New barium niobium sulfides II. Preparation of BaNb2.85S6.23 and BaNb5.33S11.0

Abstract Unknown barium niobium sulfides have been prepared by controlling the partial pressure of sulfur. The chemical compositions of the sulfides are BaNb 2.85 S 6.23 and BaNb 5.33 S 11.0 . The X-ray powder diffraction patterns of the sulfides were indexable in a hexagonal setting with the reflection condition of − h + k + l = 3 n . The lattice parameters are a = 0.33341(2) nm and c = 6.3714(4) nm for BaNb 2.85 S 6.23 , and a = 0.33339(2) nm and c = 10.0450(7) nm for BaNb 5.85 S 11.0 . Electron diffraction patterns revealed a superstructure of 3 a × 3 a . The conditions to prepare the single pure phases were examined.