Looking back at the year 2010 gives us an opportunity to present a selection of exciting results arising from work at the Electronic Structure and Magnetism group beamlines. We can reflect on how these results offer promise for the future. Similarly, it is timely to look forward to improvements to the experimental facilities, their upgrade began in 2010, and will undoubtedly provide many more research Highlights.  

The pursuit of basic research and understanding its place in creating technologies of the future are essential ingredients in the articles selected for this year’s Highlights. The article by Mannini et al. on molecular magnets presents as a goal of these studies the creation of devices at the molecular level for magnetic, electronic, photonics and sensor applications. This is also reflected in the article by Arrio et al., which presents results on a photomagnetic molecular magnet. The switching of such materials using light, temperature, electrical or magnetic stimuli represents one of the most interesting current directions in the search for scaled down devices.

The quest for room temperature dilute magnetic semiconductors, Edmonds et al., is another example of basic research contributing to the materials of the future.  This could, in particular, have an impact on the future magnetic recording and storage devices.

The interest in interfacial studies has its roots also in the possibility of tailoring new functionality. Many new phenomena, of potential applied use, are also being observed at interfaces. Conducting layers produced at the interface between insulators is one dramatic example [1]. In the article by Garcia-Barriocanal et al., the authors show how X-ray spectroscopy can highlight the subtle electronic structure changes that occur at interfaces and help to understand and control the properties at such interfaces.

Other materials of resurgent interest are the multiferroics. The article by Fabrizi et al. shows how X-ray magnetic scattering can help in understanding their domain structure, which is important for their use in real devices of the future.

Much of the research also addresses current problems and there are many examples in this year’s Highlights.  Understanding the chemistry of actinides in our environment is of great importance to the nuclear industry (Galbis et al.) and appreciating how materials remove heavy metals during the gasification of coal is of clear environmental interest.

Turning to the evolution of our research facilities, the past year has seen the closure of BM29 and ID24 for a major refurbishment as part of the ESRF Upgrade Programme. The standard EXAFS part of the new ID24/BM23 complex has been rebuilt and now enters the commissioning phase, with user operation recommencing in the first half of 2011.

BM23 is optimised for standard EXAFS in transmission geometry in a large energy range (4-75 keV) and in addition acts as a user/in-house EXAFS/XRD rapid access facility for sample characterisation. It complements the solid platform of highly specialised XAS/XES beamlines, allowing the ESRF to offer a complete spectrum of X-ray absorption spectroscopy techniques, an offer unequalled in Europe. Examples of Highlights from BM29 can be seen in the articles by D’Angelo et al. and Poulston et al. .

Commissioning the new ID24 dispersive EXAFS stations will start in mid-2011. The facility will provide optimised branches for small and large spot activities. The new complex will focus on investigating solid and molten matter at extreme conditions of pressure, temperature and magnetic fields using in situ static and dynamic XAS. We will provide the users community with the first “in situ” laser heating facility optimised for X-ray absorption spectroscopy.  This facility will address fundamental questions such as understanding the local structure of molten metals at high pressure, and the kinetics of chemical reactions at extreme conditions.  Applications will cover hot topics in geophysics such as the partitioning of Fe in the upper/lower mantle (see Highlight article Andrault et al.), to the synthesis and characterisation of new materials for extreme environments, such as those envisaged for fusion reactors.

From the perspective of the chemical sciences, the new beamlines offer much. In particular, the small spot branch of ID24 will offer new opportunities for tackling the time-resolved study of homogeneous chemical reactions and aspects of solid-state chemistry. The large spot branch will be equipped with an infrared spectrometer equipped with a novel optical system providing a unique hub for the continuing exploitation of dispersive EXAFS/infrared measurements in the fields of catalysis and related disciplines. Most notably a combination of step scan infrared and ultrafast dispersive EXAFS measurements together with photo-excitation or laser heating will offer a unique possibility for studying fundamental aspects of thermally or photon driven catalysis and solid state chemistry on the milliseconds to nanoseconds timescales. An example of highlight work in this area can be found in the article by Newton et al. in the chapter on Structure of materials.

N.B. Brookes

 

References

[1] See for example: H. Chen, A.M. Kolpak and S. Ismail-Beigi, Advanced Materials 22, 2881 (2010) and references therein.