Two recently developed experimental devices for investigating soft matter deformation are presented. Both devices exploit the capabilities of a modern synchrotron beamline to enable advanced and highly precise materials-science experiments in which X-ray scattering is registered. The devices can be operated both in monotonic as well as cyclic mode and are implemented into a beamline at DESY , Hamburg (Germany). Hence, relevant experimental parameters, such as displacement, force and temperature, are recorded synchronously with the individual X-ray scattering patterns. In addition, spatial variation of materials deformation can be monitored and recorded with optical microscopy. This unique sample environment enables in situ X-ray experiments in transmission, i.e. small- or wide-angle X-ray scattering (SAXS or WAXS), and in grazing-incidence geometry, i.e. grazing-incidence (GI-) SAXS or WAXS. One device with stepper motors is designed for studies of slow, (quasi-) static deformation and the other one with pneumatic actuators can be used for fast, impact deformation. Both devices are available to external beamline users, too.

Sputter deposition is a versatile and industrially important deposition technique for thin films, with increasing demand for matching the characteristics of thin film materials to specific requirements. The actual film properties are largely determined by sputtering parameters such as pressure conditions, temperature and power settings. By means of various X-ray diffraction and scattering techniques, it is shown that the characterization of film formation and growth is feasible in real time at synchrotron sources, thus adding an important dimension to the fundamental understanding of the evolution of thin film microstructure. In particular, grazing incidence small-angle X-ray scattering, grazing incidence X-ray powder diffraction and X-ray reflectometry are used in a complementary manner to study the influence of deposition temperature and substrate choice on the crystallization kinetics and growth of polycrystalline BaTiO$$_3$$ films.

Fe-based metallic glasses (MGs) are known to exhibit excellent soft magnetic properties. A very effective way to further improve their magnetic properties is to incorporate nanocrystals into the glassy matrix. Usually it is done by conventional annealing in the vicinity of primary crystallization temperature. Direct current fast Joule heating (flash-annealing) represents an alternative way to introduce fine and randomly dispersed nanocrystals within MGs. Achieving high heating/cooling rates (well above 1000 degrees C/s) by flash-annealing opens up new possibilities for study the fast kinetics. Phase composition and microstructure of a material can be tailored by proper heat-treatment in order to improve its overall performance. In this paper, we introduce a novel setup for studying rapid crystallization of metallic glasses using an in situ X-ray diffraction flash-annealing.

Fast compression experiments performed using dynamic diamond anvil cells (dDACs) employing piezoactuators offer the opportunity to study compression-rate dependent phenomena. In this paper, we describe an experimental setup which allows us to perform time-resolved x-ray diffraction during the fast compression of materials using improved dDACs. The combination of the high flux available using a 25.6 keV x-ray beam focused with a linear array of compound refractive lenses and the two fast GaAs LAMBDA detectors available at the Extreme Conditions Beamline (P02.2) at PETRA III enables the collection of x-ray diffraction patterns at an effective repetition rate of up to 4 kHz. Compression rates of up to 160 TPa/s have been achieved during the compression of gold in a 2.5 ms fast compression using improved dDAC configurations with more powerful piezoactuators. The application of this setup to low-Z compounds at lower compression rates is described, and the high temporal resolution of the setup is demonstrated. The possibility of applying finely tuned pressure profiles opens opportunities for future research, such as using oscillations of the piezoactuator to mimic propagation of seismic waves in the Earth.

Synchrotrons can provide very intense and focused X-ray beams, which can be used to study the structure of matter down to the atomic scale. In many experiments, the quality of the results depends strongly on detector performance; in particular, experiments studying dynamics of samples require fast, sensitive X-ray detectors. "LAMBDA" is a photon-counting hybrid pixel detector system for experiments at synchrotrons, based on the Medipix3 readout chip. Its main features are a combination of comparatively small pixel size (55 mu m), high readout speed at up to 2000 frames per second with no time gap between images, a large tileable module design, and compatibility with high-Z sensors for efficient detection of higher X-ray energies. A large LAMBDA system for hard X-ray detection has been built using Cr-compensated GaAs as a sensor material. The system is composed of 6 GaAs tiles, each of 768 by 512 pixels, giving a system with approximately 2 megapixels and an area of 8.5 by 8.5 cm(2). While the sensor uniformity of GaAs is not as high as that of silicon, its behaviour is stable over time, and it is possible to correct nonuniformities effectively by postprocessing of images. By using multiple 10 Gigabit Ethernet data links, the system can be read out at the full speed of 2000 frames per second. The system has been used in hard X-ray diffraction experiments studying the structure of samples under extreme pressure in diamond anvil cells. These experiments can provide insight into geological processes. Thanks to the combination of high speed readout, large area and high sensitivity to hard X-rays, it is possible to obtain previously unattainable information in these experiments about atomic-scale structure on a millisecond timescale during rapid changes of pressure or temperature.

Ultra-small clusters containing few atoms are of high interest in both fundamental research and applications due to their specific functional, magnetic or chemical properties which depend on size and composition. The experimental results of the morphology of the size-selected clusters, consisting of few atoms can be an ideal benchmark for sophisticated theoretical models. With this motivation we have investigated the geometrical structure of mass-selected Au-9 clusters deposited on a silicon substrate prepared by soft-landing conditions. We present results obtained experimentally by Grazing-Incidence Small-Angle X-ray Scattering (GISAXS). Considering the ultra-small size of the clusters and small quantities of material on the surface, we combined advanced techniques which allowed us to investigate the surface structure of the sample. The resulting structural sizes are in concordance with cluster theory. Using a model-based approach, the advanced X-ray techniques allow for understanding how to resolve the possible cluster structure, identify optimal experimental conditions and obtain the probable morphological information which is challenging to be obtained otherwise.

We experimentally determined the bulk modulus of (Mg0.8Fe0.2)O ferropericlase across the iron spin transition and in the low-spin phase by employing a new experimental approach. In our measurements, we simulate the propagation of a compressional seismic wave (P wave) through our sample by employing a piezo-driven dynamic diamond anvil cell that allows to oscillate pressure at seismic frequencies. During pressure oscillations, X-ray diffraction images were continuously collected every 5-50 ms. The bulk modulus is directly calculated from these data at different pressures. Our experiments show a pronounced softening of the bulk modulus throughout the spin crossover, supporting previous single-crystal measurements at very high frequencies and computations. Comparison of our results to previous data collected on (Mg,Fe)O with lower iron contents shows that the magnitude of softening strongly depends on iron content. Our experiments at seismic frequencies confirm that the iron spin crossover markedly affects the ratio of seismic compressional to shear wave velocities in Earth's lower mantle. Plain Language Summary Information about the structure and composition of Earth's mantle can be derived from comparison of measured seismic wave speeds to those predicted from laboratory sound wave velocity measurements at high pressures. Ferropericlase, the second most abundant mineral in Earth's lower mantle, changes its electronic configuration at pressures corresponding to the lower mantle. Laboratory measurements carried out at very high frequencies (GHz) indicate that this so-called spin transition significantly decreases compressional wave velocities. If true, this effect can affect our interpretation of seismological observables. However, experimental results are partly in disagreement and no measurements have been conducted at typical seismic frequencies that are much lower as those typical for laboratory experiments. In this work. we directly measured the effect of the iron spin transition on the elastic response of ferropericlase at a frequency of 1 Hz. We find a significant softening effect on the bulk modulus that will lead to a decrease of compressional seismic velocities in Earth's lower mantle. Based on comparison of our results to previous work, we show that the effect strongly depends on iron content.

Strain Induced Crystallization (SIC) is one of the special features of Natural Rubber (NR), responsible for its outstanding mechanical performance. Especially, for the short term behavior of NR, e.g. within a rolling tire, the kinetics of SIC plays an important role. SIC can be observed to some extend by thermography, but it is not directly possible to separate the heating effects accompanying SIC from dissipative heating of the rubber material (LeCam et al., 2015, Spratte et al., 2017). By means of synchrotron x-ray diffraction, SIC can be monitored during deformation including cyclic deformations and impact loading with a time resolution of less than 10 ms (Bruning et al., 2013). Combining this method with thermography enables the separation of processes of structure formation and dissipation. This can serve as a basis for a more realistic modelling of the dynamic and thermomechanical behavior of natural rubber.Within the presentation we report about investigations of cyclic loadings of differently Carbon Black (CB) filled NR samples with respect to SIC, melting of the crystallites as well as the dissipative heating and convective cooling of the rubber materials.

X-ray absorption spectroscopy on dilute samples is still a challenge nowadays. By means of the fluorescence processes that follow the absorption it is possible to obtain the XAS spectrum; however, in order to gain sufficient statistics a multi-pixel fluorescence detector is required. A 100 pixel Ge detector will be available at beamline P64 at PETRA III for ultra dilute sample systems. Here, we propose a method of data reduction that resolves the line of interest from the scattering peak, improving the signal-to-noise ratio of the final XAS spectrum compared with the one obtained with a simple region of interest (ROI).

A detailed description is presented of the Extreme Conditions Beamline P02.2 for micro X-ray diffraction studies of matter at simultaneous high pressure and high/low temperatures at PETRA III, in Hamburg, Germany. This includes performance of the X-ray optics and instrumental resolution as well as an overview of the different sample environments available for high-pressure studies in the diamond anvil cell. Particularly emphasized are the high-brilliance and high-energy X-ray diffraction capabilities of the beamline in conjunction with the use of fast area detectors to conduct time-resolved compression studies in the millisecond time regime. Finally, the current capability of the Extreme Conditions Science Infrastructure to support high-pressure research at the Extreme Conditions Beamline and other PETRA III beamlines is described.

The melting of bismuth in response to shock compression has been studied using in situ femtosecond x-ray diffraction at an x-ray free electron laser. Both solid-solid and solid-liquid phase transitions are documented using changes in discrete diffraction peaks and the emergence of broad, liquid scattering upon release from shock pressures up to 14 GPa. The transformation from the solid state to the liquid is found to occur in less than 3 ns, very much faster than previously believed. These results are the first quantitative measurements of a liquid material obtained on shock release using x-ray diffraction, and provide an upper limit for the time scale of melting of bismuth under shock loading.

1DESY, Notkestr. 85, 22607 Hamburg, Germany, 2CFEL at DESY, Notkestr. 85, 22607 Hamburg, Germany, 3Institute of Experimental Physics, University of Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany, 4SLAC National Accelerator Laboratory, 2575 Sand Hill Road MS 29, Menlo Park, CA 94025, USA, 5Faculty of Physics, University of Bialystok, ul. Lipowa 41, 15-424 Bialystok, Poland, 6European XFEL GmbH, Notkestr. 85, 22607 Hamburg, Germany, 7University of Canterbury, Christchurch 8140, New Zealand

In quantum mechanics the Young-type double-slit experiment can be performed with electrons either traveling through a double slit or being coherently emitted from two inversion symmetric molecular sites. In the latter one the valence photoionization cross sections of homonuclear diatomic molecules were predicted to oscillate over kinetic energy almost 50 years ago. Beyond the direct proof of the oscillatory behavior of these photoionization cross sections σ, we show that the angular distribution of the emitted electrons reveals hitherto unexplored information on the relative phase shift between the corresponding partial waves through two-center interference patterns.

With the continual drive towards bigger, better, and brighter light sources, whole new areas of scientific research are possible that would have been unimaginable or even were believed impossible before. For example, imaging of single bioparticles has been demonstrated at Free Electron Lasers (FELs) [1 M. Seibert, Nature 470, 78–81 (2011).[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]], and synchrotron beamlines can now be used to study real-time changes in samples on a timescale of milliseconds.

High-frame-rate X-ray pixel detectors make it possible to perform time-resolved experiments at synchrotron beamlines, and to make better use of these sources by shortening experiment times. LAMBDA is a photon-counting hybrid pixel detector based on the Medipix3 chip, designed to combine a small pixel size of 55 μm, a large tileable module design, high speed, and compatibility with ``high-Z'' sensors for hard X-ray detection. This technical paper focuses on LAMBDA's high-speed-readout functionality, which allows a frame rate of 2000 frames per second with no deadtime between successive images. This takes advantage of the Medipix3 chip's ``continuous read-write'' function and highly parallelised readout. The readout electronics serialise this data and send it back to a server PC over two 10 Gigabit Ethernet links. The server PC controls the detector and receives, processes and stores the data using software designed for the Tango control system. As a demonstration of high-speed readout of a high-Z sensor, a GaAs LAMBDA detector was used to make a high-speed X-ray video of a computer fan.

We have designed a portable pressure controller module to tune compression rates and maximum pressures attainable in a standard gas-membrane diamond anvil cell (DAC).During preliminary experiments, performed on zirconium (Zr) metal sample, pressure jumps of up to 80 GPa were systematically obtained in less than 0.2s (resulting in compression rate of few GPa/s up to more than 400 GPa/s).In-situ x-ray diffraction and electrical resistance measurements were performed simultaneously during this rapid pressure increase to provide the first time resolved data on α → ω → β structural evolution in Zr at high pressures.Direct control of compression rates and peak pressures, which can be held for prolonged time, allows for investigation of structural evolution and kinetics of structural phase transitions of materials under previously unexplored compression rate-pressure conditions that bridge traditional static and shock/dynamic experimental platforms.

Phenylene-bridged periodic mesoporous organosilica (PMO) materials with hexaethylene glycol mono hexadecylether (C16(EO)6) as structure directing agent (SDA) in acidic solution were synthesised and the reaction was studied in different conditions, including in situ small angle X-ray scattering at room temperature and at 60 °C. The in situ SAXS investigations at 60 °C show the formation of a 2D hexagonal mesostructure after 3 hours reaction time. In contrast to these results the same reaction performed in the laboratory produced a powder that, after drying at room temperature, shows a large number of diffraction peaks, allowing identifying a lamellar structure, possibly in coexistence of a micellar cubic structure (space group Pm3n). Aposteriori removal of the surfactant from the powder synthesised in the laboratory led to the collapse of the lamellar structure.