Recovering local structure information from high-pressure total scattering experiments

A method for subtracting the pairwise correlations of a pressure-transmitting medium from neutron pair distribution functions obtained under hydro­static compression is presented and applied to Ni, MgO and α-quartz.

Geometrical-optics formalism to model contrast in dark-field X-ray microscopy

A formalism is presented for simulating dark-field X-ray microscopy images. Using geometrical optics, it allows direct coupling to mechanical models.

Probabilistic parameter estimation using a Gaussian mixture density network: application to X-ray reflectivity data curve fitting

A mixture density network (MDN), a neural network method that can make probabilistic predictions, is applied to X-ray reflectivity data analysis. The probability distribution of several possible parameters obtained using an MDN can help estimate the confidence interval and solve the inverse problem.

Multiple scattering and resolution effects in small-angle neutron scattering experiments calculated and corrected by the software package MuScatt

Calculations and desmearing of different multiple scattering effects for the small-angle scattering technique using the software package MuScatt are presented.

Symmetry and chirality in crystals

The symmetry requirements and restrictions for the existence of chiral crystal structures are analysed.

Estimating electron density at the bond critical point through atomic Hirshfeld surfaces

The relation between the electron density at the bond critical point estimated using the quantum theory of atoms in molecules and the curvature of atomic Hirshfeld surfaces is explored empirically through the curvedness property at particular points on these surfaces.

Iterative diffraction pattern retrieval from a single focal construct geometry image

A general iterative algorithm is proposed, to recover the X-ray diffraction data from a single focal construct geometry image, allowing the focal construct geometry to increase the diffraction intensity while simultaneously preserving the angular resolution.

High-accuracy polarimetric studies on lead germanate single crystals

The electro-optical and gyration parameters of a lead germanate ferroelectric single crystal in the direction perpendicular to the optical axis have been investigated by a high-accuracy polarimetric technique.

A self-consistent approach to describe unit-cell-parameter and volume variations with pressure and temperature

A method is presented for the self-consistent description of the variations of unit-cell parameters of crystals with pressure and temperature.

Evaluation of sample cell materials for aqueous solutions used in quasi-elastic neutron scattering measurements

For aqueous solutions in quasi-elastic neutron scattering (QENS) studies, Al alloys with higher Al content, boehmite coating, reduced surface area and reduced concentrations of dissolved oxygen tended to be resistant to corrosion. QENS measurements of the empty sample cells revealed that (1) the profile of the cell fabricated with copper-free Al alloy showed a minor scattering vector dependence and (2) reducing the real surface area of the Al surface effectively suppresses its scattering intensity.

The structural and magnetic properties of single-crystal Gd₄Ga₂O₉

The single-crystal growth of Gd₄Ga₂O₉ with the optical floating zone technique is reported. Structural information has been obtained through powder X-ray diffraction combined with Rietveld refinement. Magnetic susceptibility and heat capacity measurements suggest an antiferromagnetic phase transition and strong magnetic frustration characteristics.

Neutron diffraction investigation of copper tellurite glasses with high real-space resolution

The structure of copper tellurite glasses has been investigated by neutron diffraction.

Hidden and apparent twins in uranyl-oxide minerals agrinierite and rameauite: a demonstration of metric and reticular merohedry

Two examples of twinning, by metric and reticular merohedry, in uranyl-oxide minerals demonstrate the care that must be taken during structural studies, and not only of such complex materials. This contribution also demonstrates the possibilities of the Jana2020 program in revealing twinning and in subsequent refinement.

Theoretical and computational improvements to the algebraic method for discovering cooperative rigid-unit modes

The linear-algebraic approach to finding cooperative rigid-unit modes in interconnected networks has been greatly improved.

Fisher information for optimal planning of X-ray diffraction experiments

An approach for optimizing the measurement configuration in X-ray diffraction by maximization of Fisher information is proposed. The developed technique is applied to high-resolution X-ray diffraction measurements and microstructure analysis.

BioSAXS on the SWING beamline at Synchrotron SOLEIL

This article describes recent developments on the SWING beamline for biological small-angle X-ray scattering (BioSAXS) experiments.

In situ small-angle X-ray scattering investigation of X-ray-induced gold nanoparticle synthesis without stabilizer

The X-ray irradiation of gold salt aqueous solutions in the synthesis of gold nanoparticles (AuNPs) in the absence of any reducing agent and stabilizer has been followed by in situ small-angle X-ray scattering. The key parameters to obtain stable, monodispersed, bare AuNPs and the influence of the pH of the chemical solution on the final particles were studied.

Signature of antiphase boundaries in iron oxide nanoparticles

Antiphase boundaries (APBs) in iron oxide nanoparticles are studied by means of simulations. A strong influence on the spin structure is determined with Monte Carlo simulations, while hkl-dependent peak broadening useful for identifying APBs in real samples is found from Debye scattering equation simulations.

Optimizing the geometry of aerodynamic lens injectors for single-particle coherent diffractive imaging of gold nanoparticles

An optimization procedure of an aerodynamic lens injector with variable geometry is presented. The simulation results are validated by performing experiments on gold and sucrose nanoparticles. This work is envisioned to be an important step towards high-resolution single-particle imaging.

Development and performance evaluation of a multi-layer boron-lined detector for the CPHS-SANS instrument

A position-sensitive thermal neutron detector module which is based on multi-layer boron-lined tubes has been developed for the CPHS-SANS instrument. Several aspects of the detector module have been evaluated by simulation and experiment.

Intrinsic roughness and interfaces of Cr/Be multilayers

The paper shows the overall quality of Cr/Be X-ray multilayer mirrors and gives estimated values of roughness and material intermixing separately.

Evolution of laser-induced strain in a Ge crystal for the [111] and [100] directions probed by time-resolved X-ray diffraction

Laser-induced strain propagation in a Ge crystal is studied using time-resolved X-ray diffraction.

Ce-exchange capacity of zeolite L in different cationic forms: a structural investigation

Zeolite L was Na- and NH₄-exchanged and the resulting samples were characterized by structural and chemical analyses. From the perspective of the possible use of zeolite L for rare earth element recovery (in particular Ce) and to unveil the differences in the affinity for Ce dictated by the presence of different counter-cations, the three samples with LTL framework type were Ce³⁺-exchanged and fully characterized.

Insights into the mechanism of high lipid–detergent crystallization of membrane proteins

High lipid–detergent crystallization of two model membrane proteins, MhsT and SERCA1a, where the effects of varying lipid/detergent ratio were tested, and the resulting lipid phases and crystals were studied using electron microscopy, providing insights into the crystallization mechanism.

Artifact removal in the contour areas of SAXS-CT images by Tikhonov-L1 minimization

Small-angle X-ray scattering (SAXS) coupled with computed tomography (CT), denoted SAXS-CT, enables the spatial distribution of the characteristic parameters of nanoscale structures inside samples to be visualized. In this work, a new scheme with Tikhonov regularization was developed to remove the effects of artifacts caused by streak scattering originating from contour regions of the sample.

Evaluation of extremely steep residual stress gradients based on a combined approach using laboratory-scale equipment

This paper reports on high-resolution analysis of residual stress gradients for a laser-hardened surface layer using a combined angle-dispersive X-ray diffraction approach that applies the universal plot method and sin²Ψ evaluation.

Automated prediction of lattice parameters from X-ray powder diffraction patterns

A method is introduced to determine lattice parameters using machine learning. Analysis is presented of the impact of experimental conditions on machine learning prediction, and possibilities for automated unit-cell solution are explored.

X-ray powder diffraction in education. Part I. Bragg peak profiles

Peak profile functions in powder diffraction are presented with the support of Mathematica scripts, easily usable by interested readers, to explore the effect of different instrumental and microstructural parameters. Subsequent articles will illustrate the most common aberrations to the measured patterns and then total scattering methods.

Small-angle scattering for beginners

A non-technical yet rigorous introduction to small-angle scattering is proposed, through the systematic use of Fresnel–Feynman analysis of interference phenomena.

A remark on ab initio indexing of electron backscatter diffraction patterns

It is pointed out that ab initio indexing of electron backscatter diffraction (EBSD) patterns belongs to the field of indexing single-crystal diffraction data, and the problem can be solved on the same principles as indexing of patterns of other types. It is shown that EBSD-based data can be indexed by programs designed for X-ray data.

The ISOTILT software for discovering cooperative rigid-unit rotations in networks of interconnected rigid units

ISOTILT is a user-friendly web-based software package for discovering the cooperative rigid-unit modes in materials whose structures contain interconnected networks of rigid units.

anaklasis: a compact software package for model-based analysis of specular neutron and X-ray reflectometry data sets

A new software package (anaklasis) for model-based analysis of specular neutron and X-ray reflectivity is introduced. Key features include a user-friendly compact interfacial model definition scheme and a complete set of methods for co-refining data and estimating parameter uncertainty.

rmc-discord: reverse Monte Carlo refinement of diffuse scattering and correlated disorder from single crystals

A user-friendly Python-based program has been developed to analyze diffuse scattering from single crystals with the reverse Monte Carlo method. The approach allows for refinement of correlated disorder from atomistic supercells with magnetic or structural (occupational and/or displacive) disorder.

pyRS: a user-friendly package for the reduction and analysis of neutron diffraction data measured at the High Intensity Diffractometer for Residual Stress Analysis

This article is an overview of the pyRS software package, used for the reduction and analysis of data measured at the residual stress mapping instrument at Oak Ridge National Laboratory's High Flux Isotope Reactor.

propSym: a tool to establish relationships between property constants for material property tensors of any order

A MATLAB script is offered for the reduction of general higher-rank tensors in terms of independent components.

Growing a thriving international community for small-angle scattering through collaboration. Corrigendum

Errors in the article by Jill Trewhella [J. Appl. Cryst. (2021), 54, 1029–1033] are corrected.