Unveiling the anisotropic fractal magnetic domain structure in bulk crystals of antiskyrmion host (Fe,Ni,Pd)₃P by small-angle neutron scattering

The anisotropic fractal magnetic domain structure in bulk single-crystal (Fe_0.63Ni_0.30Pd_0.07)₃P has been quantitatively characterized using small-angle neutron scattering.

Modeling the partitioning of amphiphilic molecules and co-solvents in biomembranes

Partitioning of small amphiphilic molecules into biomembranes and other lamellar structures induces structural changes and impacts the properties of the membrane. This work presents a model to describe the amount of co-solvent within the bilayer, its localization and the induced changes to the bilayer structure. The implementation of this model is shared as a fitting algorithm within SasView.

Electron diffraction characterization of nanocrystalline materials using a Rietveld-based approach. Part II. Application to microstructural analysis

Quantitative microstructural characterization of different nanocrystalline materials based on Rietveld refinement of electron diffraction patterns is presented to demonstrate the application of the methodology described in Part I [Sinha et al. (2022). J. Appl. Cryst. 55, 953–965].

Extending MIEZE spectroscopy towards thermal wavelengths

A modulation of intensity with zero effort (MIEZE) setup is proposed for high-resolution neutron spectroscopy at momentum transfers up to 3 Å⁻¹, energy transfers up to 20 meV and an energy resolution in the microelectronvolt range using both thermal and cold neutrons.

Qu­antitative texture analysis at the WAND² and HIDRA diffractometers

Crystallographic texture measurement strategies have been developed and tested at two recently upgraded beamlines at the High Flux Isotope Reactor, Oak Ridge National Laboratory: WAND² and HIDRA.

Stabilizing ferroelectricity in alkaline-earth-metal-based perovskites (ABO₃) via A- (Ca²⁺/Sr²⁺/Ba²⁺) and B-site (Ti⁴⁺) cationic radius ratio (R_A/R_B)

This study establishes the structure–property correlation that eases the initial optimization process for various alkaline-earth-metal-based perovskites.

Investigation of physical properties of Si crystallites in W/Si multilayers

The nature of the observed bulk inhomogeneities in the silicon layers in W/Si multilayers is established. In the diffuse scattering spectra, specific substructures, which are clearly resonant in nature, are observed. The physical nature of some of them is not established.

Insights into the structural symmetry of YCrO₃ from synchrotron X-ray diffraction

A high-resolution synchrotron X-ray diffraction study of a YCrO₃ single crystal has allowed the structural parameters of the noncentrosymmetric P12₁1 space group to be obtained. The pathway of spin interactions was found for the formation of antiferromagnetism in YCrO₃. Ferroelectricity in YCrO₃ may originate from the strain-balanced Cr1—O3(O4) and Cr2—O5(O6) bonds and the local distortion modes of CrO₆ octahedra in the P12₁1 space group. The relationship between microscopic and macroscopic properties has been revealed.

Magnetic neutron scattering from spherical nanoparticles with Néel surface anisotropy: analytical treatment

The magnetization profile and the ensuing magnetic neutron scattering signal from an inhomogeneously magnetized spherical nanoparticle with Néel surface anisotropy are derived analytically.

Magnetic neutron scattering from spherical nanoparticles with Néel surface anisotropy: atomistic simulations

Based on the Landau–Lifshitz equation, atomistic simulations of the magnetic neutron scattering from inhomogeneously magnetized spherical nanoparticles with a strong surface anisotropy are carried out.

Three-dimensional model of a split-crystal X-ray and neutron interferometer

The observation of neutron interference using a split-crystal interferometer opens the way to realizing interferometers with vast arm separation and length. Setting the design specifications requires a three-dimensional model of their operation. Also, the spatial coherence of the source affects the interference visibility. This paper presents a novel formalism to model crystal interferometers, operating with both coherent and partially coherent X-rays and neutrons, in three dimensions.

Efficient data reduction for time-of-flight neutron scattering experiments on single crystals

In neutron scattering experiments, data sets with different statistical significance are collected. A new method is presented to efficiently calculate the weights of single-crystal time-of-flight measurements, and to add together the various contributions.

Progressive alignment of crystals: reproducible and efficient assessment of crystal structure similarity

Evaluating crystal structure packings using coordinate root-mean-square deviation (RMSD) for N molecules (or N asymmetric units) in a reproducible manner requires metrics to describe the shape of the compared molecular clusters to account for alternative approaches used to prioritize selection of molecules. Described here is a fast algorithm called Progressive Alignment of Crystals (PAC) to evaluate crystal packing similarity using coordinate RMSD and introducing the radius of gyration as a metric to quantify the shape of the superimposed clusters.

Band-gap assessment from X-ray powder diffraction using artificial intelligence

The band gaps of metal–organic framework, organic and inorganic materials were assessed from X-ray powder diffraction patterns. The assessments were done with convolutional neural networks.

Automatic bad-pixel mask maker for X-ray pixel detectors with application to serial crystallography

Attention is focused on perhaps the biggest bottleneck in data analysis for serial crystallography at X-ray free-electron lasers, which has not received serious enough examination to date. An effective and reliable way is presented to identify anomalies in detectors, using machine learning and recently developed mathematical methods in the field referred to as `robust statistics'.

Small-angle X-ray microdiffraction from fibrils embedded in tissue thin sections

The availability of micro- and nano-X-ray beams makes measurement of scattering from very small volumes possible, opening possibilities for deriving in situ structural information on fibrillar constituents in complex materials and tissues. This work outlines a set of strategies for confronting major technical obstacles to extract useful structural information from scattering derived from these samples.

Preparation of pyrite concentrate powder from the Thackaringa mine for qu­antitative phase analysis using X-ray diffraction

A method for performing accurate quantitative phase analysis using X-ray powder diffraction of pyrite concentrate mineral samples from the Thackaringa mine has been devised. The sample preparation optimization process is described. Grain size reduction suitable for analysis by the Rietveld method was achieved using ball milling.

Improving data quality for three-dimensional electron diffraction by a post-column energy filter and a new crystal tracking method

Zero-loss energy-filtered 3D electron diffraction experiments are performed using a post-column energy filter, and both data quality and structures are improved after energy filtration. A novel crystal tracking method is developed, based on a live high-angle annular dark-field image stream. This method can track crystals to achieve high-completeness data sets without adding any additional dose or removing any frames.

A reverse Monte Carlo algorithm to simulate two-dimensional small-angle scattering intensities

Small-angle neutron scattering and small-angle X-ray scattering are important experimental techniques for studying the behaviour and properties of materials on the nanoscale. This article describes a numerical algorithm that uses reverse Monte Carlo simulations to model scattering intensities observed on a two-dimensional small-angle scattering detector.

Optimization strategies and artifacts of time-involved small-angle neutron scattering experiments

This article reviews the opportunities and limitations of time-involved small-angle neutron scattering experiments, with the typical artifacts of the recorded data illustrated by virtue of the response of the skyrmion lattice in MnSi under periodic changes of the direction of the stabilizing field.

Shape-induced superstructure formation in concentrated ferrofluids under applied magnetic fields

In-field small-angle neutron scattering reveals superstructure formation in a concentrated dispersion of spherical and cuboidal iron oxide nanoparticles.

Multiscale magnetization in cobalt-doped ferrite nanocubes

This article presents a set of cuboidal cobalt ferrite nanoparticles with exceptionally high crystallinity, revealed by homogeneous magnetization with negligible near-surface spin disorder as observed by magnetic small-angle neutron scattering.

Pressure cells for in situ neutron total scattering: time and real-space resolution during deuterium absorption

In situ gas-loading sample holders for two-dimensionally arranged detectors in time-of-flight neutron total scattering experiments have been developed for the structural analysis of the deuterium absorption process using time and real-space resolution.

OPUS: an easy way to push the limits of SANS instruments towards USANS

There is a rapidly growing trend in the application of ultra-small-angle neutron scattering (USANS) across many different fields of research, as a stand-alone technique and in combination with small-angle neutron scattering (SANS). Implementation of USANS capability on pin-hole SANS instruments was investigated using neutron ray-tracing simulations, and the design and optimization of the USANS optics are presented.

Reconstruction algorithms for grain mapping by laboratory X-ray diffraction contrast tomography

Grain reconstruction methods based on both forward and back calculations have been developed for laboratory-based diffraction contrast tomography. These methods are computationally efficient and can give good orientation and spatial accuracies, and the code is open source.

Stochastic atomic modeling and optimization with fullrmc

fullrmc is an open-source framework to model and optimize atomic and molecular materials. It is enabled with reinforcement machine learning and designed to solve complex crystalline, amorphous atomic or molecular structures up to the nanoscopic scale.

Updates in SASfit for fitting analytical expressions and numerical models to small-angle scattering patterns

Recent enhancements and additions to the SASfit program are discussed, including anisotropic scattering models, flexible distributions, regularization techniques such as the expectation-maximization method, and new structure factors, especially for ordered nano- and meso-scaled material. The Ornstein–Zernike solver for numerical structure factors is also introduced.

Euphonic: inelastic neutron scattering simulations from force constants and visualization tools for phonon properties

An overview of the Euphonic Python package for efficient simulation of inelastic neutron scattering by phonons from force constants is presented.

The Knowledge Machine: How an Unreasonable Idea Created Modern Science