Darstellung und Kristallstruktur von BaMnSb2, SrMnBi2 und BaMnBi2 / Preparation and Crystal Structure of BaMnSb2, SrMnBi2 and BaMnBi2

BaMnSb2, SrMnBi2 and BaMnBi2 have been prepared and structurally characterized. The new compounds are isotypic and crystallize tetragonal in the SrZnBi2 structure with the following constants: BaMnSb2: a = 4.53 ± 0.01 Å, c = 24.34 ± 0.03 Å, c/a = 5.37. SrMnBi2: a = 4.58 ± 0.01 Å, c = 23.13 ± 0.03 Å, c/a = 5.05. BaMnBi2: a = 4.63 ± 0.02 Å, c = 24.22 ± 0.05 Å, c/a = 5.23. The transition metal atoms form together with the semimetal atoms sheets of tetragonal pyramids separated by double layers of alkali earth atoms. In these double layers there are inserted Bi/Sb-square nets.