Trial model for the tilting scheme in AgNbO3 derived by electron diffraction and imaging

Transmission electron diffraction and imaging are applied to derive a proposal for the tilt scheme of the perovskite based structure of silver niobate (AgNbO3). Electron diffraction data enable a reduction of the possible spacegroups down to two, each compatible with a number of tilt schemes for the octahedra in the perovskite like structure. With the aid of high-resolution imaging a single tilt scheme can be proposed. The HREM image interpretation is substantiated by image simulation based on the real space patching method. (author)