Electron Diffraction and Electron Microscopy

Sven Hovmöller	Structure Determination Using Electron Diffraction	A
W. Neumann, R. Schneider, H. Kirmse, I. Hähnert	Transmission Electron Microscopy of Quantum Structures	A
X.Z. Li, V. Hansen, K. Stiller, G. Waterloo, R. Wallenberg, J. Gjonnes	An Electron Crystallography and Atom Probe Investigation of Zones and Precipitate Phases in Industrial Al-Zn-Mg Alloys	A
J. Gjonnes, V. Hansen	Symmetry in real and reciprocal space in dynamical electron diffraction: a Bloch wave description including higher Laue zones	A
G.N. Kryukova, S.V. Tsybulya	Systematic Study of the Microstructure of Different Oxide Catalysts Using X-Ray Powder Diffraction and High Pressure Electron Microscopy	A

In this symposium it was clearly demonstrated that electron crystallography is maturing as a method for structure determination. Sven Hovmöller showed that it is possible to solve unknown crystal structures either from high resolution (2A) electron microscopy (EM) images or even from electron diffraction (ED) patterns using direct methods. The size of the crystal can be as small as 10 - 1000 unit cells, i.e. only a few nanometers in each direction. There are instruments and software available for accurate quantification of both EM and ED data and this allows structure refinements to an accuracy of about 0.01 A in atomic positions of inorganic crystals. Wolfgang Neumann and the Oslo group (Gjonnes, Hansen and Li) demonstrated the great opportunities of electrons for characterising new advanced materials, including quantum wires and quantum dots and clusters and precipitates in alloys. Kryukova from Novosibirsk presented impressive examples of how superstructures can be characterized in detail by electrons, with examples of different metal oxides used for catalysis.