Materials Science

Introduction

Materials science research continues to play a major role at the ESRF and spans a wide range of applications. The present trend is that, with increased brilliance and the ability to produce sub-micrometre focussing of the X-ray beam, new experiments are becoming accessible to the beamlines. The complexity of the structures studied are increasing, the sample sizes and measuring gauges are decreasing, the accessible range of pressures and temperatures are increasing and the available time-resolution is in the picosecond regime. Since materials science is so broad, other chapters also cover many applications in this highlight presentation.

This chapter is structured into four different sections:

• Materials science and solid-state chemistry at work
• High-pressure diffraction
• Subnanosecond-resolved diffraction
• Stress and strain studies at the ESRF

In the solid-state chemistry part we highlight the structure determination of very large supramolecular assemblies by single crystal determination from tiny and rather difficult crystals. The powder diffraction method has been extended by the implementation of a new insertion device enabling the ab initio solution of previously inaccessible complex structures. Studies of nanostructure evolution and spin / magnetic phase transitions are other areas illustrated. The high-pressure diffraction field is expanding and a new high-brilliance high-pressure beamline is being constructed. The science spans a wide range from studies of iron-silicon alloys and spinels at extreme conditions to structural properties of diamond at high pressures and pressure modulated structures of antimony. The sub nanosecond-resolved diffraction has reached maturity as illustrated by a picosecond "movie" of myoglobin in action and structural kinetics studies of photochemical reactions in solution. The stress and strain studies are geared towards novel studies of residual stress in industrially important compounds. Notable studies are the combined study of metal matrix interfaces by diffraction and imaging as well as depth-resolved studies of friction stir welding. The FaME38 project is a collaboration between seven British research institutions, the ILL and the ESRF. Its aim is to improve and streamline engineering experiments and so provides new opportunities for engineers at the two facilities.

Å. Kvick