Five new aliphatic-aromatic thiodiols: 1,2-bis[4-(2′-hydroxyethylthio)phenyl]ethane (C18H22O2S2), 1,2-bis[4-(3′-hydroxypropylthio)phenyl]ethane (C20H26O2S2), 1,2-bis[4-(6′-hydroxyhexylthio)phenyl]ethane (C26H38O2S2), 1,2-bis[4-(10′-hydroxydecylthio)phenyl]ethane (C34H54O2S2), 1,2-bis[4-(11′-hydroxyundecylthio)phenyl]ethane (C36H58O2S2) have been characterized by X-ray powder diffraction. These thiodiols can be used for synthesis of thermoplastic nonsegmented polyurethanes. Experimental 2θ peaks positions, relative peak intensities, values of d and Miller indices as well as unit cell parameters are reported.

The technique of standard addition in combination with powder X-ray diffraction was used to identify and quantify the amount of Ln3+ segregating into secondary phases from Ln3+doped alkaline earth aluminates. Results indicate that Ln3+ ions are more soluble in CaAl2O4 than SrAl2O4 and BaAl2O4, with this being rationalized by the structural details of the A sites. These results indicate that the enhancement of the luminescence afterglow obtained by doping AAl2O4:Eu2+ samples with Ln3+ ions is a result of much lower doping levels than previously thought.

X-ray diffraction, selected area electron diffraction, and high-resolution transmission electron microscope techniques were used to investigate the crystalline structures of one-dimensional tungsten oxide nanowires prepared by the hydrothermal method. The as-synthesized products were found to exhibit increasing crystallinity with increasing reaction time, and tungsten oxide nanowires have crystalline defects, including stacking faults, dislocations, and vacancies. The results on the crystal defects help us to obtain a better understanding of the temperature-dependent morphological evolution of the ultrathin nanowires synthesized under different thermal processes.

The X-ray powder diffraction patterns for tetramethylammonium bromide and iodide have been measured from near room temperature up to decomposition/sublimation. The unit cell parameters were refined and the coefficients of thermal expansion calculated. Unlike N(CH3)4Cl [M. Stammler, J. Inorg. Nucl. Chem. 29, 2203–2221 (1967)], N(CH3)4Br (1Br) and N(CH3)4I (1I) undergo no solid–solid transitions before decomposition/sublimation as was observed earlier by thermal analysis [S. S. Chang and E. F. Westrum, J. Chem. Phys. 36(9), 2420–2423 (1962); Coulter etal., J. Am. Chem. Soc. 62, 2845–2851 (1940); Xenopoulos etal., Mol. Cryst. Liq. Cryst. 214, 63–79 (1992)].

The crystal structure of Cr2[Ni(CN)4]3·10H2O has been determined on X-ray diffraction powder data by means of the Rietveld method. The starting model was based on the isomorphic, disordered structure of Mn3[Co(CN)6]2·12H2O. At room temperature the crystal is cubic, F4¯3m, a=10.097(6) Å, V=1029.4(5) Å3. The structure is disordered and contains 1.33 formula weights per unit cell. The Ni and Cr ions are coordinated by N and C atoms, respectively, forming octahedra linked by CN groups. The water molecules replace partly the chromium, carbon, and nitrogen positions in the crystal. The final R values are: Rwp=0.032 (Rexp=0.023), RB=0.088, and DW-Stat.=1.31 (DWexp=1.8).

A new Ca1/3Sb1/6Bi1/2PO4 “CaSb0.50Bi1.50(PO4)3” phosphate has been synthesized by conventional solid-state reaction techniques at 900 °C in air atmosphere. Their crystallographic structures were determined at room temperature from X-ray powder diffraction (XRPD) data using the Rietveld analysis. CaII 1/3SbV 1/6BiIII 1/2PO4 material possesses the high-temperature BiPO4 monoclinic structure variety. It crystallizes in monoclinic system with P21/m space group and the cell parameters are: a = 4.9358(1) Å, b = 6.9953(2), c = 4.7075(1) Å, and β = 96.2(1)°. Their structure can be described as composed of alternating edge-sharing AO8 (A = Ca, Sb, Bi) bisdisphenoids and PO4 tetrahedra forming chains parallel to the b axis. Every AO8 polyhedron is surrounded by six PO4 and every PO4 tetrahedron is surrounded by six AO8 polyhedra. Infrared spectroscopic study was used to obtain further structural information.

Materials in a high radioactive environment undergo structural changes. X-ray diffraction (XRD) is commonly used to study the micro-structural changes of such materials. Therefore, a safe procedure is required for the preparation of specimens. In this paper, a simple methodology for the preparation of radioactive powder specimens to be analyzed in a non-nuclearized laboratory diffractometer is presented. The process is carried out inside a shielded glove box, where the milling of the radioactive sample and specimen preparation occurs. Minimum amount of sample is required (<20 mg), which is drop-casted on a polyether ether ketone (PEEK) foil and glue-sealed inside a disposable plastic holder for a safe handling of the specimen. One example using neutron-irradiated granite is shown, where unit-cell parameters and crystal density of the main phases were calculated. The developed methodology represents an easy and affordable way to study neutron irradiated materials with low activity at laboratory scale.

The giant gypsum crystals of Naica cave have fascinated scientists since their discovery in 2000. Human activity has changed the microclimate inside the cave, making scientists wonder about the potential environmental impact on the crystals. Over the last 9 years, we have studied approximately 70 samples. This paper reports on the detailed chemical–structural characterization of the impurities present at the surface of these crystals and the experimental simulations of their potential deterioration patterns. Selected samples were studied by petrography, optical and electronic microscopy, and laboratory X-ray diffraction. 2D grazing incidence X-ray diffraction, X-ray μ-fluorescence, and X-ray μ-absorption near-edge structure were used to identify the impurities and their associated phases. These impurities were deposited during the latest stage of the gypsum crystal formation and have afterward evolved with the natural high humidity. The simulations of the behavior of the crystals in microclimatic chambers produced crystal dissolution by 1–4% weight fraction under high CO2 concentration and permanent fog, and gypsum phase dehydration under air and CO2 gaseous environment. Our work suggests that most surface impurities are of natural origin; the most significant anthropogenic damage on the crystals is the extraction of water from the caves.

Exact and approximate mathematical models for the effects of sample transparency on the powder diffraction intensity data are examined. Application of the formula based on the first-order approximation about the deviation angle is justified for realistic measurement and computing systems. The effects of sample transparency are expressed by double convolution formulas applying two different scale transforms, including three parameters, goniometer radius R, penetration depth μ−1, and thickness of the sample t. The deconvolutional treatment automatically recovers the lost intensity and corrects the peak shift and asymmetric deformation of peak profile caused by the sample transparency.

Cement references were reviewed and whole pattern methods were developed for the quantitative phase analysis (QPA) of Type I Portland Cements. A set of control references were established for phase identification and quantitative analysis using laboratory diffractometers. Both RIR and Rietveld whole pattern fitting methods were used in the analyses. A block refined, parameter restricted, Rietveld method produced the best QPA results by comparison with known mixtures. Similar to prior literature findings, care has to be taken because of the severe peak overlap of the major calcium silicate and calcium aluminate phases in Portland cement and the complexity of the chemistry and structures involved. Two of the four major phases identified are doped supercells and the major C3S phase is also disordered.

The triplite LiFeSO4F displays both the highest potential ever reported for an Fe-based compound, as well as a comparable specific energy with that of popular LiFePO4. The synthesis is still a challenge because the present approaches are connected with long time, special equipments or organic reagents, etc. In this work, the triplite LiFeSO4F powder was synthesized through an ambient two-step solid-state route. The reaction process and phase purity were analyzed, coupled with structure refinement and electrochemical test.

An anisotropic line broadening study of CuO is reported. X-ray powder diffraction line width modifications observed are modeled when comparing data coming from (1) commercial analytical grade CuO, (2) energetic ball milling sample for 1 h, and (3) samples prepared by thermally annealing the ball milled sample at various temperatures. X-ray powder diffraction data from commercial and produced samples were analyzed by the Rietveld method using a pseudo-Voigt function. Different assumptions including size and strain anisotropy were tried to improve pattern fitting. An anisotropic strain broadening, modeled using Stephens’ approximation, yielded the best fit, thus indicating that strain anisotropy is the main source of the departure from a smooth function of line broadening as a function of 2θ observed in all samples.

I have made use of X-ray powder diffraction patterns for over sixty years. In the summer of 1922, in anticipation of my becoming a graduate student in chemistry, I read the book “X-Rays and Crystal Structure,” by W. H. and W. L. Bragg. Then in September 1922 I arrived in Pasadena, and immediately began to learn how to determine the structure of a crystal by a study of the X-ray diffraction pattern from Roscoe Gilkey Dickinson, who was the first person to have received a Ph.D. degree from the California Institute of Technology (1920). The procedure in use in Pasadena started with the preparation of a photograph showing lines obtained by Bragg reflection from a developed face of a large crystal with monochromatic radiation, usually molybdenum K alpha and beta. Measurement of the angle of reflection gave a set of possible values for the length of the edges of the unit of structure, usually of a cubic, hexagonal, or tetragonal crystal, since the methods were not powerful enough to permit the evaluation of more than two or three parameters. The next step was the preparation of Laue photographs, and their analysis. This was a powerful method, which often led to the correct structures.

Sodium Calcium Magnesium Silicate, Na2Ca4Mg2Si4O15, has been investigated by means of X-ray powder diffraction. Data were obtained by a conventional diffractometer. Unit cell dimensions were determined by an indexing program. A monoclinic cell was found, a = 17.884(2) Å, b = 5.3573(8) Å, c = 7.1796(8) Å, β = 112.71 (1)°; V=634.56 A3.

A new ternary compound Al0.35GdGe2 has been synthesized and studied by means of X-ray powder diffraction technique. The ternary compound Al0.35GdGe2 crystallizes in the orthorhombicwith the CeNiSi2 structure type (space group Cmcm, a=4.0874(2) Å, b=16.1499(5) Å,c=3.9372(1) Å, Z=4, and Dcalc=8.007 g/cm3).

Complete X-ray powder data is recorded from type specimens of the minerals nissonite and waylandite. Debye-Scherrer films of 114.59 mm diameter were measured with an automated densitometer. A wide step width of 0.08°2θ was required, because the average reflection width at half height was 0.5°2θ. The 2θ positions and relative intensities of the reflections were calculated from a negative second derivative function based upon a five point curve.

Thulium (Tm) doped barium yttrium ytterbium fluoride (BaYYbF8:Tm) thin films have been deposited on (100) silicon (Si) or (100) and (111) gallium arsenide (GaAs) substrates. When deposited on (100) Si, with an intermediate amorphous silicon dioxide (SiO2) layer, the BaYYbF8:Tm film was found to be polycrystalline, crystallizing in a previously unobserved cubic phase with a lattice constant a = 11.4208 (9) Å . Films deposited on GaAs, with an intermediate calcium fluoride (CaF2) layer, showed a high degree of planar orientation. Pole figure analysis revealed that the BaYYbF8:Tm films deposited on CaF2/GaAs are in-plane aligned dependent upon the substrate orientation.

After regeneration, the catalyst UOP-R-62 was used for conversion of reforming benzine. The percentage of conversion benzine fraction was considerably smaller than that of the new catalyst sample. To determine the cause of catalyst deactivation, in addition to standard methods of analysis, X-ray diffraction and scanning electron microscopy were used. Real and model samples of UOP-R-62 were analysed. Real samples were prepared with the new catalyst, a used and regenerated catalyst with good activity and a deactivated catalyst. Model samples were prepared from the new catalyst by heating at 400–1100 °C in a porcelain crucible in a muffle furnace for 1 h. Prepared samples were measured in a Philips diffractometer system and examined in a scanning electron microscope. The obtained diffractometer patterns, FWHM value of the 440 reflection of γAl2O3, electron micrographs and images of emitted characteristic X-rays were mutually compared. Only the values obtained from the deactivated catalyst differed from the others. Besides reduced broadening of the 440 line the material exhibited new X-ray diffraction lines, a change in phase composition, and modifications in morphology and microstructure. These changes are an indication that overheating of individual spheres of catalyst UOP-R-62 to a temperature of 700—1100 °C or higher caused their deactivation.