PEAXIS: A RIXS and XPS Endstation for Solid-State Quantum and Energy Materials at BESSY II

PEAXIS (Photo Electron Analysis and resonant X-ray Inelastic Spectroscopy) is a dedicated endstation installed at the beamline U41-PEAXIS that offers high resolution soft X-ray spectroscopy measurements with incident photon energies ranging from 180 – 1600 eV. The endstation combines two X-ray spectroscopic techniques, X-ray photoelectron spectroscopy (XPS) and resonant inelastic soft X-ray scattering (RIXS), which are important for probing the electronic structure and local and collective excitations of solid-state materials. It features a continuous variation of scattering angle under UHV conditions for wave vector-resolved studies and a modular sample environment that allows investigation in the temperature range between 10 K and 1000 K.

Flexible Sample Environments for the Investigation of Soft Matter at the European Spallation Source: Part III—The Macroscopic Foam Cell

The European Spallation Source (ESS), which is under construction in Lund (Sweden), will be the leading and most brilliant neutron source and aims at starting user operation at the end of 2023. Among others, two small angle neutron scattering (SANS) machines will be operated. Due to the high brilliance of the source, it is important to minimize the downtime of the instruments. For this, a collaboration between three German universities and the ESS was initialized to develop and construct a unified sample environment (SE) system. The main focus was set on the use of a robust carrier system for the different SEs, which allows setting up experiments and first prealignment outside the SANS instruments. This article covers the development and construction of a SE for SANS experiments with foams, which allows measuring foams at different drainage states and the control of the rate of foam formation, temperature, and measurement position. The functionality under ESS conditions was tested and neutron test measurement were carried out.

Flexible Sample Environment for the Investigation of Soft Matter at the European Spallation Source: Part II—The GISANS Setup

The FlexiProb project is a joint effort of three soft matter groups at the Universities of Bielefeld, Darmstadt, and Munich with scientific support from the European Spallation Source (ESS), the small-K advanced diffractometer (SKADI) beamline development group of the Jülich Centre for Neutron Science (JCNS), and the Heinz Maier-Leibnitz Zentrum (MLZ). Within this framework, a flexible and quickly interchangeable sample carrier system for small-angle neutron scattering (SANS) at the ESS was developed. In the present contribution, the development of a sample environment for the investigation of soft matter thin films with grazing-incidence small-angle neutron scattering (GISANS) is introduced. Therefore, components were assembled on an optical breadboard for the measurement of thin film samples under controlled ambient conditions, with adjustable temperature and humidity, as well as the optional in situ recording of the film thickness via spectral reflectance. Samples were placed in a 3D-printed spherical humidity metal chamber, which enabled the accurate control of experimental conditions via water-heated channels within its walls. A separately heated gas flow stream supplied an adjustable flow of dry or saturated solvent vapor. First test experiments proved the concept of the setup and respective component functionality.

Flexible Sample Environments for the Investigation of Soft Matter at the European Spallation Source: Part I—The In Situ SANS/DLS Setup

As part of the development of the new European Spallation Source (ESS) in Lund (Sweden), which will provide the most brilliant neutron beams worldwide, it is necessary to provide different sample environments with which the potential of the new source can be exploited as soon as possible from the start of operation. The overarching goal of the project is to reduce the downtimes of the instruments related to changing the sample environment by developing plug and play sample environments for different soft matter samples using the same general carrier platform and also providing full software integration and control by just using unified connectors. In the present article, as a part of this endeavor, the sample environment for in situ SANS and dynamic light scattering measurements is introduced.

Sample Environment for Operando Hard X-ray Tomography—An Enabling Technology for Multimodal Characterization in Heterogeneous Catalysis

Structure–activity relations in heterogeneous catalysis can be revealed through in situ and operando measurements of catalysts in their active state. While hard X-ray tomography is an ideal method for non-invasive, multimodal 3D structural characterization on the micron to nm scale, performing tomography under controlled gas and temperature conditions is challenging. Here, we present a flexible sample environment for operando hard X-ray tomography at synchrotron radiation sources. The setup features are discussed, with demonstrations of operando powder X-ray diffraction tomography (XRD-CT) and energy-dispersive tomographic X-ray absorption spectroscopy (ED-XAS-CT). Catalysts for CO2 methanation and partial oxidation of methane are shown as case studies. The setup can be adapted for different hard X-ray microscopy, spectroscopy, or scattering synchrotron radiation beamlines, is compatible with absorption, diffraction, fluorescence, and phase-contrast imaging, and can operate with scanning focused beam or full-field acquisition mode. We present an accessible methodology for operando hard X-ray tomography studies, which offer a unique source of 3D spatially resolved characterization data unavailable to contemporary methods.

High-temperature deformation followed in situ by X-ray microtomography: a methodology to track features under large strain

Metallic materials processing such as rolling, extrusion or forging often involves high-temperature deformation. Usually under such conditions the samples are characterized post mortem, under pseudo in situ conditions with interrupted tests, or in situ with a limited strain rate. A full in situ 3D characterization, directly during high-temperature deformation with a prescribed strain-rate scheme, requires a dedicated sample environment and a dedicated image-analysis workflow. A specific sample environment has been developed to enable highly controlled (temperature and strain rate) high-temperature deformation mechanical testing to be conducted while performing in situ tomography on a synchrotron beamline. A dedicated digital volume correlation algorithm is used to estimate the strain field and track pores while the material endures large deformations. The algorithm is particularly suitable for materials with few internal features when the deformation steps between two images are large. An example of an application is provided: a high-temperature compression test on a porous aluminium alloy with individual pore tracking with a specific strain-rate scheme representative of rolling conditions.