High resolution electron microscopy studies of Ba4Nb14O23

The new compound, Ba₄Nb₁₄O₂₃, has been prepared by heating mixtures of Ba₅Nb₄O₁₅, Nb₂O₅ and Nb at 1 450°C under Ar. Ba₄Nb₁₄O₂₃ has been studied by means of high resolution electron microscopy and X-ray powder diffraction techniques. It has a C-centered orthorhombic unit cell with a=20.782(4), b=12.448(3), c=4.148(1) Å and Z=2. The structure of Ba₄Nb₁₄O₂₃ can be considered as being an intergrowth between BaNbO₃ and NbO. Characteristic building units are triple chains of corner sharing Nb₆ octahedra which are connected via columns of the perovskite type structure to a three dimensional network.