This chapter gives a number of examples where the structure, reactivity and interactions in materials have been investigated through the use of synchrotron radiation at ESRF. The study of materials covers a wide range of fundamental and applied science and is one of the primary areas of research at the ESRF. The measurements can lead to a real understanding of why systems behave the way they do, and can result in the longer term to the design and production of new materials with enhanced properties and to the optimisation of the behaviour and longevity of existing systems. The ESRF’s powerful X-ray beams can be tailored to probe structures on different scales, revealing the ordering of atoms in crystalline substances or the microstructural arrangement of crystallites in bulk materials, as well as providing detailed structural information at surfaces and interfaces that control so many properties like catalytic activity, corrosion resistance, and are exploited in the design and production of advanced microstructures and electronic components. The great intensity of the X-ray beams coupled with detectors that can operate at high speed allow studies of systems as they undergo change, thus permitting experiments that follow in situ the evolution of samples under conditions that may resemble those approaching realistic operating conditions.

One such in situ study developed a novel method for observing the formation of clathrate hydrates, which are crystalline solids in which small molecules (particularly gas molecules) are trapped inside cages composed of hydrogen-bonded water molecules. Clathrates can form spontaneously and block oil and gas pipelines. Large quantities of methane clathrates reside in the cold high-pressure environments on ocean floors, and there are ideas that clathrates might be exploited as a fuel source, or even used to sequester carbon dioxide from the atmosphere. In the study, droplets were suspended free of contact in an acoustic levitator and high-speed photography and X-ray scattering were used to follow the process of crystallisation, allowing insight into the mechanism of clathrate formation. In another in situ study, electrochemical etching of gold was followed in a special cell on the millisecond time scale by grazing-incidence X-ray scattering at rates comparable to those in microchip metallisation processes. For etching, the measurements gave clear evidence for a layer-by-layer dissolution mechanism. The opposite process, that of electrochemical deposition which is also of great technological importance, can also be followed by the same approach.

On the instrumental front in the structure of materials group of beamlines, plans for UPBL1 (upgrade of ID01) and UPBL2 (upgrade of ID15 to be built at ID31), and the transfer and refurbishment of ID31 continue to develop. Both ID01 and ID11 installed new high precision diffractometers during the year and ID03 will install a new diffractometer next year. On the downside, it has been decided to close ID32, devoted to hard X-ray photoelectron spectroscopy (HAXPES), X-ray standing waves (XSW), electrochemistry and general surface science, to make way for UPBL7. This is a consequence of the reduction in ESRF’s operating budget, and the need to relocate UPBL7 in a different sector of the ring, and represents a significant loss to the ESRF’s scientific capacity. No further experiments have been accepted for the beamline, which will complete its outstanding user programme. A workshop attached to the 2012 users meeting will explore the future needs and the conceptual design for a future renewed HAXPES/XSW beamline at ESRF.

A. Fitch