K3Al3F12⋅nH2O (n=2,1) are the successive products of the thermal decomposition of K(H3O)2AlF6. Both structures are orthorhombic, built up from disconnected hexagonal-tungsten-bronze (HTB)-related layers, with K+ cations and H2O molecules inserted between. For n=2, there are two disconnected layers along a presenting different octahedra tilting [a=13.5135(2) Å, b=7.0433(1) Å, c=12.2252(2) Å, V=1163.60(3) Å3, Z=4, space group Pnma], whereas for n=1, the stacking is reduced to only one HTB layer along c [a=7.0523(5) Å, b=12.1005(9) Å, c=6.7057(5) Å, V=572.24(7) Å3 (at 170 °C), Z=2, space group Pmmn] after the departure of one water molecule. The thermodiffractometry ends in the α-KAlF4 form.

A model for the long awaited crystal structure of metastable NaAlF4 is established from the powder diffraction pattern of a partly disproportionated sample. Orthorhombic, Cmcm, a=3.6121(3), b=14.952(1), c=5.2692(4) Å, Z=4, V=284.58(4) Å3. Sodium atoms are in NaF6 trigonal prisms interconnected by edges in compact layers. AlF6 octahedra are both cis- and trans-corner connected forming a layer structure similar to that observed in the NaNbO2F2 (P21/c) and BaZnF4 (Cmc21) structure types. NaAlF4 is ideally simple and symmetrical, isostructural with BiReO4 (Cmcm), representing the aristotype of the NaMIIIF4 and BaMIIF4 series.

A new ternary phase, Er2Cu10.9Ga6.1, has been found in the Er-Cu-Ga phase diagram. X-ray powder diffraction data were successfully refined based on a rhombohedral Th2Zn17 structure type (space group R-3m, No. 166) with cell parameters a=8.6627(1) Å, c=12.6824(2) Å, and Z=3. Er2Cu10.9Ga6.1 exhibits a paramagnetic Curie-Weiss behaviour down to 2 K with a trivalent character of Er atoms.

Crystal structure of 4H-SiC was refined from room-temperature X-ray powder diffraction data using the Rietveld refinement method. The refined lattice constants were determined to be a=b=3.079 93(0) Å, c=10.082 22(2) Å, and the refined overall temperature factor B=0.383(3) Å2. Using the Debye approximation, the Debye temperature was successfully determined to be 1194.8 K.

Preferred orientation or texture is a common feature of experimental powder patterns. The mathematics of two commonly used models for preferred orientation—the March-Dollase and the generalized spherical-harmonic models—is reviewed. Both models were applied individually to neutron powder data from uniaxially pressed molybdite (MoO3) and calcite (CaCO3) powders in Rietveld analyses, as well as the as-received powders. The structural refinement results are compared to single-crystal structures. The results indicate that reasonable refinement of crystal structures can be obtained using either the March model or generalized spherical-harmonic description. However, the generalized spherical-harmonic description provided better Rietveld fits than the March model for the molybdite and calcite. Therefore, the generalized spherical-harmonic description is recommended for correction of preferred orientation in neutron diffraction analysis for both crystal structure refinement and phase composition analysis. Subsequently, the generalized spherical-harmonic description is extended to crystal structure refinement of annealed and the aged polycrystalline Ni-rich Ni50.7Ti49.30 shape memory alloys.

Five new derivatives of N-(ω-hydroxyalkyl)-4-chlorophenoxyacetamide [namely, 2-(4-chlorophenoxy)-N-(2-hydroxyethyl) acetamide, 2-(4-chlorophenoxy)-N-(3-hydroxypropyl) acetamide, 2-(4-chlorophenoxy)-N-[1-(hydroxymethyl) propyl] acetamide, 2-(4-chlorophenoxy)-N-(2-hydroxy-1,1-dimethylethyl) acetamide, and 2-(4-chlorophenoxy)-N-{2-[(2-hydroxyethyl) amino] ethyl} acetamide] and one 2-(4-chlorophenoxy) acetohydrazide have been characterized by X-ray powder diffraction. These organic compounds are potential pesticides. New diffraction data including experimental and calculated 2θ peaks positions, values of d, experimental relative peak intensities, and Miller indices as well as unit-cell parameters are reported.

Tibolone is used for hormone reposition of postmenopause women and isotibolone is considered the major degradation product of tibolone. Isotibolone can also be present in tibolone API raw materials due to some inadequate synthesis. Its presence is then necessary to be identified and quantified in the quality control of both API and drug products. In this work we present the indexing of an isotibolone X-ray diffraction pattern measured with synchrotron light (λ=1.2407 Å) in the transmission mode. The characterization of the isotibolone sample by IR spectroscopy, elemental analysis, and thermal analysis are also presented. The isotibolone crystallographic data are a=6.8066 Å, b=20.7350 Å, c=6.4489 Å, β=76.428°, V=884.75 Å3, and space group P21, ρo=1.187 g cm−3, Z=2.

This paper reports a reference X-ray powder diffraction pattern for a high-pressure phase, CaCo2O4, which has been reported recently to have a large Seebeck coefficient. The structure of CaCo2O4 is orthorhombic with space group Pnma, a=8.789(2) Å, b=2.9006(7) Å, c=10.282(3) Å, V=262.43 Å3, and Dc=5.62 g/cm3. This phase crystallizes in the CaFe2O4-type structure and consists of an edge- and corner-shared CoO6 octahedral network. The reference pattern has been submitted to the Powder Diffraction File (PDF).

A method to characterize iron oxide microparticles by microquantity X-ray powder diffraction is presented. The method employs small sections of acrylic tubing and double sided Mylar® tape that fits over a standard 170 mm collimator for a Bruker-AXS SMART 1000 or APEXII three-circle single-crystal diffractometer (Mo X-ray tube). The tubing will hold and position a sample that is placed on the double-sided Mylar® tape and allow for rapid specimen mounting/dismounting and data collection. The method is simple, portable, and readily adapted to a variety of single-crystal X-ray diffractometers.

The crystal structure of the mullite in a commercial material was refined by the Rietveld method using laboratory X-ray powder diffraction data. In this one refinement, most of the common challenges—including variable stoichiometry (partially occupied sites), multiple impurity phases, amorphous material, constraints, restraints, correlation, anisotropic profiles, microabsorption, and contamination during grinding—are encountered and the thought processes during the refinement are described step-by-step. Interpretation of the refinements includes bulk chemical analysis, chemical composition of the mullite, assessment of the geometry, bond valence sums, the displacement coefficients, crystallite size and microstrain, comparison to similar structures to assess chemical reasonableness, and the nature of the amorphous phase.