Novel plate-stratiform nanostructured Bi12O17Cl2 was studied with its visible-light photocatalytic performance. The Bi12O17Cl2 photocatalyst synthesized by a solid-state reaction was constructed of dozens of primary nanosheets, which were stacked by a parallel array of ultrathin secondary nanosheets. The microstructure and crystal structure of Bi12O17Cl2 primary and secondary nanosheets were discovered by high-resolution transmission electron microscopy and selected-area electron diffraction analyses. Its absorption edge was determined as about 590 nm and the band gap energy was 2.1 eV. The Bi12O17Cl2 nanomaterial exhibited superior visible-light-responsive photocatalytic activity and confirmed successful photodegradation of methyl orange (MO) under visible-light irradiation. The degradation efficiency was up to 97% in 90 min. Furthermore, the Bi12O17Cl2 photocatalyst exhibited excellent photostability and high mineralization capacity for MO photodegradation reaction. The MO photodegradation process was dominated by the direct photocatalytic mechanism. The contribution from its morphology and microstructure to superior photocatalytic activity was discussed.

High-temperature X-ray diffraction with concurrent gas chromatography (GC) was used to study cobalt disulfide cathode pellets disassembled from thermal batteries. When CoS2 cathode materials were analyzed in an air environment, oxidation of the K(Br, Cl) salt phase in the cathode led to the formation of K2SO4 that subsequently reacted with the pyrite-type CoS2 phase leading to cathode decomposition between ~260 and 450 °C. Independent thermal analysis experiments, i.e. simultaneous thermogravimetric analysis/differential scanning calorimetry/mass spectrometry (MS), augmented the diffraction results and support the overall picture of CoS2 decomposition. Both gas analysis measurements (i.e. GC and MS) from the independent experiments confirmed the formation of SO2 off-gas species during breakdown of the CoS2. In contrast, characterization of the same cathode material under inert conditions showed the presence of CoS2 throughout the entire temperature range of analysis.

The structure of a series of lanthanide iron cobalt perovskite oxides, R(Fe0.5Co0.5)O3 (R = Pr, Nd, Sm, Eu, and Gd), have been investigated. The space group of these compounds was confirmed to be orthorhombic Pnma (No. 62), Z = 4. From Pr to Gd, the lattice parameter a varies from 5.466 35(13) Å to 5.507 10(13) Å, b from 7.7018(2) to 7.561 75(13) Å, c from 5.443 38(10) to 5.292 00(8) Å, and unit-cell volume V from 229.170(9) Å3 to 220.376(9) Å3, respectively. While the trend of V follows the trend of the lanthanide contraction, the lattice parameter “a” increases as the ionic radius r(R3+) decreases. X-ray diffraction (XRD) and transmission electron microscopy confirm that Fe and Co are disordered over the octahedral sites. The structure distortion of these compounds is evidenced in the tilt angles θ, ϕ, and ω, which represent rotations of an octahedron about the pseudocubic perovskite [110]p, [001]p, and [111]p axes. All three tilt angles increase across the lanthanide series (for R = Pr to R = Gd: θ increases from 12.3° to 15.2°, ϕ from 7.5° to 15.8°, and ω from 14.4° to 21.7°), indicating a greater octahedral distortion as r(R3+) decreases. The bond valence sum for the sixfold (Fe/Co) site and the eightfold R site of R(Fe0.5Co0.5)O3 reveal no significant bond strain. Density Functional Theory calculations for Pr(Fe0.5Co0.5)O3 support the disorder of Fe and Co and suggest that this compound to be a narrow band gap semiconductor. XRD patterns of the R(Fe0.5Co0.5)O3 samples were submitted to the Powder Diffraction File.

Kesterite-type compound semiconductors, containing copper and zinc, have photovoltaic properties depending on cation distribution in the crystal structure. Anomalous diffraction allows discrimination of isoelectronic cations, in principle allowing a straightforward determination of site occupation factors from data collected at multiple energies close to the X-ray absorption edges of copper and zinc. However, extremely strong correlation between structural parameters precludes this. We present a recipe based on the direct dependency between refined occupation factors and atomic scattering power, which allows to lift the correlations and to detect issues of individual diffraction patterns or assumptions in the model, thereby allowing for reliable quantitative analysis of the Cu/Zn distribution.

The crystal structure of rivastigmine hydrogen tartrate has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional techniques. Rivastigmine hydrogen tartrate crystallizes in space group P21 (#4) with a = 17.538 34(5), b = 8.326 89(2), c = 7.261 11(2) Å, β = 98.7999(2)°, V = 1047.929(4) Å3, and Z = 2. The un-ionized end of the hydrogen tartrate anions forms a very strong hydrogen bond with the ionized end of another anion to form a chain. The ammonium group of the rivastigmine cation forms a strong discrete hydrogen bond with the carbonyl oxygen atom of the un-ionized end of the tartrate anion. These hydrogen bonds form a corrugated network in the bc-plane. Both hydroxyl groups of the tartrate anion form intramolecular O–H⋯O hydrogen bonds. Several C–H⋯O hydrogen bonds appear to contribute to the crystal energy. The powder pattern is included in the Powder Diffraction File™ as entry 00-064-1501.

We have used conventional X-ray powder diffraction to study one of the largest volume inorganic mixed oxide unit-supercell structures done so far. This necessitated some small-angle X-ray scattering-like observations at low angles from <2° 2θ to concord with electron diffraction, which had indicated an 8 × 8 × 8 huge volume supercell of a fluorite-type basic sub-cell. Emphasis is on the detection of, possibly very weak, fingerprint, low-angle/long lines/peaks which will indicate the (often unsuspected) presence of complex polytypic arrangements of simple very strong basic sub-cells and so facilitate future synthetic studies.

The deflection (curvature) of embedded single-crystal silicon chips was investigated by rocking curve X-ray diffraction techniques at two significant manufacturing stages in the process chain of printed circuit boards with embedded components. An overview of the curvature deduction by two different approaches was presented: (1) the measurement of the variation of the rocking curve maximum as a function of the lateral sample position along a specific traverse; the slope in such a diagram is then proportional to the corresponding curvature in that direction. (2) The evaluation of the rocking curve width; here the peak width is inversely proportional to the curvature at known beam diameter, diffraction angle, and beam divergence. It was shown that the rocking curve method is applicable to determine the curvature inside single crystalline chips. Furthermore, the method is also suitable to determine the curvature of fully embedded or encapsulated chips. Additionally the absorption of the radiation in the embed medium was quantitatively discussed. The curvature of two different prepared samples was determined at temperatures up to 200 °C in a heating stage attached to the diffractometer device.

The crystal structure of citalopram hydrobromide has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional theory techniques. Citalopram hydrobromide crystallizes in space group P21/c (#14) with a = 10.766 45(6), b = 33.070 86(16), c = 10.892 85(5) Å, β = 90.8518(3)°, V = 3878.03(4) Å3, and Z = 8. N–H⋯Br hydrogen bonds are important to the structure, but the crystal energy is dominated by van der Waals attraction. The powder pattern was submitted to International Centre for Diffraction Data for inclusion in the Powder Diffraction File™.

Many technological applications of austenitic shape memory alloys (SMAs) involve cyclical mechanical loading and unloading in order to take advantage of pseudoelasticity. In this paper, we investigated the effect of mechanical bending of pseudoelastic NiTi SMA wires using high-energy synchrotron radiation X-ray diffraction (SR-XRD). Differential scanning calorimetry was performed to identify the phase transformation temperatures. Scanning electron microscopy images show that micro-cracks in compressive regions of the wire propagate with increasing bend angle, while tensile regions tend not to exhibit crack propagation. SR-XRD patterns were analyzed to study the phase transformation and investigate micromechanical properties. By observing the various diffraction peaks such as the austenite (200) and the martensite ( ${\bar 1}12$ ), ( ${\bar 1}03$ ), ( ${\bar 1}11$ ), and (101) planes, intensities and residual strain values exhibit strong anisotropy, depending upon whether the sample is in compression or tension during bending.

The Rietveld method based on X-ray diffraction (XRD) technology has been commonly applied for the quantitative analysis of crystalline minerals in organic-rich rocks. The presence of organic matter, however, has interference in varying degree to the quantitative result. In this work, the mixed samples of organic matter and crystalline minerals at given proportions were prepared to investigate the effect of organic matter on the Rietveld quantitative analysis of crystalline minerals in coal gangue. The relative standard deviation (RSD) and absolute error (AE) were used to evaluate the precision and accuracy of the quantitative result. The results showed that the presence of organic matter led to a reduction in the precision and accuracy. It was attributed in part to the presence of organic matter, which can produce a background noise in the XRD pattern, especially in the region of 5–30° (2θ). Further results showed that the interference in this region increased with the increase in the organic matter content. The RSD and AE were within the range of 10% and 2%, respectively, when the organic matter content is <30 wt%. Based on this, an approximate method for the Rietveld quantitative analysis of crystalline minerals in coal gangue was established.

The crystal structure of norgestimate has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional techniques. Norgestimate crystallizes in space group P212121 (#19) with a = 11.523 67(9), b = 16.130 72(20), c = 22.247 93(20) Å, V = 4135.56(7) Å3, and Z = 8. There are two independent molecules in the asymmetric unit, with opposite conformations of the acetate groups. Molecule 2 is 7.3 kcal mole−1 lower in energy than molecule 1, and is in the minimum energy conformation. The hydroxyimine groups form O–H⋯O hydrogen bonds to the acetate carbonyl groups, resulting in two separate C(15) chains along the b-axis. The powder pattern is included in the Powder Diffraction File™ as entry 00-064-1503.

N- and p-type filled-skutterudite materials prepared for thermoelectric power generation modules were analyzed by neutron diffraction at the POWGEN beam line of the Spallation Neutron Source (SNS) and X-ray diffraction (XRD). The skutterudite powders were processed by melt spinning, followed by ball milling and annealing. The n-type material consists of Ba–Yb–Co–Sb and the p-type material consists of Di–Fe–Ni–Sb or Di–Fe–Co–Sb (Di = didymium, an alloy of Pr and Nd). Powders for prototype module fabrication from General Motors and Marlow Industries were analyzed in this study. XRD and neutron diffraction studies confirm that both the n- and p-type materials have cubic symmetry. Structural Rietveld refinements determined the lattice parameters and atomic parameters of the framework and filler atoms. The cage filling fraction was found to depend linearly on the lattice parameter, which in turn depends on the average framework atom size. This knowledge may allow the filling fraction of these skutterudite materials to be purposefully adjusted, thereby tuning the thermoelectric properties.

Quantitative phase analysis (QPA) using neutron powder diffraction more often than not involves non-ambient studies where no sample preparation is possible. The larger samples and penetration of neutrons versus X-rays makes neutron diffraction less susceptible to inhomogeneity and large grain sizes, but most well-characterized QPA standard samples do not have these characteristics. Sample #4 from the International Union of Crystallography Commission on Powder Diffraction QPA round robin was one such sample. Data were collected using the POWGEN time-of-flight (TOF) neutron powder diffractometer and analysed together with historical data from the C2 diffractometer at Chalk River. The presence of magnetic reflections from Fe3O4 (magnetite) in the sample was an additional consideration, and given the frequency at which iron-containing and other magnetic compounds are present during in-operando studies their possible impact on the accuracy of QPA is of interest. Additionally, scattering from thermal diffuse scattering in the high-Q region (<0.6 Å) accessible with TOF data could impact QPA results during least-squares because of the extreme peak overlaps present in this region. Refinement of POWGEN data was largely insensitive to the modification of longer d-spacing reflections by magnetic contributions, but the constant-wavelength data were adversely impacted if the magnetic structure was not included. A robust refinement weighting was found to be effective in reducing quantification errors using the constant-wavelength neutron data both where intensities from magnetic reflections were ignored and included. Results from the TOF data were very sensitive to inadequate modelling of the high-Q (low d-spacing) background using simple polynomials.

Subsolidus phase equilibrium of Na2O–Sm2O3–B2O3 system has been investigated mainly by solid-state reaction and powder X-ray diffraction method. There are nine definite three-phase regions and three ternary compounds determined under present experimental conditions. A novel compound Na3SmB2O6 was found and confirmed in this system, along with its two homogeneous compounds Na3REB2O6 (RE = Pr, Eu) synthesized for the first time. The indexing results showed that all three compounds crystallize in the monoclinic space group P21/c (No.14) with the same structure type as both Na3NdB2O6 and Na3GdB2O6. The lattice parameters (a, b, and c) of new borates Na3REB2O6 (RE = Pr, Sm, Eu) decrease linearly with a decreasing radius of RE ion, which obeys the Lanthanide-contraction rule. The existence of a trigonal BO3 group in the Na3REB2O6 (RE = Pr, Sm) compounds was confirmed by analysis of their infrared absorption spectra. Thermal stabilities of the three new borates have been investigated.

X-ray reference powder patterns and structures have been determined for a series of cobalt-, nickel- and zinc-containing niobates, Co(NixZn1−x)Nb4O12 (x = 0.2, 0.4, 0.6, 0.8). The Co(NixZn1−x)Nb4O12 series crystallize in the space group of Pbcn, which is of the disordered columbite-type structure (α-PbO2). The lattice parameters range from a = 14.11190(13) to 14.1569(3) Å, b = 5.69965(6) to 5.71209(13) Å, c = 5.03332(5) to 5.03673(11) Å, and V = 404.844(8) to 407.296(17) Å3 from x = 0.8 to 0.2, respectively. Co(NixZn1−x)Nb4O12 contains double zig-zag chains of NbO6 octahedra and single chain of (Ni,Zn,Co)O6 octahedra run parallel to the bc-plane. Within the same chain the NbO6 octahedra share edges, while the adjacent NbO6 chains are joined to each other through common oxygen corners. These double NbO6 chains are further linked together along the [100]-direction through another (Co,Ni,Zn)O6 units, via common oxygen corners. The edge-sharing (Co,Ni,Zn)O6 also forms zig-zag chains along the c-axis. Powder X-ray diffraction patterns of this series of compounds have been submitted to be included in the Powder Diffraction File.

Pb0.88 Ln 0.08TiO3 ferroelectric system, where Ln = La, Sm, Eu, and Dy, has been characterized using Scanning Electron Microscopy, Raman spectroscopy, and X-ray diffraction experiments. Softening of the lowest transverse optical phonon mode E (1TO) was evaluated as a function of the rare earths’ ionic radius suggesting partial occupation of lanthanide ions at the A and B sites of the perovskite structure. Using Rietveld refinements, it has been established a higher incorporation of Ln3+ ions into the A sites of the perovskite structure than that of the B sites for the studied ceramics. The occupation at B sites increases slightly with the decreases of the ionic radii of the lanthanides.