One of the principal uses of synchrotron radiation is the investigation of the microscopic structure of materials, extending from macromolecules and pharmaceutically active compounds through to surfaces and nano-structures that make up devices used in high-technology applications. Structural information can be obtained over wide range of length scales, from detail of interactions at the atomic level through to the complex structures of devices and composites, and the grain structure of metals and alloys. Such information is essential to understand the properties and performance of a system. Many of the studies performed using ESRF instruments are of direct relevance to modern materials systems and can provide information fundamental for improvements and further developments.

The highlights from ESRF and CRG beamlines selected for 2013 illustrate a number of areas where the use of the synchrotron and advanced X-ray detectors is essential. The production of brilliant beams focused to the nm scale coupled with the exploitation of coherence allow the characterisation of defects, strain and the microstructure that affect the properties and performance of nanoscale semiconductor structures grown in the fabrication of electronic devices. Quantitative information can be derived, such as the number of dislocations and the size of a defected volume, which can then be correlated with the fabrication process and the resulting performance.

The high intensity of synchrotron radiation allows systems that are evolving with time to be investigated, such as the structure and chemical state of an industrial catalyst in a realistic operating environment, or the setting of cement - one of the most ubiquitous materials in the modern world - and the influence of additives that help improve the handling, flow, and final strength of the product. In the latter study, the setting was followed on the sub-second time scale, with the cement suspended in an acoustic levitator to ensure that the walls of a container did not influence the chemical reactions under investigation.

Novel materials continue to be devised in chemistry laboratories and synchrotron radiation plays a vital role in determining their structures. New systems recently studied at ESRF include zinc oxide, a wide band-gap semiconductor, with incorporated amino acids that influence the crystal lattice strain and the band gap. Microporous materials such as zeolites and metal-organic framework materials (MOFs) are of current interest as they can be used in a wide range of applications, including catalysis, and are potentially useful for storing gasses such as hydrogen or for sequestration of carbon dioxide. The crystal structures and properties can be understood using synchrotron studies and this information can be fed back for the design and creation of yet more novel materials with desired properties.

The past year has been especially busy for the Structure of Materials Group with final detailed planning for the construction of two Upgrade Programme beamlines and major modifications to two more of the group’s beamlines, in addition to the ongoing development and refinement of experimental capabilities in general. Both ID01 and ID31 closed down in December 2013. ID01 will be reconstructed as upgrade beamline project UPBL1, «Diffraction imaging for nanoanalysis», a long beamline extending into the new experimental hall, with nanofocus capabilities, at energies up to 45 keV, for coherent diffraction nano-imaging and anomalous scattering. Construction of upgrade beamline project UPBL2, «High energy beamline for buried interface structures and materials processing», starts at ID31 in January 2014, again a long beamline, with nanofocus capabilities extending up to photon energies of 150 keV. This beamline represents a major enhancement of current capabilities at ID15.

The high resolution powder diffraction beamline is moving from ID31 to ID22, where it will benefit from reduced horizontal divergence on a high-β sector of the storage ring and an increase in its operational range to 80 keV. In late 2014, a large 2d medical imaging detector will be acquired to complement studies made using the high-resolution scanning detector system. The final beamline to be rebuilt in the current phase 1 of the ESRF Upgrade Programme is ID15, which will be redeveloped, incorporating on the B branch high pressure diffraction (relocation of ID09A), and on the A branch continuation of the high energy facilities for materials characterisation and materials chemistry, including use of the white beam as needed.

A. Fitch