Diamond Concise Annual Review 2021/22

22 23 D I A M O N D L I G H T S O U R C E A N N U A L R E V I E W 2 0 2 1 / 2 2 D I A M O N D L I G H T S O U R C E A N N U A L R E V I E W 2 0 2 1 / 2 2 Imaging andMicroscopy Group T he Imaging andMicroscopy Group brings together eight experimental facilities (I08, I08-1, DIAD, I12, I13-1, I13-2, I14 and the electron Physical Science Imagine Centre [ePSIC]), which use electrons and X-rays to image samples under different experimental conditions across a diverse range of length scales and time scales. The soft X-ray ptychography branchline I08-1 and DIAD the dual imaging and diffraction beamline entered their first year of operations. Together, these beamlines bring new world-leading tools to the imaging community, and we are entering an exciting phase of designing and performing new experiments with the user community which exploit these new capabilities. The ability to extract image sample properties in minute detail lends itself to a wide range of scientific areas, from chemistry and catalysis to environmental science, materials science, biology, medicine, and cultural heritage. Studies from the group this year include those to improve the design and efficiency of semiconductors and optoelectronics used in many devices, and solid-state batteries for electric vehicles. Improving semiconductor efficiency Lead halide perovskites are a family of synthetic semiconductor materials used for solar panels, LEDs, displays, sensors, and many other applications. However, these materials have limited stability over time and can leach toxic chemicals into theenvironment. For example, CsPbI 3 is sensitive to temperature, air, light, and water, limiting its practical applications. An international team of researchers addressed this challenge by encapsulating the material in a matrix made of a new type of glass derived from metal-organic frameworks, using a technique called liquid phase sintering. The composite showed orders of magnitude higher efficiency for light emission and significantly enhanced stability, providing high-quality light for more than a year. The research team used advanced tools to understand the new material’s performance. They used the E02 microscope at ePSIC to see individual nanometre scale crystals and determine the type of crystal within the glass. They also used Scanning Transmission Electron Microscopy (STEM) to examine the material and document how the glass preserves and locks in the correct, light-emitting perovskite crystals. These results explain how to make long- lasting light-emitting glass composites, while preventing toxic lead leaching and improving the mechanical properties of the material to prevent breakage. Hou J et al. DOI: 10.1126/science.abf4460 DOI: 10.1126/science.abf4460 Refining solid-state battery design High energy density solid-state batteries, with ceramic solid electrolytes and lithium metal anodes, promise to address the range anxiety and safety issues associated with current electric vehicles. However, practical application of solid-state batteries is limited by electrolyte cracking and short circuits at high charging rates due to the propagation of lithium filaments called dendrites through the ceramic electrolyte. An international team led by the University of Oxford conducted a study aimed at improving the design of ceramic electrolytes to provide fast-charging solid-state batteries. They used beamline I12 to image dendrite-induced cracks using high spatial resolution X-ray Computed Tomography (XCT) and located lithium dendrites by spatially mapped X-ray diffraction. This combination of techniques provided reliable evidence of the correlation between cracks and dendrite growth into the cracks and showed the exact cause of the short circuits seen in these batteries at high charging rates. This work suggests that an effective way to prevent dendrite growth in solid-state batteries is to inhibit the development of dry cracks in the ceramic electrolyte. Therefore, strategies that toughen the ceramic electrolyte, such as fibre reinforcement and transformation toughening, may help to enable fast- charging, safe and highly energy-dense solid-state batteries. Ning Z et al. DOI: 10.1038/s41563-021-00967-8 Improving anticancer drugs Transition metal catalysts have potential as therapeutic agents to treat cancer and other diseases. However, there is a need to improve the design of these catalysts tomake themmore efficient, so they can be used in lower doses, and hasten progress towards clinical use. Researchers from the University of Warwick have designed a series of advanced organo-osmium catalysts that can transform an essential ketone in cell metabolism inside cancer cells. This can cause selective destruction of cancer cells, but not healthy cells. Using synchrotron X-ray Fluorescence, researchers can track the catalysts in cancer cells and observe how long they remain intact and active. The Hard X-Ray Nanoprobe beamline (I14) allowed the team to study biological samples with a range of X-ray imaging and spectroscopic techniques using a nano-focused photon beam. This provided valuable insight into the distribution and chemical properties of the metal complexes inside cells. The results obtained suggest a strategy for improving the design of catalytic organo-osmium anticancer drugs. This work also demonstrated the wider potential of experimental approaches using X-ray based techniques for the fields of chemical biology and medicinal chemistry. This approach can contribute to the design and development of new classes of transition metal complexes as therapeutic and biotechnological tools. Bolitho EM et al. DOI: 10.1002/anie.202016456