Having synthesised an AlON-bonded ceramic corundum material, Al5O3N3 (15R) polytype coexisting with α-Al2O3 was identified. The sample was prepared from an alumina-rich mixture of Al2O3 and AlN substrates and fired at 1650 °C in a nitrogen atmosphere. Using the X-ray external standard quantitative method, one of the reaction products, α-Al2O3, was quantified. From the remaining substrates the stoichiometric composition of the second phase was calculated. The applied method of crystal structure determination consisted of three stages. In the first stage, the Le Bail method of X-ray pattern decomposition was used for the extraction of Al5O3N3 (15R) diffraction lines from a two-phase diffractogram. The space group and unit-cell dimensions from the isostructural SiAl4O2N4 SiAlON phase, producing the same X-ray pattern, were used as input data. Next, the direct structure determination in real space was applied for initial structural model derivation, which was followed by Rietveld refinement. The solved crystal structure of Al5O3N3 (15R), except the stacking sequence, proved to be closely related to the structure of Al7O3N5 (21R) polytype. The Al5O3N3 (15R) is trigonal with space group R-3m, unit-cell dimensions a0 = 3.0128 Å, c0 = 41.8544 Å, and volume V = 329.00 Å3. The model of Al5O3N3 (15R) polytype structure has positional disordering in one of three (6c) Al sites, which leads to stacking faults in six tetrahedral layers. Every third tetrahedron from LR3 and LR4, LR8 and LR9, LR13 and LR14 layers is rotated by 180°.

The crystal structure of paliperidone palmitate has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional techniques. Paliperidone palmitate crystallizes in space group P21/c (#14) with a = 34.415 40(35), b = 10.093 49(7), c = 10.904 92(9) Å, β = 94.3917(9)°, V = 3776.94(6) Å3, and Z = 4. The conformation of the paliperidone fragment differs from that of the parent compound. The palmitate chain exhibits a slight twist close to the ester group. Several C–H⋅⋅⋅O hydrogen bonds contribute to the crystal packing, which is dominated by van der Waals interactions. The powder pattern is included in the Powder Diffraction File™ as entry 00-066-1614.

One hundred years ago X-ray powder diffraction, one of the premier techniques used in the characterization of materials, was invented. Its origins can be traced to two landmark contributions presented to the scientific community in 1916. They are the better known and celebrated work carried out by Paul Scherrer under the guidance of Peter W. Debye, at the University of Göttingen, Germany, and the lesser known work of Albert W. Hull performed at the Research Laboratory of the General Electric Company, Schenectady, NY, USA. The great contributions of Scherrer and Debye have been prominently recognized. They are presented in many textbooks and in technical and scientific articles published in the area of characterization of materials using powder diffraction techniques. The camera designed by them, later called “the Debye–Scherrer camera”, was used extensively for many years and the experimental setup (“the Debye–Scherrer geometry”) is still used today. On the other hand, the work performed by Hull has not been adequately appreciated and remembered. In this communication, an account of his contributions to X-ray powder diffraction and to crystallography is presented at 100 years of his landmark publication, which appeared in the first issue of Physical Review of 1917.

In this work, the reduction mechanism of potassium chromate (K2CrO4) was investigated via in situ high-temperature X-ray diffraction coupled with Fourier transform infrared spectroscopy. During the hydrogen reduction of K2CrO4, the formation of K3CrO4, KCrO2, and KxCrO2 were detected for the first time. The study discovered that K2CrO4 was firstly reduced to K3CrO4 and an amorphous Cr(III) intermediate product at low temperature (400–500 °C). Moreover, the K3CrO4 was the only crystalline material at this stage. As the temperature increased, a stabilized amorphous CrOOH was formed. At a high temperature (550–700 °C), KCrO2 was generated. Interestingly, a portion of KCrO2 was spontaneously decomposed during the hydrogen reduction, accompanying by the formation of K0.7CrO2. Finally, the results clearly illustrated the reduction mechanism of K2CrO4: K2CrO4 → K3CrO4 → amorphous intermediate → KCrO2.

Knowledge of the surface composition of planetary bodies comes from a number of sources; such as landers, remote sensing and meteorites. However, the bulk mapping of the composition of planetary surfaces has been undertaken by analysis of reflected sunlight and these data—principally collected in the near-infra-red (IR) region—are notoriously broad and ambiguous. Hence, if laboratory spectra could be tied to physical properties measurements, such as diffraction, this would substantially aid our understanding of processes occurring in these extra-terrestrial environments. This contribution presents the capability of collecting near-IR data at the same time as neutron and synchrotron X-ray diffraction in a range of conditions (low temperature, vacuum, and humidity variations) and highlights two examples where this capability could enhance our understanding of planetary surfaces.

The grazing incidence diffraction (GID) method in side inclination mode, described by Ma et al. in 2002, of polycrystalline thin-film residual stress was revisited and explained using simple geometric relations. To overcome the issue of decreasing peak intensity of this method, which is induced by the decreasing incident angle because of the Eulerian cradle Chi-tilt, an improvement of Omega (ω)–Phi (φ) compensation was devised and applied to a NiFe thin-film sample. The geometry of this improved ω–φ compensated GID method in side inclination mode is detailed in this paper. This improvement guarantees a constant incident angle on the sample surface and a fixed sample illumination volume during measurement. The measured data were analysed using parametric refinement in DIFFRAC.TOPAS v6 software in Launch Mode, and details of the input file (.INP) are explained in this paper. The tensile stress of the NiFe thin-film sample was measured to be 1181 ± 85 MPa using this improved method.

We present a detailed description of the SESAME Materials Science (MS) beamline for X-ray diffraction (XRD) applications, presently under construction in Allan, Jordan. The beamline is based on components previously installed at the Swiss Light Source, but modifications in the beamline design have been introduced to match the characteristics of the SESAME storage ring. The SESAME MS beamline will accommodate XRD experiments in the energy range between 5 and 25 keV. The beamline ray tracing analysis at 10 keV estimates the flux at the sample to be of the order of 1013 (photons s−1), the energy resolution is about 2 eV and the effective beam size at the sample of 300 × 2800 µm2. Investigations of microstruture will be possible as the instrumental broadening, resulted from simulating the diffraction pattern for a standard material, is of the order of 0.01° at 15 keV. A wide range of applications will be possible at the beamline, such as powder diffraction studies, single crystals and in situ XRD. The commisioning of the beamline is expected to be in the second half of 2017.

The ICDD has implemented an option in Powder Diffraction File (PDF)-4 products to calculate time-of-flight (TOF) neutron powder diffraction patterns using atomic coordinates and structure information (the PDF-4+ 2016 has 271 499 entries that contain atomic coordinates and structure data). The calculated pattern data are used to populate PDF data cells and entries that contain d-spaces and neutron intensities, and are also available for calculated on-the-fly fully digitized patterns. To extend this on-the-fly capability, we include size and strain effects that affect the profile shapes. For specific application to TOF neutron diffraction full pattern analyses, a method was developed for calculating a background function. This method treats incoherent scattering and a zeroth order approximation to thermal diffuse scattering. The results are compared with experimental data from SRM 640C (Si), SRM 676 (Al2O3 corundum), SRM 660C (LaB6), and NAC (Na2La3Al2F14) instrument standards. Finally, a comparison of the calculated total patterns (Bragg scattering plus background) scattering contrast between Nd2Ni2InD7.52 and Nd2Ni2InH7.52 shows the value of neutron scattering simulation for planning experiments.

Representative compounds of the new family of magnetic materials Gd5−xNdxSi4 were analyzed by X-ray diffraction at the XRD1 beamline at Laboratório Nacional de Luz Síncrotron. To reduce X-ray absorption, thin layers of the powder samples were mounted outside the capillaries and measured in Debye–Scherrer geometry as usual. The XRD analyses and the magnetometry results indicate that the behavior of the magnetic transition temperature as a function of Nd content may be directly related to the average of the four smallest interatomic distances between different rare earth sites of the majority phase of each compound. The quality and consistency of the results show that the XRD1 beamline is able to perform satisfactory XRD experiments on high-absorption materials even off the best conditions.

Novel compounds Ca8−xPbxZnBi(VO4)7 (0 ≤ x ≤ 1.5) solid solution with the whitlockite-type structure were synthesized by a standard solid-state method. The unit-cell parameters were determined by X-ray powder diffraction and using Le Bail decomposition. The crystal structural of Ca6.5Pb1.5ZnBi(VO4)7 was refined by Rietveld method. It is found that Pb2+ cations occupy a half of the M3 site, whereas the M1 and M2 sites are predominantly occupied by calcium with admixture of Bi3+ cations. The M5 site is fully occupied by Zn2+ cations. The M4 site in the structure of studied sample remains vacant and does not participate in the cations arrangement. Optical second harmonic generation demonstrates high non-linear optical activity. Dielectric investigations confirm polar space group R3c. Changes in the non-linear optical and ferroelectric parameters are matched with lead and zinc cation distribution over the sites of the whitlockite-type structure.

As we celebrate the 75th anniversary of the Powder Diffraction File, the PDF® is still a method for chemical and material analyses. The database and embedded software are designed to solve a range of solid-state material analysis problems that includes phase identification, quantitative analysis, crystallinity, and crystallite size measurements. A versatile platform allows users to interpret X-ray, electron, neutron, or synchrotron diffraction patterns for their analyses. Over several decades as diffraction hardware and software continued to improve, the International Centre for Diffraction Data continues to improve the methods and the PDF database, offering unprecedented analysis capabilities to the modern user.

The present work focuses on the deformation and recovery mechanisms of aged monoclinic U–Nb alloy under tension and load–unload cycle testing using in situ X-ray diffraction (XRD). The U–6.2wt% Nb (U–6.2Nb) alloy was prepared and aged at 200 °C, and then underwent tensile testing followed by the in situ XRD. The experimental results indicate that the change of diffraction peaks can serve to accurately characterize the macroscopic deformation and recovery. Compared with the as-quenched alloy, the aged U–6.2Nb alloy displays different behavior during deformation and subsequent recovery. Phase transformation competes with twin rearrangement to dominate the deformation and recovery between elastic stage and slip stage of the alloy. The lattice plane relationship between α″ and γ° during phase transformation has also been given.

In this paper, some results of neutron diffraction properties of the double-crystal Si(111) + Si(311) setting containing two bent perfect crystals, but with the second one – analyzer in the fully asymmetric diffraction geometry are presented. Both fully asymmetric diffraction geometries, with the output beam compression as well as the output beam expansion, were tested for the sake of possible applications.