Matter at extremes

The scientific programmes of the Matter at Extremes Group cover all classical domains of natural sciences with a significant impact in applied fields such as Earth, environmental and planetary science, catalysis, soft matter, material synthesis, and nanoscience. The introduction to the group's chapter in the annual ESRF Highlights gives an overview of some recent accomplishments.

High pressure studies are possible on all the beamlines in the group, but each beamline is optimised for a specific X-ray technique.  Time resolution is becoming increasingly important, and static high pressure studies are now being complemented by a few dynamic compression experiments. The pressure and temperature ranges covered by the different techniques vary, depending not only on the X-ray beam characteristics but also on the sample environment at the beamline. Static pressures beyond 200 GPa and temperatures from 5 K to 5000 K are available on some of the beamlines. High pressure structural studies employ monochromatic (angle-dispersive) diffraction using diamond anvil cells (DAC) (ID27 and ID15B). The DAC techniques are complemented by the Paris-Edinburgh press (ID27 and BM23), and the large volume press (ID06). Time-resolved structural studies of phase transformations down to the microsecond scale will soon be feasible at ID27. 

Structural dynamics such as collective excitations in disordered materials and phonons in crystalline materials are investigated by nuclear inelastic scattering (ID18). Furthermore, nuclear resonance scattering allows the study of diffusion and rotational motions directly in the time domain, as well as electronic and magnetic properties and their dynamics in the nanosecond to microsecond time regime.

Local structure, electronic and magnetic properties  and their time evolution down to the ns timescale are studied utilising X-ray absorption spectroscopy and X-ray magnetic circular dichroism (ID24 and BM23). Extreme states of matter that can be achieved only during short time intervals (< ns) can also be probed by single bunch acquisition.