Accuracy in Rietveld qu­antitative phase analysis: a comparative study of strictly monochromatic Mo and Cu radiations

This work focuses on the comparison of Mo Kα₁ and Cu Kα₁ radiations for the Rietveld quantitative phase analysis of challenging crystalline mixtures including amorphous content determination. The quantifications have been carried out by using calibration curves with increasing amounts of a given phase. Mo Kα₁ patterns were found to yield slightly more accurate analyses than those derived from Cu Kα₁ radiation.

Neutron imaging using a conventional small-angle neutron scattering instrument

This article demonstrates how neutron imaging can be performed using a conventional small-angle neutron scattering instrument.

In situ diagnostics of the crystal-growth process through neutron imaging: application to scintillators

The unique possibilities enabled by neutron imaging for in situ remote diagnostics of microstructural characteristics during crystal growth are demonstrated, even when the materials and surrounding structures are opaque to other more conventional interrogation techniques. Neutron radiography is implemented to image remotely the uniformity of elemental distribution (e.g. dopant concentration) during crystal growth, the location of the liquid/solid interface and the presence of macroscopic crystal defects (e.g. cracks), all with a temporal resolution of 5–7 s.

NearTree, a data structure and a software toolkit for the nearest-neighbor problem

A convenient data structure for the nearest-neighbor problem is discussed.

Qu­antitative analysis of structural inhomogeneity in nanomaterials using transmission electron microscopy

This work suggests a method for quantifying inhomogeneity of crystal structure at the nanoscale using high-resolution transmission electron microscopy. The method can measure the lattice parameters with picometric accuracy and a spatial resolution of a few to tens of nanometres without requiring aberration correction or posing any strict requirements on the sample.

Structure of nanocrystalline calcium silicate hydrates: insights from X-ray diffraction, synchrotron X-ray absorption and nuclear magnetic resonance

The structure of nanocrystalline calcium silicates hydrates (C–S–H) having Ca/Si ratios ranging between 0.57 ± 0.05 and 1.47 ± 0.04 was studied. All samples are nanocrystalline and defective tobermorite. An increase of the Ca/Si ratio resulting from omission of bridging Si in the Si chains and incorporation of interlayer Ca was observed.

X-ray diffraction from nonuniformly stretched helical molecules

A theoretical formulation for the diffraction from nonuniformly strained helical molecular assemblies is presented. The predictions of this theory are discussed in the context of double-stranded DNA and actin filaments in the presence and absence of nonuniform strains.

Hybrid reciprocal lattice: application to layer stress determination in GaAlN/GaN(0001) systems with patterned substrates

A general high-accuracy method for detecting and distinguishing elastic and plastic relaxation in epitaxial layers grown on patterned substrates is applied to a Group III–nitride system. The method is based on X-ray multiple diffraction.

A crystallization apparatus for temperature-controlled flow-cell dialysis with real-time visualization

An apparatus for the optimization of crystal growth using precise temperature control and dialysis combined with real-time visualization has been developed.

Applications of Bayesian corrections for systematic errors in Rietveld refinements

This paper reports extensive testing of the Bayesian procedure for correction of systematic errors in Rietveld refinements. This testing has been performed using data collected for one sample using four X-ray and neutron diffractometers.

Characterization of the shape and line-edge roughness of polymer gratings with grazing incidence small-angle X-ray scattering and atomic force microscopy

This study presents a series of grazing-incidence small-angle X-ray scattering experiments on polymer line gratings, together with a quantitative analysis and comparison with the real-space structure probed by atomic force microscopy. The results provide a detailed characterization of the average profile and estimates of line-edge roughness.

Double Bragg scattering observed in small-angle X-ray scattering from highly oriented pyrolytic graphite

Two-dimensional small-angle X-ray scattering measurements were performed on highly oriented pyrolytic graphite. The observed radial streak patterns are discussed in the context of double Bragg scattering.

Diffuse X-ray scattering from 180° ferroelectric stripe domains: polarization-induced strain, period disorder and wall roughness

The nanostructure of 180° ferroelectric stripe domains is analysed by diffuse X-ray scattering. The domain period, period disorder, polarization-induced strain and wall roughness are quantitatively determined.

Estimation of the density distribution from small-angle scattering data

The density distribution is estimated from small-angle scattering data from symmetrical objects without using the distance distribution function as an explicit intermediate.

A monoclinic to tetragonal crossover in (Na_0.5Bi_0.5TiO₃)_(1−x)(BaZrO₃)_x ceramic: a lead-free ferroelectric material

A detailed structural investigation of (Na_0.5Bi_0.5TiO₃)_(1−x)(BaZrO₃)_x (x = 0.00, 0.01, 0.03, 0.05 and 0.07) was carried out as a function of composition using Rietveld analysis of powder X-ray diffraction data.

Film thermal stability correlation with seeding modes in the growth of YBa₂Cu₃O_7−δ crystals

Buried seeding is developed to strengthen the thermal stability of YBa₂Cu₃O_7−δ (YBCO) films, leading to an enhancement of endurable maximum processing temperature of over 30 K in low supersaturation. Furthermore, the buried-seeding mode was successfully applied in growing single crystals of other REBCO (RE = Nd, Sm, Gd) oxides.

Qu­antifying radiation damage in biomolecular small-angle X-ray scattering

A method for analyzing radiation damage experiments in biological small-angle X-ray scattering is presented. This method allows direct comparison between results obtained at different beamlines and by different experimenters.

Neutron diffraction study of (K_xNa_1−x)NbO₃-based ceramics from low to high temperatures

A low- to high-temperature neutron diffraction study of some (K_xNa_1−x)NbO₃-based ceramics has been carried out. The structure of these ceramic compositions has been determined using Rietveld refinement.

Retrieving the spatially resolved preferred orientation of embedded anisotropic particles by small-angle X-ray scattering tomography

By the combination of small-angle X-ray scattering with tomographic techniques, the spatially varying preferred orientation of micrometre-sized talc particles embedded in injection-moulded isotactic polypropylene has been retrieved nondestructively.

Disc-shaped nanocrystal model for simulating the diffraction peak profile from a one-dimensional superlattice and its application to Pt/AlN superlattice films

On the basis of the film structure of a Pt/AlN multilayer film which exhibits a superlattice peak after annealing, a disc-shaped nanocrystal model is proposed for simulating the diffraction profile from a one-dimensional superlattice, and the effects of the in-plane crystal size and the orientation distribution on the profile are discussed.

Probing structural chirality with high-energy synchrotron radiation

In spite of the low absolute values of the resonant contribution at high energy, accurate measurements of the Bragg intensities up to high Q values are capable of providing data sufficient for absolute structure determination.

Neutron and hard X-ray diffraction studies of the isothermal transformation kinetics in the research reactor fuel candidate U–8 wt%Mo

The nuclear fuel candidate U–8 wt%Mo has been investigated by means of neutron and hard X-ray diffraction, revealing the isothermal transformation kinetics of the high-temperature γ-UMo phase into its thermal equilibrium microstructures.

Ultra-small-angle neutron scattering with azimuthal asymmetry

A method is given for converting slit-smeared azimuthally asymmetric data collected on a double-crystal diffractometer for concatenation with the usual pinhole-geometry small-angle neuton scattering data.

Fast two-dimensional grid and transmission X-ray microscopy scanning methods for visualizing and characterizing protein crystals

This article reports the incorporation of a fast continuous grid scan with both still and oscillation images into the Swiss Light Source macromolecular crystallography beamlines and its application in visualization of protein crystals with scanning transmission X-ray microscopy.

Rapid automated superposition of shapes and macromolecular models using spherical harmonics

A method utilizing a spherical harmonics representation of the scattering amplitudes for a rapid superposition of three-dimensional models is developed.

Asymmetric skew X-ray diffraction at fixed incidence angle: application to semiconductor nano-objects

A solution for X-ray experiments in an asymmetric skew geometry with a constant angle of incidence is described. It enables mapping of the three-dimensional reciprocal space of a sample by a single motor scan.

Room-temperature macromolecular crystallography using a micro-patterned silicon chip with minimal background scattering

A micro-patterned sample holder of single-crystalline silicon, loaded with multiple protein crystals which are exposed to a humidified gas stream, allows high-quality room-temperature data collection.

Lattice bending in three-dimensional Ge microcrystals studied by X-ray nanodiffraction and modelling

The scanning X-ray nanodiffraction technique is used to map the lattice bending in heteroepitaxial Ge microcrystals grown on high aspect ratio Si pillars produced by thermal strain relaxation. The simulated three-dimensional reciprocal space maps based on finite element calculations are in a good agreement with the measured ones.

Compression deformation behavior of Zircaloy-4 alloy changing with activated twinning type at ambient temperature: experiment and modeling

The plastic deformation modes and stress/strain partitioning between parent and child grains resulting from different types of twinning are discussed. Insight into the effect of deformation twinning on the plastic deformation behavior of Zr-4 alloy is provided.

Nanoscale order in the frustrated mixed conductor La_5.6WO_12−δ

A combination of neutron and X-ray diffraction together with pair distribution function and EXAFS analysis is shown to solve the crystal structure for the highly disordered proton and electron conductor La_5.6WO_12−δ on average and local length scales.

Martensite adaption through epitaxial nano transition layers in TiNiCu shape memory alloys

The crystallographic origin of ultralow superelastic fatigue in NiTi-based shape memory alloys is explored. Ti-rich precipitates are coupled to austenite and martensite, and serve as epitaxial seeds during the repeated phase transformations.

Modelling of cation displacements in SrTiO₃ by means of multi-energy anomalous X-ray diffuse scattering

The X-ray diffuse scattering pattern of SrTiO₃ has been measured and simulated. It is shown that the structural model based on the displacement of the Sr²⁺ and Ti⁴⁺ cations is ambiguous, whereas the method of multi-energy anomalous diffuse scattering yields an unambiguous solution.

Identification of rogue datasets in serial crystallography

In serial crystallography, CC_1/2 may be used as an optimization target, and outlier datasets can be identified on the basis of their influence on the average CC_1/2 of the merged data. This leads to the ΔCC_1/2 method presented here.

Modeling truncated pixel values of faint reflections in MicroED images

A procedure is presented to model the truncated low pixel counts in micro-electron diffraction (MicroED) images. The correction could extend to any conventional macromolecular X-ray crystallography or X-ray free-electron laser measurements.

Data processing pipeline for serial femtosecond crystallography at SACLA

A data processing pipeline for SACLA was developed, based on Cheetah and CrystFEL. Real-time analysis and rapid structure solution were enabled.

Hummingbird: monitoring and analyzing flash X-ray imaging experiments in real time

Hummingbird is an open-source scalable Python-based software tool for real-time analysis of diffraction data with the purpose of giving users immediate feedback during their experiments.

XMDYN and XATOM: versatile simulation tools for qu­antitative modeling of X-ray free-electron laser induced dynamics of matter

Hard X-ray induced dynamics of matter can be simulated with the computational tools XMDYN and XATOM.

IOTA: integration optimization, triage and analysis tool for the processing of XFEL diffraction images

An integration optimization, triage and analysis tool (IOTA) is presented, which uses a grid-search approach to maximize the success of indexing and integrating serial X-ray free-electron laser diffraction images. IOTA also includes several useful tools for on-site diffraction data processing.

On the release of cppxfel for processing X-ray free-electron laser images

Here cppxfel, a software package for integration and post-refinement of serial femtosecond crystallography data, is released.

OnDA: online data analysis and feedback for serial X-ray imaging

This article describes the software package OnDA: online data analysis and feedback for serial X-ray imaging.

DCC: a Swiss army knife for structure factor analysis and validation

DCC is a wrapper for third-party software packages to aid in structure factor analysis and validation. As the results are recorded in PDBx/mmCIF format, the output from DCC can be used in automatic data pipelines.

XDSAPP2.0

A new version of XDSAPP, an expert system and graphical user interface for the automated processing of diffraction images using XDS, is presented.

NIMS: a database on nucleobase compounds and their interactions in macromolecular structures

This article describes an online database on the interactions of nucleobase compounds in macromolecular structures.

PTCLab: free and open-source software for calculating phase transformation crystallography

This article introduces a free and open-source program, PTCLab, for calculating phase transformation crystallography.

SUNBIM: a package for X-ray imaging of nano- and biomaterials using SAXS, WAXS, GISAXS and GIWAXS techniques

The program SUNBIM, here presented, is a novel suite of programs designed for scientists who make use of small- and wide-angle X-ray scattering (SAXS/WAXS) and grazing-incidence SAXS/WAXS (GISAXS/GIWAXS) techniques for the structural characterization of artificial or natural materials. It consists of four sections: (1) Calibration; (2) Batch Script & 2D Mesh Composite; (3) multi-scan SAXS and WAXS data analysis (M-SAWANA); (4) single-scan SAXS and WAXS data analysis (S-SAWANA).

Silver Nanoparticles. From Silver Halide Photography to Plasmonics. By Tadaaki Tani. Oxford University Press, 2015. Pp. 224. Price (hardcover) GBP 65.00. ISBN 978-0-19-871460-6