# Interpreting HRTEM Images

| Here is a HTEM picture of grain boundaries in BaTiO3, one of the most important electroceramic materials. Its lattice is of the Perovskite type and looks like this:
|  | The Ti atom is in the center and the O atoms on the face centers positions. The lattice is not exactly cubic but slightly elongated. A HRTEM image from Prof. Urbans group (Res. Center Jülich) shows many grain boundaries:
|  | The link provides a large-size copy. Can you figure out the structure of the boundaries? Are there any dislocations present? This is not so much an exercise but a demonstration that even images with atomic resolution do not solve all problems.

With frame

Ionic Crystals

8.3.1 Steps in Interfaces

Grain Boundaries in BaTiO3 - Large Size

© H. Föll (Defects - Script)