F169 (2002). Stepped superstructure in Bi8W2Nb2O23.
Top: HRTEM image of Bi8W2Nb2O23, viewed down the  zone axis of a Bi2WO6-like subcell. The insets show a corresponding SAED pattern and a simulated image from a proposed model with 8 nm specimen thickness and 60 nm lens defocus. Bottom: Stepped superstructure in a zigzag arrangement. [W. Z. Zhou, J. Solid State Chem. 163, 479–483 (2002)].