Recent developments in the structural science of materials

Abstract

The articles published recently in IUCrJ illustrate the rapid advances that are being made in this increasingly diverse field. There are very extensive and exciting developments in experimental technique, accompanied by progress in data processing and analysis and a growing integration with computational simulation. The field explores a wide range of classes of material including, of course nano-structured materials; while a multidisciplinary approach-long a major feature of the structural materials science-is evident in all the recently published studies. Technical innovation is central to the field. An important and highly topical example is the study of Dejoie et al. (2015) demonstrating the potential of 'Serial Snapshot Crystallography in Materials Science' This pioneering work used synchrotron radiation to simulate the type of brilliant ultra-fast X-ray pulses that will be available from X-ray free electron lasers (XFELs) which are being developed around the world. Using Laue techniques, which will be available on the SwissFEL source, they were able for several inorganic materials to collect data which could be at least partially analysed from a single shot of a 10-50 femtosecond pulse. As they comment, the success of this work offers 'tantalizing possibilities for time-resolved studies'. And indeed with the increasing availability of XFEL sources in the coming years a new area of structural materials science will be opened up. A perennial problem in the structural science of solids is the treatment of disordered systems, which embrace some of the most widely studied and significant materials, including ceramics (e.g. the very widely studied stabilized zirconia system) and zeolite catalysts. Analysis of diffuse scattering plays a key role here and the current state-of-theart is reviewed by Welberry & Goossens (2014), who illustrate both the quality of the data which are available with current sources and instrumentation, an illustration of which is given in Fig. 1 for the case of benzil collected on the 11-ID-B beamline of the Advanced Photon Source (APS). In conjunction with modelling, using Monte-Carlo and ab-initio techniques, data of this quality will offer new possibilities in developing detailed models of disordered materials. Technique development is also at the forefront of several other contributions, including the work of Rafaja et al. (2014) who exploited the high sensitivity of X-ray diffraction to macroscopic and microscopic lattice deformations in their study of metastable thin films; while Tria et al. (2015) report the development of ensemble modelling techniques in the analysis of X-ray solution scattering data from flexible macromolecules. Developments in data analysis and structure solution are highlighted in the feature article of Rius (2014) which surveys the current status of Patterson-function direct methods (PFDM); while more fundamental theoretical aspects are explored in the article of Marzouki et al. (2014) concerning the analysis of structural continuity in twinned crystals. Other ...