Beiträge zur Untersuchung anorganischer nichtstöchiometrischer Verbindungen. XXX. Elektronenmikroskopische Untersuchung in Hochauflösung an metastabilen Niob-Wolfram-Oxiden Vergleich mit der rechnerischen Simultation

Contributions to the Investigation of Inorganic Non-stoichiometric Compounds. XXX. High Resolution Electron Microscopy Investigation of Metastable Niobium Tungsten Oxides. Comparison with Computer Simulated Images . Starting with solid solution series (Nb, W)O_x, where WO₃ + NbO₂ was substituted for Nb₂O₅, a gentle oxidation leads from the original block sizes of [3 × 4], [4 × 4], [4 × 5] or [5 × 5] octahedra to a doubling of blocks in the new ternary oxides, e. g. 2 × [5 × 5] → [5 × 10]. As HRTEM of the oxidation products revealed, these new larger blocks are connected in a special way including so-called “L-type-tunnels”. Using a LaB₆-cathode with our electron microscope, we now for the first time can directly see the positions of these tunnels.