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Small‐angle X‐ray tensor tomography and the related wide‐angle X‐ray tensor tomography are X‐ray imaging techniques that tomographically reconstruct the anisotropic scattering density of extended samples. In previous studies, these methods have been used to image samples where the scattering density depends slowly on the direction of scattering, typically modeling the directionality, i.e. the texture, with a spherical harmonics expansion up until order ℓ = 8 or lower. This study investigates the performance of several established algorithms from small‐angle X‐ray tensor tomography on samples with a faster variation as a function of scattering direction and compares their expected and achieved performance. The various algorithms are tested using wide‐angle scattering data from an as‐drawn steel wire with known texture to establish the viability of the tensor tomography approach for such samples and to compare the performance of existing algorithms. [ABSTRACT FROM AUTHOR]

This study characterizes the microstructure and mineralogy of 132 (ODP sample), 1000 and 1880 million‐year‐old chert samples. By using ultra‐small‐angle X‐ray scattering (USAXS), wide‐angle X‐ray scattering and other techniques, the preservation of organic matter (OM) in these samples is studied. The scarce microstructural data reported on chert contrast with many studies addressing porosity evolution in other sedimentary rocks. The aim of this work is to solve the distribution of OM and silica in chert by characterizing samples before and after combustion to pinpoint the OM distribution inside the porous silica matrix. The samples are predominantly composed of alpha quartz and show increasing crystallite sizes up to 33 ± 5 nm (1σ standard deviation or SD). In older samples, low water abundances (∼0.03%) suggest progressive dehydration. (U)SAXS data reveal a porous matrix that evolves over geological time, including, from younger to older samples, (1) a decreasing pore volume down to 1%, (2) greater pore sizes hosting OM, (3) decreasing specific surface area values from younger (9.3 ± 0.1 m2 g−1) to older samples (0.63 ± 0.07 m2 g−1, 1σ SD) and (4) a lower background intensity correlated to decreasing hydrogen abundances. The pore‐volume distributions (PVDs) show that pores ranging from 4 to 100 nm accumulate the greater volume fraction of OM. Raman data show aromatic organic clusters up to 20 nm in older samples. Raman and PVD data suggest that OM is located mostly in mesopores. Observed structural changes, silica–OM interactions and the hydrophobicity of the OM could explain the OM preservation in chert. [ABSTRACT FROM AUTHOR]

Characterization of the mechanical response of polymers and composite materials relies heavily on the macroscopic stress–strain response in uniaxial tensile configurations. To provide representative information, the deformation process must be homogeneous within the gauge length, which is a condition that is rarely achieved due to stress concentration or inhomogeneities within the specimen. In this work, the development of a biaxial mechanical testing device at the CoSAXS beamline at MAX IV Laboratory is presented. The design facilitates simultaneous measurement of small‐ and wide‐angle X‐ray scattering (SAXS/WAXS), allowing assessment of the microstructural configuration before, after and during the continuous deformation process at multiple length scales. The construction also supports multiple deformation conditions, while guaranteeing stability even at high loads. Furthermore, the mechanical experiments can be complemented with spatially resolved mesoscopic surface deformation measurements using 3D‐surface digital image correlation (DIC). Polycarbonate (PC) was used to demonstrate the varied material response to multi‐axial deformation, as PC is isotropic with a high glass transition temperature (∼150°) and high strength. As a result, a clear correlation between full‐field methods and the microstructural information determined from WAXS measurements is demonstrated. When a uniaxial load is applied, homogeneous strain regions could be observed extending perpendicular to the applied load. When a secondary axial load was added (biaxial mode), it was observed that high strain domains were created near the centre of the sample and at the boundaries after yield. With increased strain, the deformation in the main deformation direction also increases. Mechanical reliability was demonstrated by carrying out static loading of polyacrylonitrile‐based carbon fibre (CF) bundles. As a result, the nonlinear stiffening behaviour typically observed in CFs was seen, while no evidence of the creation of new voids during loading was observed. The results support the reliability and broad applicability of the developed technique. [ABSTRACT FROM AUTHOR]

Finite size effects in partial pair distribution functions generate artefacts in the scattering structure factor and scattering intensity. It is shown how they can be overcome using a binned version of the Debye scattering equation. Accordingly, reverse Monte Carlo simulations are used for very small nanoparticles of LaFeO3 with diameters below 10 nm to simultaneously analyse X‐ray scattering data and extended X‐ray absorption fine structure spectra at the La K and Fe K edges. The structural information obtained is consistent regarding local structure and long‐range order. [ABSTRACT FROM AUTHOR]

A new tomographic reconstruction algorithm is presented, termed direct least‐squares reconstruction (DLSR), which solves the well known parallax problem in X‐ray‐scattering‐based experiments. The parallax artefact arises from relatively large samples where X‐rays, scattered from a scattering angle 2gθ, arrive at multiple detector elements. This phenomenon leads to loss of physico‐chemical information associated with diffraction peak shape and position (i.e. altering the calculated crystallite size and lattice parameter values, respectively) and is currently the major barrier to investigating samples and devices at the centimetre level (scale‐up problem). The accuracy of the DLSR algorithm has been tested against simulated and experimental X‐ray diffraction computed tomography data using the TOPAS software. [ABSTRACT FROM AUTHOR]

X-ray scattering (XRS) experiments have been performed on multi-layered graphene oxide (GO) paper. GO can be easily hydrated as water naturally intercalates in the hydrophilic nanostructure. The effect of the intercalated water on the XRS signals is measured during dehydration under thermal treatment in the temperature range 298-473 K as well as during hydration under saturated water vapour pressure. A simple modelling of the XRS signals by taking into account the presence and the type of intercalated water (bound water or physisorbed water) is introduced. It allows an explanation of the variations of intensity and position of XRS reflections observed experimentally. [ABSTRACT FROM AUTHOR]

A SWAXS (small- and wide-angle X-ray scattering) instrument was recently installed at the wiggler beamline BL17B3 of the National Synchrotron Radiation Research Center (NSRRC), Taiwan. The instrument, which is designed for studies of static and dynamic nanostructures and correlations between the nano (or meso) structure (SAXS) and crystalline structure (WAXS), provides a flux of 1010–1011 photon s−1 at the sample at energies between 5 and 14 keV. With a SAXS area detector and a WAXS linear detector connected to two data acquisition systems operated in master–slave mode, the instrument allows one to perform time-resolved as well as anomalous scattering measurements. Data reduction algorithms have been developed for rapid processing of the large SWAXS data sets collected during time-resolved measurements. The performance of the instrument is illustrated by examples taken from different classes of ongoing projects: (i) time-resolved SAXS/WAXS/differential scanning calorimetry (DSC) with a time resolution of 10 s on a semicrystalline poly(hexamethylene terephthalate) sample, (ii) anomalous SAXS/WAXS measurements on a nanoparticulate PtRu catalyst, and (iii) grazing-incidence SAXS of a monolayer of oriented semiconductor quantum wires, and humidity-controlled ordering of Alamethicin peptides embedded in an oriented lipid membrane. [ABSTRACT FROM AUTHOR]

The wide-angle scattering of X-rays (WAXS) by anisotropic powders of nano-layered crystallites (nano-stacks) is addressed. Assuming that the orientation distribution probability function f of the nano-stacks only depends on the deviation of the crystallites' orientation from a fixed reference direction, a relation providing f from the dependence of a given diffraction peak's amplitude on the azimuthal angle is derived. The method is applied to two systems of sodium fluorohectorite (NaFH) clay particles, using synchrotron radiation and a WAXS setup with a two-dimensional detector. In the first system, which consists of dry-pressed NaFH samples, the orientation distribution probability function corresponds to a classical uniaxial nematic order. The second system is observed in bundles of polarized NaFH particles in silicon oil; in this case, the nano-stacks have their directors, on average, in a plane normal to the reference direction, and f is a function of the angle between a nano-stack's director and that of the plane. In both cases, a suitable Maier–Saupe function is obtained for the distributions, and the reference direction is determined with respect to the laboratory frame. The method only requires one scattering image. Consistency can be checked by determining the orientation distribution from several diffraction peaks independently. [ABSTRACT FROM AUTHOR]

At the beamlines ID01 and ID02 of the European Synchrotron Radiation Facility in Grenoble, France, position-sensitive detectors for time-resolved small- and wide-angle X-ray scattering experiments are in use. The applied data reduction method has never been described comprehensively. This article outlines the parametrization of the raw data and introduces the programs developed for this purpose. Data reduction in the sense of this article means all steps between detector readout and normalization to absolute scattering intensities. This includes all corrections that can be made without any specific knowledge of the sample, e.g. detector dark-image correction, division by a flat-field and intensity normalization. Processed data are either two- or one-dimensional. Optionally, statistical errors can be propagated through the calculations. [ABSTRACT FROM AUTHOR]

The residual orientation following micro-injection molding of small rectangular plates with linear polyethylene has been examined using small-angle neutron scattering, and small- and wide-angle X-ray scattering. The effect of changing the molding conditions has been examined, and the residual chain orientation has been compared to the residual orientation of the crystallites as a function of position in the sample. This study has found that, for micromoldings, the orientation of the crystallites decreases with increasing injection speed and increasing mold thickness. The combined data suggest that the majority of the orientation present comes from oriented crystal growth rather than residual chain orientation. [ABSTRACT FROM AUTHOR]

Based on high statistical quality wide-angle X-ray scattering data for the unfolding–refolding process of hen egg-white lysozyme (HEWL), we have analysed the change of the hydration shell as a function temperature using the program CRYSOL. The present results suggest that the decrease of the hydration-shell density starts from a lower temperature than the transition temperature of the collapse of the tertiary structure of HEWL. Although the use of CRYSOL for scattering data for proteins before the transition has an apparent limitation, the collapse of the hydration shell prior to the unfolding of HEWL agrees with a slight tendency of the radius of gyration to decrease during the thermal unfolding process. [ABSTRACT FROM AUTHOR]