Electron diffraction reveals the crystal structure and symmetry of the sample material. In the selective area diffraction (SAD) mode the lateral resolution is limited by the size of the selection-aperture going down to ~ 250 nm. For higher lateral resolution convergent beam electron diffraction (CBED) is also possible reaching a resolution of a few nanometers.

For a characterization of the 3-d structure it is necessary to acquire a tomographic tilt series at first, i.e. image the sample at different angles of projection. Typically a such a tilt series is acquired with steps of one degree from +80° to -80° angle between sample and incoming electron beam (see figure 5). At the ICAN a special tomography needle holder is also available allowing for a 360° rotation reducing artefacts (missing wedge) in the reconstruction. An exemplary tilt series of core-shell nano-particles is seen in figure 6. Different methods like weighted back projection or simultaneous iterative reconstruction are then used to create a three-dimensional model of the sample structure figure 7).

After interaction with the shell electrons, the primary electrons lost a specific amount of energy themselves. This loss of energy is again element specific and depends on the energy difference of the excitation. Using an electromagnetic prism the energy loss of the primary electrons may be analyzed revealing not only elemental composition but also chemical bonding in the nanometer regime. In figure 10 the Ti-L23 edge is shown. The number and separation of the four peaks allows the identification of the number of oxygen atoms the titanium is bond to.