Structures of three new metastable ruthenium oxides have been determined as a result of a collaborative project between three academic institutions and sustainable technology company Johnson Matthey. Ruthenium oxides are used in electro-catalysis for water oxidation and reduction, in heterogeneous catalysis, and are also of interest for their electric and magnetic properties. The majority of transition metal oxides are prepared at high temperatures, resulting in the formation of only the most stable compounds. The potential for many metastable oxides exists, such as compounds with unusual oxidation states that are inaccessible using conventional synthesis conditions.Read more...
The UK metal casting industry employs ~30,000 people, contributes ~£2.5 billion per year to the economy, and plays a key role in manufacturing across the automotive, aerospace, defence, and energy sectors. However, there is strong global competition in metal casting which drives manufacturers to seek ways to minimise casting defects such as pores and cracks whilst reducing cost. This research carried out by a team of scientists from the Imperial College London, University of Manchester, and Diamond Light Source focuses on understanding the deformation behaviour of solidifying metals and the origin of casting defects so that physically-based models of defect formation can be developed.Read more...
Metal-organic frameworks (MOFs) are versatile materials with many applications in areas such as catalysis and hydrogen storage. Recently it was found that certain MOFs contain defects, which could lead to new functionality if the locations of the defects are better understood so that they can be exploited. Correlated disorder and defects are abundant in exotic materials such as ferroelectrics and superconductors, where the defects are not randomly distributed but interact such that their positions are dependent on other defects. Previous research has indicated that one of the canonical MOFs, UiO-66(Hf), contains ligand-absence defects.Read more...
Long Duration Experimental Facility
Facility On the Powder Diffraction beamline (I11), the Long Duration Experiment (LDE) instrument has opened operation for users. It is situated in a second experimental hutch (EH2) right behind I11’s powder diffraction area in EH1. This new facility is the world’s first synchrotron long duration experimental instrument. It will open up completely new opportunities for the study of changes in the properties and behaviour of materials that take place over an extended period of time. Samples are set up within custom built sample environments and measured each week to study in situ long term behaviour as it occurs in natural states or processing conditions. With several environmental cells readily loaded, the facility is capable of running different experiments simultaneously. Consequently, LDE proposals are granted in slots of between a few months and up to two years.
High-quality tomographic reconstruction
The Scientific Software team and the Engineering, Environmental and Processing (JEEP) beamline (I12) have been developing a high-throughput system for high-quality tomographic reconstruction of large datasets. The use of X-ray tomographic imaging at Diamond has increased dramatically in recent years. Researchers from a broad range of scientific disciplines perform tomographic data collections on large sets of samples or during time-resolved studies and thus collect raw data in a single experiment of several terabytes. Experienced users and non-experts should be able to reconstruct their data during their experimental visit. In order to facilitate this, a standard data and metadata format (NeXus) based upon HDF5 has been adopted at Diamond, and is now in use across all tomography beamlines. The existing reconstruction pipeline (tomo-recon) is currently being replaced by Savu1. This PYTHON 2-based pipeline can output reconstructed files in the NeXuS format, and it is modular; users can control the processing workflow, and new modules can be easily incorporated. Savu is facility-independent in order to serve the growing tomography community at Diamond (beamlines I12, I13 and I18 are operational, and B24 is under construction) and elsewhere.
Figure 1: The XPDF team of scientists, engineers, software scientists and technicians.
Figure 2: The Long Duration Experiment (LDE) facility set up.
Sample environment development
Sample environments are crucial items for experiments at all the Engineering Village beamlines. The success of practically all experiments relies on the flawless in situ conditioning or in situ processing of a wide range of samples. Sometimes sample environments have been developed by the users in their home institutes and are brought to the beamline for their session. However, users often depend on sophisticated equipment for sample conditioning, which is installed at the beamline and integrated into its experimental facilities. Such sample environments are continuously improved and renewed.
By combining online Raman laser spectroscopy with X-ray diffraction, users on I11 can now gain both atomic level structural information and molecular level information. The Horiba Raman system (532 nm lasers, triple grating spectrometer) can be combined with non-contact cooling or heating using the standard capillaries or I11 gas cells. The system operates with both detector systems (position sensitive detector/multi-channel analysers) and has been used successfully during the last year2.
1. Atwood R. et al. A high-throughput system for high-quality tomographic reconstruction of large datasets at Diamond Light Source. Phil. Trans. R. Soc. A 20140398. (2015).
2. Day S. J. et al. In situ apparatus for the study of clathrate hydrates relevant to solar system bodies using synchrotron X-ray diffraction and Raman spectroscopy. Astron. & Astrophy. 574, A91 (2015).
I11’s main station generates powder diffraction patterns with a resolution as high as 10-6 (relative resolution). Samples are usually confined in capillaries and can be subjected to a variety of dynamic environments such as temperature or gas loading.