The reorganisation of the Experiments Division during 2009 saw the creation of the new Structure of Materials group, combining the beamlines dedicated to surface and interfacial science – ID01, ID03 and ID32 – with those for structural studies of bulk materials and buried interfaces using predominantly hard-energy photons to penetrate through dense absorbing samples and sample environments, ID11, ID15 and ID31. Understanding bulk, surface and interfacial characteristics is of crucial importance in designing and optimising the performance of modern materials and systems composed from them. Furthermore, this provides a rich domain for the investigation of fundamental physical and chemical properties of natural and synthetic substances. Many user groups and beamlines at ESRF carry out research important to the broader materials area, especially our colleagues in the CRG beamlines. Hence this chapter has evolved into a substantial compilation, with nineteen highlight articles -the tip of the iceberg- drawn from some fifteen beamlines. They cover a variety of themes.

One theme is the phenomenon of self organisation or self assembly: the way in which surfaces or molecules adsorbed on surfaces organise themselves spontaneously to optimise their mutual interactions. Surface roughness, molecular coverage and aggregation can hold profound influence over the optical, magnetic and electronic properties, and can affect resistance to corrosion, etc. Very small objects such as quantum dots and nano-islands grown on substrates have modified properties because of the confinement of the electrons within these structures, further modified by the effects of strain or chemical composition gradients, allowing, potentially, the possibility to tune such properties for specific applications.

In situ studies, in which a system is monitored while undergoing chemical or physical evolution, require rapid data acquisition with a time resolution appropriate for the process under investigation. Detailed information about the underlying mechanisms can be extracted, from which more effective and efficient processes can be envisaged. Two of the examples presented here are of relevance to a cleaner environment and energy research, with investigation of the oxidation of carbon monoxide over a precious metal catalyst, used to reduce the toxicity of the exhaust gas from a car, and the investigation of the distribution of the crucial water component in the proton exchange membrane in a working hydrogen fuel cell.

Finally, there is atomic structural characterisation of a range of bulk materials, such as metallic glasses, or investigation of the evolution of structure at low temperatures or when applying pressure. These systems often have electronic, magnetic, or superconducting properties and the behaviour under changing conditions can reveal subtle details of the underlying electron, spin and orbital-ordering interactions.

These studies exploit the properties of ESRF’s synchrotron X-rays, i.e. great intensity, stringent collimation and an ability to focus the beam to sub-micrometre dimensions, wavelength tunability (with access to very hard photon energies), coherence, and the time structure of the source. With the upgrade underway, plans for future developments to the group’s capabilities include the two beamline projects UPBL01 and UPBL02, evolutions of ID01 and ID15, respectively. Instrumental progress during the last year includes the installation of an in-vacuum, white-beam, refractive-lens transfocator on ID11, allowing great flexibility for focussing or condensing the beam with impressive increases in photon density at the sample. Such is the success of this device that ID15 will also be installing one in early 2010. ID32 has commissioned a new setup for hard X-ray photoelectron spectroscopy (HAXPES) and X-ray standing wave measurements. The new spectrometer allows up to 15 keV electron kinetic energies and 50 meV resolution and is also equipped with a UHV preparation chamber, cryostat (30 K) and a load lock. The old XSW chamber and analyser have been removed from the experiments hutch. Finally, Till Metzger has left ID01 after nearly ten years as scientist in charge of the beamline where (among many other achievements) he built up the current programme on coherent diffraction imaging. We send him our very best wishes for his sabbatical leave and future retirement.

A. Fitch