The invention of the diamond anvil cell has had an enormous impact on
high pressure research, both in terms of the range of static pressures
that can be reached and in variety of techniques that can be employed
to study the behavior of the matter at high pressure.
The pressure that can be generated by modern diamond anvil cell are
higher than those at earth's center. Many materials can be compressed
to less than half their volumes at atmospheric pressure. Such an
enormous compression ca affect many basic properties of a crystal such
as crystalline structure, lattice parameters and electronic structure
including pressure induced insulator to metal transitions, Using the
diamond anvil cell facilitates the direct comparison of experiments
and first principle bonding calculations and provides the basis for
improving the approximations used in some fundamental approaches to
bonding. At present the diamond anvil cell clearly offers the
opportunity to perform a variety of rather sophisticated measurements
to 50 GPa pressures, and in some of these experiments pressure can be
extended to megabar region.
After a brief description of the different types of DAC that are
currently in use, the techniques employed in conjunction with DAC in
modern high pressure research will be presented. These include low and
high temperature investigations, X-ray diffractometry, spectroscopy
and other measurements. Selected results illustrating the potential of
DAC including recent achievements in megabar pressure region will be
given and discussed.