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

This commentary describes the growth of small-angle scattering as a technique for structural characterization in noncrystalline systems across chemistry, biology and materials and how the international community continues to grow and prosper through highly successful international meetings and a strategic collaborative relationship with the International Union of Crystallography.

A capillary-based microfluidic device enables primary high-throughput room-temperature crystallographic screening

A novel capillary-based microfluidic strategy to accelerate the process of small-molecule-compound screening by room-temperature X-ray crystallography using protein crystals is reported.

Simulating and benchmarking neutron total scattering instrumentation from inception of events to reduced and fitted data

A method of simulating and benchmarking neutron time-of-flight instrumentation from inception of events at the moderator surface to fully reduced and fitted data is presented. The case of the DISCOVER beamline concept and its future place within the Spallation Neutron Source's time-of-flight diffraction suite is used as an example.

Intragranular strain estimation in far-field scanning X-ray diffraction using a Gaussian process

A novel regression method for estimating intragranular strain in polycrystalline materials from three-dimensional X-ray diffraction data is presented and evaluated. The method incorporates an equilibrium constraint to the reconstructed strain field by using a Gaussian process.

X-ray rocking curve imaging on large arrays of extremely tall SiGe microcrystals epitaxial on Si

The rocking curve imaging technique was realized with a two-dimensional X-ray detector and laboratory-sealed X-ray tube in order to map the local crystal lattice bending inside arrays of extremely tall epitaxial SiGe microcrystals grown on patterned Si substrates. The domains formed by cracks were imaged in a highly asymmetric diffraction setup.

Stable sample delivery in a viscous medium via a polyimide-based single-channel microfluidic chip for serial crystallography

A sample-delivery method for serial crystallography is introduced, which uses a polyimide-based single-channel microfluidic chip and a viscous medium.

Combining a multi-analyzer stage with a two-dimensional detector for high-resolution powder X-ray diffraction: correcting the angular scale

The correction of the angular scale of powder diffraction data resolved axially by a two-dimensional pixel detector after an analyzer crystal or multi-analyzer stage is discussed. Angular correction reduces peak asymmetry at low angles and can be combined with a scheme that varies axial acceptance with angle to optimize angular resolution or statistical quality as required.

Determining the maximum information gain and optimizing experimental design in neutron reflectometry using the Fisher information

A framework is developed using the Fisher information for information quantification in neutron reflectometry. The framework's utility is demonstrated in the rapid estimation of model parameter uncertainties, as well as in experimental design to maximize information gain about given systems.

Morphology control of laser-induced dandelion-like crystals of sodium acetate through the addition of acidic polymers

Crystal growth speeds, crystal sizes and the morphology of sodium acetate (CH₃CHOONa) crystals in the presence of polymaleic acid and polyacrylic acid with different concentrations were investigated in supersaturated solutions of sodium acetate.

Formation and characterization of an Al-rich metastable phase in the Al–B phase diagram

A new metastable Al-rich phase (chemical formula Al_1.28B) stable up to 630°C is synthesized by vacuum heating of mechanically alloyed Al and B powders. Its structure is solved from X-ray powder diffraction.

Characterization of the CaCO₃ calcination process by the Porod invariant behaviour

The chemical structures of the phases of CaCO₃ samples undergoing a calcination process, as well as the volume fractions and matter densities of those phases, are determined by the Porod invariant behaviour.

Qu­antitative powder diffraction using a (2 + 3) surface diffractometer and an area detector

Conversion of 2D detector images measured on a (2 + 3) surface diffractometer to meaningful intensities that can be used for quantitative analysis of powdered and textured materials is discussed.

In-plane crystalline anisotropy of bulk β-Ga₂O₃

A new anisotropy characteristic of bulk (201) β-Ga₂O₃ is presented. The broadening of symmetric rocking curves indicates `twofold' anisotropy with a maximum along the [102] direction. Williamson–Hall analysis reveals that this is induced by anisotropy in the length over which the crystal structure is not disrupted by grain boundaries or stacking faults, which we term `lateral limited size'. The lateral limited size is governed by {200} stacking faults along the [102] direction and grain boundaries along the [010] direction.

Qu­antitative phase analysis of Bi₂Sr₂CaCu₂O_8+x and competing intergrowth and co-crystallizing phases via a Rietveld refinement study

Quantitative phase analysis is undertaken of the intergrowth and co-crystallizing phases that grow in the high-temperature superconductor Bi₂Sr₂CaCu₂O_8+x, via a Rietveld refinement study that incorporates effects such as preferred orientation, modulation and microabsorption.

Spatial correlation of embedded nanowires probed by X-ray off-Bragg scattering of the host matrix

The spatial correlation of vertically aligned Ni and CoNi alloy nanowires in an SrTiO₃ matrix has been analysed through the scattering around the Bragg reflections of the host matrix. The study demonstrates that off-Bragg scattering can be used in a selective and nondestructive way to study nano-objects inside a crystalline layer in nanocomposites and stacked nanostructures.

GPU-accelerated multitiered iterative phasing algorithm for fluctuation X-ray scattering

The paper presents efforts to accelerate the multitiered iterative phasing (MTIP) algorithm on contemporary graphics processing units (GPUs). Application portability is demonstrated by accelerating the MTIP algorithm on NVIDIA and AMD GPUs using a single codebase.

Operando structural investigations of thermoelectric materials

An X-ray scattering study of thermoelectric materials in operando conditions is reported.

Novel study on the electron density distribution projection maps calculated via the discrete cosine transform

The discrete cosine transform can be used to determine the real crystal structure from an appropriate mirror-symmetric electron density distribution projection map.

Long- and short-range order in the Ni₅₂Co₂Fe₂₀Ga₂₆ ferromagnetic Heusler alloy

EXAFS could not convincingly distinguish between the L2₁ and B2 austenitic phases of Ni₅₂Co₂Fe₂₀Ga₂₆, but has reliably fitted the modulated martensite by a non-modulated L1₀ structure. XANES found a redistribution of the empty p states at the martensitic transformation.

Separation of the inelastic and elastic scattering in time-of-flight mode on the pinhole small-angle neutron scattering diffractometer K­WS-2

A new chopper has been installed at the sample position in front of the sample stage at the KWS-2 small-angle neutron-scattering diffractometer of the Jülich Centre for Neutron Science. The pulsed beam and the time-of-flight data acquisition enable the separation of elastic and inelastic scattering from hydrogenous samples.

Dislocation contrast on X-ray topographs under weak diffraction conditions

The contrast of dislocations in 4H-SiC crystals shows distinctive features on grazing-incidence X-ray topographs for diffraction at different positions on the operative rocking curve. A misorientation model together with a ray-tracing simulation effectively interpret the features on X-ray topographs under weak diffraction conditions.

Refinements on electron diffraction data of β-glycine in MoPro: a quest for an improved structure model

Refinement of a small-molecule crystal structure against electron diffraction data is now available in the MoPro software with the implementation of electron scattering factors, using a spherical or multipolar atom model.

X-Light: an open-source software written in Python to determine the residual stress by X-ray diffraction

Software for residual stress determination by X-ray diffraction is introduced.

PyQCstrc.ico: a computing package for structural modelling of icosahedral quasicrystals

PyQCstrc.ico is a computer package for building a 6D structure model of icosahedral quasicrystals with the Python3 programming language.

GIDInd: an automated indexing software for grazing-incidence X-ray diffraction data

The GIDInd software package is a MATLAB-based application for automated indexing of grazing-incidence X-ray diffraction data.

A simple gas introduction system for cryogenic powder X-ray diffraction

A simple system is described for the introduction and deposition of volatiles into standard X-ray diffraction capillaries while they are mounted in situ in the X-ray beam for X-ray diffraction analyses.

N₂–O₂ icing in single-crystal in-house X-ray diffraction experiments using an open-flow helium cryostat

The condensation of an oxygen–nitro­gen `ice' on a single crystal studied using in-house diffraction experiments with an open-flow helium cryostat is discussed in relation to data quality and temperature estimation.

Physics of Electrons in Solids

The Beauty of Chemistry: Art, Wonder, and Science