 3 AlO 7 ] 5- network are fragments of the ZnO structure. In consequence one oxygen atom is fourfold coordinated by zinc/aluminium. The space group of Ba 2 Ln 2 Zn 8 O 13 must be corrected to C 6v 4 -P6 3 mc.