Dresden 2003 – wissenschaftliches Programm

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SYEC: Materials under extreme conditions

SYEC 1: Extreme Conditions I

SYEC 1.2: Hauptvortrag

Mittwoch, 26. März 2003, 14:30–15:00, HSZ/01

High pressure phonon studies by inelastic x-ray scattering — •Michael Krisch — European Synchrotron Radiation Facility, BP 220, F-38043 Grenoble Cedex, France

Starting from the pioneering work in the 1980’s, and profiting from the availability of dedicated synchrotron radiation sources and performing x-ray optics, inelastic x-ray scattering (IXS) with meV energy resolution is nowadays a powerful spectroscopic tool in the study of collective atom dynamics in condensed matter. IXS finds applications in research fields ranging from biology to materials science, and studies under extreme conditions such as high temperature and/or high pressure play an increasingly important role. IXS complements the traditional coherent inelastic neutron scattering (INS) techniques in an energy-momentum transfer region which is not accessible with neutrons due to kinematic limitations, and in the study of very small samples. In recent years high pressure studies were performed on liquid, polycrystalline and single crystalline systems, utilising both large volume and diamond anvil cells (DAC’s). In particular DAC’s allow to obtain pressures above 100 GPa, therefore sensibly increasing the pressure range currently obtained by high-pressure INS techniques. The present status shall be illustrated by presenting results on polycrystalline iron [1], water [2], and single crystalline cobalt.

[1] G. Fiquet, J. Badro, F.Guyot, H. Requardt, and M. Krisch, Science, 291, 468 (2001).

[2] M. Krisch et al., Phys. Rev. Lett. 89, 125502 (2002).