The crystal structure of new Tb3CuAl3Ge2 quaternary compound was studied by the Rietveld method from powder X-ray diffraction (XRD) data. The Tb3CuAl3Ge2 compound crystallized in the hexagonal Y3NiAl3Ge2-type structure with space group P-62m (no. 189) and lattice parameters a = 7.0041(2) Å, c = 4.1775(1) Å, V = 177.48 Å3. There is only one formula in each unit cell, Z = 1, and the density of Tb3CuAl3Ge2 is ρx = 7.1696 g cm−3. The reliability factors characterizing the Rietveld refinement results are Rp = 6.43%, Rwp = 8.65%, RB = 4.81%, and RF = 4.09%, respectively. The powder XRD data of Tb3CuAl3Ge2 were presented and the reliability of indexation is F30 = 120.9(0.0073, 34).

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.

The indexed powder diffraction pattern and related crystallographic data for polymorphic form 2 of carnidazole (C8H12N4O3S) are reported, as a first step in the structure determination by powder diffraction methods. The unit cell dimensions were determined from high resolution synchrotron powder diffraction data (λ=0.079 998 0 nm) and evaluated by indexing programs. The monoclinic cell found for this polymorph is a=1.3908(2) nm, b=08094(2) nm, c=1.0645(2) nm, β=110.82(2)°,V=1.12015(27)nm3, Z=4, Dx=1.445 Mg∕m3.

A synthetic catalyst precursor formed by sulfiding ferrihydrite (Fe3+O(OH)) in the presence of a hydrogen donor produces X-ray diffraction patterns resembling a mixture of both naturally occurring FeS2 polymorphs marcasite and pyrite. The diffraction peaks display a differential broadening, however, wherein only those peaks coincident to both marcasite and pyrite are strong and sharp, a feature that cannot be accounted for by a simple physical mixture. The broadening is analogous to that found in hexagonal cobalt, where occasional stacking faults produce interstratification of the hexagonal and cubic close-packed forms, resulting in strongly coherent diffraction only along the stacking direction. The crystal structures of marcasite and pyrite are virtually identical if viewed perpendicular to the (101) and (001) planes, respectively. Calculation of diffraction patterns based upon models of interstratifying marcasite and pyrite layers along these planes demonstrates that a sequence with marcasite-to-pyrite and pyrite-to-marcasite stacking fault probabilities of 0.22 provides a good fit to the experimental pattern. This interstratified material is a precursor to a species that shows catalytic activity for cleaving C-C bonds between aromatic rings and benzylic carbon atoms at low (<350 °C) temperatures.

X-ray diffraction methods have been used successfully for the analysis of platinum silicide films of 100 Å or less in thickness. Conventional X-ray diffraction was utilized for phase identification, planar orientation, and crystalline size determination. Low-angle X-ray specular reflectivity analysis measured film thickness. As the nominal film thickness approached 100 Å, it was observed that the deposited platinum film thickness was larger than expected and longer anneal times would be required to ensure homogeneous platinum silicide phase composition.

Li(1−2x)NixTiO(PO4) oxyphosphate powders were prepared from dilute solutions of NiCl2⋅6H2O, Li2CO3, (NH4)2HPO4, and TiCl4 in ethanol. The final temperature was 850 °C. Li(1−2x)NixTiO(PO4) oxyphosphates with 0≤x≤0.10 crystallize in the orthorhombic system with space group Pnma, while those with 0.10<x≤0.25 crystallize in the monoclinic system with space group P21/c.

The results of an international project involving five countries and seven laboratories performing over 400 analyses for testing the interlaboratory reproducibility and accuracy using quantitative powder diffraction are presented in this report. Four natural and four artificial mineral mixtures were examined. The RIR (reference intensity ratio) values for all mineral components were either measured or calculated. The relative standard deviation of the interlaboratory determinations range from 5 to 20 percent (for low concentrations, the relative standard deviations can attain 60% percent). Due to systematic errors, the relative standard deviations of the interlaboratory determinations generally exceed the standard deviations determined by individual laboratories. The best results were obtained when the RIR values were measured independendy in each laboratory.

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.

Two new thiophosphates with an original structure corresponding to formula ATi2(PS4)3 (with A=Na,Ag) were synthesized by solid-state reaction. The two compounds are isostructural, hexagonal space group P6cc, Z=8. A single crystal of NaTi2(PS4)3 has been studied. Unit-cell parameters were determined for NaTi2(PS4)3 and AgTi2(PS4)3, respectively: a= 19.9131(6) Å, c= 11.5542(7) Å, V=3967.8(3) Å3 and a=20.0146(8) Å, c= 11.5467(8) Å, V=4005.7(4) Å3. Powder diffraction data are reported.

Crystal data for four p-dibromobenzene/p-chloroiodobenzene mixed crystals, (pDBB)x(pCIB)1-x, with x = 0.1, 0.4, 0.7, 0.9, synthesized by the fusion-quenching method, and a typical powder diffraction pattern are reported. The unit cell is monoclinic with S.G. = P21/a and Z = 2. Cell parameters of solid solution members varied almost linearly between the end member values.

A comparison of X-ray powder diffraction and electron probe microanalyses on samples of Na- and K-doped Bi4V2O11 (BIMEVOX) solid electrolytes indicates some of the problems associated with using XRD to assess phase purity, especially in materials of variable composition such as BIMEVOXes. In this study both the Na- and K-doped materials appeared phase pure by XRD. EPMA indicated the Na-doped materials to be single phase with their expected compositions while the K-containing materials were not phase pure with very little K present in the main BIMEVOX phase.

The crystal structure of MoO2(O2)(H2O)·H2O has been solved using parallel tempering with the FOX software package and refined using synchrotron powder diffraction data obtained from beamline 08B1-1 at the Canadian Light Source. Rietveld refinement, performed with the software package GSAS, yielded monoclinic lattice parameters of a = 17.3355(5) Å, b = 3.83342(10) Å, c = 6.55760(18) Å, and β = 91.2114(27)° (Z = 4, space group I2/m). The structure is composed of double zigzag molybdate chains running parallel to the b-axis. The Rietveld refined structure was compared with density functional theory (DFT) calculations performed with CRYSTAL14, and shows comparable agreement with two DFT optimized structures of similar energy, which differ by the location of the molybdate coordinated water molecule. The true structure is likely a disordered combination of the two DFT optimized structures.

X-ray powder data are given for glucopyranosylsorbitol, C12H24O11, and glucopyranosylmannitol dihydrate, C12H24O11 * 2H2O. Refined unit cell parameters for glucopyranosylsorbitol are: a=0.9124(4) nm, b=1.1336(5) nm, c=0.7232(3) nm, and β=91.23(4)° in space group P21 and those for glucopyranosylmannitol dihydrate are a=2.2579(15) nm, b=1.0016(5) nm, and c=0.7584(5) nm in space group P212121.

Transparent p-type conducting Ga-doped SnO2 thin films were prepared using reactive rf-magnetron sputtering. Good p-type conduction was directly realized without the need of postdeposition annealing. The p-type conductivity was found to be very sensitive to the growth condition and process, suggesting that the carrier behavior is strongly related to the fine microstructure of the films. The microstructures of the films were characterized using synchrotron X-ray diffraction and specular reflectivity techniques. The valence state of the Ga dopant was measured from X-ray photoelectron spectra to explain the origin of net holes presented in the films.

X-ray powder diffraction and optical data are presented for a vanadium-rich dravite from Silver Knob, Mariposa County, California, U.S.A. The limited compositional variability observed for vanadium-rich dravite is due to the presence of a Tschermaks substitution whereby the substitution of Al for Si in the tetrahedral ring is charge balanced by trivalent for divalent cation substitution in the octahedral sites in the structure. Vanadium-rich dravite is uniaxial negative with ε = 1.646(2) and ω = 1.676(2). Refined unit cell dimensions are a = 15.9599(10) and c = 7.1889(2); F30 = 111(0.009; 30); M20 = 80; and Dx = 3.07. An indexed X-ray powder diffraction pattern is also presented.