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at the L3-edge of lead to discover novel charge ordering and a spin reorientation transition in the perovskite PbFeO3 (page 114).
Beamline ID26 is the first ESRF spectroscopy beamline to fully run under the new beamline operation software, BLISS, which uses Python programming. Changing the beamline operation software is tantamount to recommissioning most parts of the beamline because operation and performance of the beamline, including alignment, stabilisation and data acquisition, are intricately intertwined with the software running it. Doing this with software that is being developed presented a formidable task for the staff. The beamline achieved stable operation in 2021 and started to explore the fantastic possibilities of Python for beamline operation and online data treatment. Some work remains to be done in 2022 with respect to user-friendliness. The beamline furthermore worked on the mechanics of the double-crystal monochromator in order to improve beam position stability over the XAS scanning range. The selected articles show how birds detoxify Hg (page 109) and how enzymes can inspire artificial catalysts (page 117).
ID32 has seen a gradual transition from remote user operation to mostly onsite experiments. Scientists being at the beamline instead of remotely following the experiment allows a much wider variety of experiments to be run, in particular, those that need sample preparation at the beamline mostly on the XMCD branch. Nevertheless, despite the disruptions of the past year, many interesting experiments were carried out. In addition, important papers on the effect of strain on high-temperature superconductors (HTc) were published, as can be seen in the articles below. One of the studies finds that by using uniaxial in-plane compression, one can enhance the charge density waves (CDW) in an HTc in the direction perpendicular to the strain, confirming its uniaxial character (page 111). The second study uses
strain induced in an HTc ultra-thin film from the substrate, resulting in an expansion in the b-direction (page 118). This causes a suppression of the CDW in the a-direction. By linking these observations with extensive angular- dependant resistivity measurements, the results show a striking anisotropic behaviour of the so-called strange metal phase of high-temperature superconductors and sheds important new light on the nature of this phase out of which high-temperature superconductivity emerges. Both these investigations show that studies of CDWs using Resonant Inelastic X-ray Scattering (RIXS) can add important new information in the still-puzzling field of high-temperature superconductivity.
During the first semester of 2021, the sample environment unit was fully dedicated to user experiment preparation and repairs of beamline equipment. During the second semester, several user experiments required new prototypes of instruments. The unit developed a system for large samples at high pressure for ID31, allowing liquids to be measured up to 4000 bars at -130°C. Another system developed for ID09 allows a continuous liquid jet containing a mixture of microcrystals and liquids to be flash cryo-cooled close to the freezing point of the liquid (here -80°C) and immediately warmed up to room temperature continuously over hours while recording data. A first prototype of a cell for XAS operando measurements of a 5 mm pellet was developed for BM23, allowing measurement at 800°C with no dead volume of gas. Finally, the unit developed a new furnace that allows a half-sphere view of a sample with thin, 16-micron Kapton, without a blind spot. This furnace allows the measurement of samples in reflection geometry at 1000°C in atmosphere. Thanks to a 3D-printed body in stainless steel, this furnace is very compact and offers excellent spatial and thermal stability over its full operating range
P. GLATZEL, A. ROGALEV, C. SAHLE, N. BROOKES AND Y. WATIER
