The hydration of alite: a time-resolved qu­antitative X-ray diffraction approach using the G-factor method compared with heat release

The hydration of alite is examined from a crystallographic point of view. Rietveld analysis of water/alite pastes was carried out, combined with external-standard quantification, and the measured and calculated heat of hydration results are compared.

Qu­antitative X-ray diffraction phase analysis of poorly ordered nontronite clay in nickel laterites

Modified partial or no known crystal structure models have been developed to quantify turbostratically disordered nontronite in laterite ores.

Particle statistics of a capillary specimen in synchrotron powder diffractometry

Particle statistics in synchrotron powder diffractometry measured in a capillary transmission mode have been theoretically and experimentally investigated. It is shown that the size distribution of crystallites of about several micrometres can be evaluated by applying a spinner-scan method.

Application of a theory for particle statistics to structure refinement from powder diffraction data

A new methodology is proposed for structure refinement using powder diffraction data, from which models for particle statistics and any other statistical errors can formally be optimized. Structure parameters optimized by the method tend to become closer to those obtained by a single-crystal method as compared with results from the Rietveld method.

Hydroxylapatite lattice preferred orientation in bone: a study of macaque, human and bovine samples

The texture (lattice preferred orientation) of the crystallites in cortical bone samples has been studied by means of synchrotron hard X-ray diffraction, performing a combined analysis with the Rietveld method to quantify fully the preferred orientation features and to obtain lattice and microstructural parameters (such as crystallite size) simultaneously.

In situ observation of morphological changes of γ′ precipitates in a pre-deformed single-crystal Ni-base superalloy

The evolution of γ′ morphology in SCA425 Ni-base superalloy, pre-deformed in compression, was examined by in situ small-angle neutron scattering at high temperatures. Only severe pre-straining (2%) performed at elevated temperatures causes rafting during the subsequent heating.

Powder diffraction line profiles from the size and shape of nanocrystallites

A numerical procedure to carry out the integral on the powder diffraction sphere in reciprocal space and obtain accurate powder diffraction peak profiles for small crystallites is presented.

Characterization of the time-dependent L-asparagine monohydrate crystal phase transition

Rietveld refinement of X-ray diffraction data and dilatometry performed as a function of annealing time for L-asparagine monohydrate confirmed that the phase transition associated with loss of the water molecule (anhydrous phase) is time dependent.

Comparison of dynamical theory and phase-object approximation for neutron scattering from periodic structures

Two alternative theories that describe neutron scattering from periodic nanostructures are compared with each other and with experimental data. Dynamical scattering theory agrees with experiment for all scattering geometries, while the simpler phase-object approximation can only be used reliably under certain conditions.

Neutron time-of-flight diffraction used to study aged duplex stainless steel at small and large deformation until sample fracture

In situ neutron diffraction during tensile tests and elastoplastic self-consistent modelling were used to study elastoplastic deformation of both phases in duplex stainless steel. By using an original calibration of diffraction data, the range of the study was extended to large sample deformation, and mechanical effects attributed to damage processes initiated in ferrite were observed.

Determining the C60 molecular arrangement in thin films by means of X-ray diffraction

It is shown how atomic structural information can be obtained from molecular films without further knowledge of the single-crystal structure. C60 fullerene was chosen as a representative test material.

Influence of annealing on structure and optical properties of Mn-substituted ZnO nanoparticles

The influence of annealing on crystal growth and the micro- and mesoscopic structures of Mn-substituted nanocrystalline zinc oxide have been investigated using X-ray diffraction, high-resolution transmission electron microscopy and small-angle neutron scattering. Attempts have also been made to establish a structure–property correlation by showing the variation of optical band gap estimated from UV–visible absorption spectra with particle size.

Thermoelastic properties and crystal structure of CaPtO₃ post-perovskite from 0 to 9 GPa and from 2 to 973 K

The thermoelastic properties and crystal structure of post-perovskite-structured CaPtO₃ have been determined at pressures up to 9.3 GPa (at room temperature) and at temperatures between 2 and 869 K (at atmospheric pressure) by neutron powder diffraction. The behaviour of the cell parameters and crystal structure on compression and on thermal expansion are compared with those observed in the post-perovskite phases of MgSiO₃ and CaIrO₃.

CRYSTALS enhancements: absolute structure determination

Absolute structure determination features available in the crystallographic refinement program CRYSTALS are documented along with the some analysis of results obtained.

Using phases retrieved from two-dimensional projections to facilitate structure solution from X-ray powder diffraction data

Application of a charge-flipping algorithm to two-dimensional subsets of reflection intensities derived from powder diffraction data produces phases as reliable as those obtained from high-resolution transmission electron microscopy images. These can then be used to facilitate the solution of the crystal structures of polycrystalline materials.

Modification of preferred martensitic variant distribution by high magnetic field annealing in an Ni–Mn–Ga alloy

Modification of the preferred martensitic variant distribution by introducing a high magnetic field during the annealing process of the Ni₅₃Mn₂₅Ga₂₂ ferromagnetic shape memory alloy was investigated. It is revealed that high magnetic field annealing enhances the regular arrangement of the martensitic variants from the morphological point of view and effectively modifies the preferred orientation distribution of martensitic variants without changing the misorientation between them from the crystallographic point of view.

Validation of Bragg edge experiments by Monte Carlo simulations for qu­antitative texture analysis

An alternative wavelength-dispersive neutron transmission technique is applied on different instruments to investigate crystallographic preferred orientations. The validity of the results is supported by both conventional diffraction measurements and Monte Carlo simulations.

Reducing the background from pressure vessels using a BRIM

High-energy X-ray powder diffraction data, suitable for Rietveld analysis, were collected from samples in a high-pressure sample environment using a highly attenuating collimator and beam-stop assembly (background-reducing internal mask, BRIM) placed within the pressure vessel, around the sample, to block Bragg scattering from the upstream vessel wall and prevent the beam from hitting the downstream wall.

The effect of Cr³⁺ doping on the crystalline perfection and optical properties of zinc tris­(thiourea)sulfate, a nonlinear optical material

A study of the effect of Cr³⁺ doping in zinc tris(thiourea)sulfate (ZTS) crystals on crystalline perfection was carried out by high-resolution X-ray diffractometry. The formation of vacancies was revealed, and this was confirmed by photoluminescence studies. The optical band gap and linear refractive index of ZTS were found to increase as a result of doping.

Qu­antitative neutron diffraction texture measurement applied to α-phase alumina and Ti₃AlC₂

Quantitative texture measurements were made on differently prepared α-alumina and Ti₃AlC₂ ceramics using a neutron diffraction area detector and an improved data-reduction algorithm. The measured textures were used to extract one-dimensional pole densities, useful in the computation of diffraction elastic constants from single-crystal constants, and these were compared with the March and Rietveld functions widely used in powder diffraction.

Combined synchrotron X-ray and image-correlation analyses of biaxially deformed W/Cu nano­composite thin films on Kapton

A new method of combined synchrotron X-ray diffraction and digital image correlation techniques has been successfully applied for accurate strain measurements of nanocomposite thin films on Kapton during biaxial tensile tests.

Electrical and structural characterization of (K_xNa_1−x)NbO₃ ceramics modified with Li and Ta

An investigation of the effect of Li⁺ and Ta⁵⁺ on the crystal structure and electrical properties of (K_xNa_1−x)NbO₃ ceramics shows that the presence of Li⁺ suppresses the orthorhombic–rhombohedral phase transition at low temperatures. Phase coexistence over a wide temperature range may help to explain why the piezoelectric properties are enhanced in doped (K_xNa_1−x)NbO₃ ceramics compared to the undoped samples.

Automated microfluidic sample-preparation platform for high-throughput structural investigation of proteins by small-angle X-ray scattering

A fully automated microfluidic sample-preparation system for protein structure analysis is presented, characterized and used to screen the structural space of an adaptor protein, identifying a reversible oligomerization relevant for the understanding of cell signalling.

Electro-optic and electro-gyration effects on light propagation in 2m point-group crystals

An analytical description is presented of the generalized optical response for non-absorbing crystals of point-group symmetry under the influence of an externally applied electric field. Configurations of light propagation and applied electric field directions that try to decouple the contribution of the observed effects are identified.

Hard X-ray diffraction scanning tomography with sub-micrometre spatial resolution: application to an annealed γ-U_0.85Mo_0.15 particle

A UMoAl multi-phase particle has been investigated by scanning X-ray diffraction computed tomography, revealing a micrometre-scale layered embedded structure morphology that is accessible neither via classical two-dimensional X-ray diffraction mapping nor by electron microscopy.

First data acquired on the extended Q-range small-angle neutron scattering (EQ-SANS) diffractometer at the Spallation Neutron Source

The EQ-SANS instrument has completed its construction and commission and is ready to serve users. Initial experiments show that the instrument has met its design goals.

Accessing the hidden lamellar nanostructure of semi-crystalline nascent polymers by small-angle X-ray scattering contrast variation

The small-angle X-ray scattering contrast variation technique is able to suppress the air/grain interface scattering and highlights the contribution from the internal polymeric lamella.

The effect of gravity on the resolution of small-angle neutron diffraction peaks

Taking gravity into account, the major axes of resolution ellipses for neutron diffraction peaks at small scattering vectors all point to a position vertically above the incident beam center on the detector.

CrysPage: a program for displaying images of crystallization trials, rapid comparisons and analysis

A program has been written to display photographic images from 16 96-well plates obtained from high-throughput crystallization trials. Potential hits can be sorted and inspected according the chemical composition of their precipitant.

EDIFF: a program for automated unit-cell determination and indexing of electron diffraction data

EDIFF is a software suite for unit-cell determination of three-dimensional nanocrystals from randomly oriented electron diffraction patterns. It also fits and indexes the diffraction patterns.

Supercritical carbon dioxide behaviour in porous silica aerogel. Erratum

Errors in the paper by Ciccariello, Melnichenko & He [J. Appl. Cryst. (2011), 44, 43–51] are corrected.

Forthcoming meetings and short courses