CRYSTALLOGRAPHY UNDER EXTREME
CONDITIONS
Heinz Schulz
Institut für Kristallographie, Universität
München, Theresienstr. 41, D-80333 Munich, Germany,
E-mail: Heinz.Schulz@lrz.uni-muenchen.de
Keyword: high pressure, high temperature,
microcrystal diffraction, time resolved diffraction
Experiments in crystallography depend on the efficiency of
facilities and equipments or on newly developed tools. Such
devices may open bounderies, so that crystallography can enter
new fields for studying properties of crystaline material. Some
examples for such modern developments will be treated in this
talk. These are:
- High pressure experiments with diamond anvil cells, which
allow experiments up to several hundred GPa, this means
at pressures higher than in center of the earth.
- High temperature experiments above 2000K.
- Combination of high pressure and high temperature
experiments, by which phase boundaries can be studied,
e.g. those which play an important role in the interior
of the earth and of the planets.
- Microcrystal diffraction with single crystals of volumes
between 0.1 to 1 m3. Such crystals can
now be handled and used for single crystal diffraction
experiments. Their diffracted intensities are free of
systematic errors. In such a way the very efficients
single crystal methods can be applied to crystaline
material, which up to now could only be investigated in
the form of polycrystaline samples.
- Time resolved diffraction experiments, which can be
carried out already at nanoseconds.
The equipments neccessary for such experiments and results
obtained are reviewed with emphasis on high pressure experiments.