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GSAS instrument parameters are tabulated for a variety of laboratory and synchrotron diffractometers to give users an idea of the typical ranges of profile parameters when they generate their own instrument parameter files. For modern high-resolution laboratory diffractometers, the parameters fall in the ranges 0<U<3, V=0, 0<W<4, 1<X<3, 0<Y<3, 1<asym<3, and 0<S/L<0.03. For synchrotron diffractometers, the parameters fall in the ranges 0<U<1.2, −1<V<0, 0<W<1, 0<X<1, 0<Y<1, 0<asym<0.5, 0<S/L<0.001, and 0<H/L<0.007. FULLPROF equivalents are also reported. The factors which are convoluted together to generate the instrument profile are described.
The aim of this work was to design, construct, install, and commission an on-line, X-ray diffraction (XRD) analyzer capable of continuously monitoring phase abundances for use in process plant control. This has been achieved through a joint project between CSIRO Minerals and Fuel & Combustion Technology Pty. Ltd. with an instrument designed for use in a Portland cement manufacturing plant. Key factors in tailoring such an instrument to the cement industry were (i) the handling and presentation of a dry sample and (ii) the development of an analytical method suitable for the complex suite of phases contained within Portland cement. The instrument incorporates continuous flow of sample through the diffractometer using a purpose-built sample presentation stage. The XRD data are collected simultaneously using a wide range (120° 2θ) position sensitive detector, thus enabling rapid collection of the full diffraction pattern. The data are then analyzed using a Rietveld analysis method to obtain a quantitative estimate of each of the phases present. The instrument is controlled by a PC linked to the diffractometer through a purpose built interface. The phase abundance information is then transmitted to the central computer in the cement plant where it can be used for the control of mill parameters such as temperature and retention times as well as gypsum feed rate.
The mixed ligand complexes of manganese(II), nickel(II), copper(II), zinc(II), and cadmium(II) involving aspartic acid and benzoic acid have been synthesized. The complexes were studied by various spectroscopic techniques such as infrared, electronic, X-ray diffraction, and magnetic measurements. The complexes were found to have octahedral geometry. The X-ray powder diffraction results show that the crystal systems of Mn(II)-Asp-Ben complex are hexagonal, and Ni(II)-Asp-Ben, Cu(II)-Asp-Ben, Zn(II)-Asp-Ben, and Cd(II)-Asp-Ben complexes are found to be triclinic. The value of unit-cell parameters and XRD data for the five mixed ligand complexes are reported.
A powder neutron diffraction study has been undertaken for the titled compounds at room temperature. Data were analyzed using the Rietveld method. With increasing Nd content the unit cell has been found to contract very slightly, which is in accordance with the ionic radii of La3+ and Nd3+.
X-ray powder diffraction data, unit cell parameters, and space group for a new platinum-based anticancer complex cis-[bis(acetonitrile)]-[(1R,2R)-1,2-diaminocyclohexane-κN, κN′]platinum (II)nitrate (1:2) monohydrate, cis-[Pt(C2H3N)2(C6H14N2)](NO3)2·H2O, are presented [a=12.638(3) Å, b=12.153(2) Å, c=11.881(3) Å, β=95.145(4)°, space group P21, cell volume=1817.5 Å3, and Z=4]. All measured lines were indexed and are consistent with the P21 space group. No detectable impurities were observed.
Palmierite (K2Pb(SO4)2) has been prepared via a chemical synthesis method. Intensity differences were observed when X-ray powder data from the newly synthesized compound were compared to the published powder diffraction card (PDF) 29-1015 for Palmierite. Investigation of these differences indicated the possibility of preferred orientation and/or chemical inhomogeneity affecting intensities, particularly those of the basal (00l) reflections. Annealing of the Palmierite was found to reduce the effects of preferred orientation. Electron microprobe analysis confirmed K:Pb:S as 2:1:2 for the for the annealed Palmierite powder. Subsequent least-squares refinement and Rietveld analysis of the annealed powder showed peak intensities very close to that of a calculated Palmierite pattern (based on single crystal data), yet substantially higher than many of the PDF 29-1015 published intensities. Further investigation of peak intensity variation via calculated patterns suggested that the intensity discrepancies between the annealed sample and those found in PDF 29-1015 were potentially due to chemical variation in the K2Pb(SO4)2 composition. X-ray powder diffraction and crystal data for Palmierite are reported for the annealed sample. Palmierite is trigonal/hexagonal with unit cell parameters a=5.497(1) Å, c=20.864(2) Å, space group R-3m(166), and Z=3.
Fe–N thin films were deposited on glass substrates by dc magnetron sputtering under various Ar∕N2 discharge conditions. Crystal structures and elemental compositions of the films were characterized by X-ray diffraction and X-ray photoelectron spectroscopy. Magnetic properties of the films were measured using a superconducting quantum interference device magnetometer. Films deposited at different N2∕(Ar+N2) flow ratios were found to have different crystal structures and different nitrogen contents. When the flow ratios were 60%, 50%, and 30%, a nonmagnetic single-phase FeN was formed in the films. At the flow ratio of 10%, two crystal phases of γ′-Fe4N and ε-Fe3N were detected. When the flow ratio reduced to 5%, a mixture of α-Fe, ε-Fe3N, FeN0.056, and α″-Fe16N2 phases was obtained. The value of saturation magnetization for the mixture was found to be larger than that of pure Fe.
A recently developed Rigaku parallel-beam X-ray diffraction system equipped with a parabolic graded-multilayer mirror in the incident beam and a parallel-slits analyzer in the diffracted beam was used for precision high-temperature diffraction studies. The lattice parameters a and c of α-Al2O3 at room temperature and up to 1473 K were determined with precision in the range of 0.6–7.3×10−5. The thermal expansion coefficients for a and c agreed with literature values to better than 3%. The system was used successfully also to determine the Debye characteristic temperature of Si and to study structural phase transition of LaCoO3 from rhombohedral at room temperature to cubic at 1700 K.
New salts of barium with dicarboxylic acids (glutaric, adipic, pimelic, suberic, sebacic, and dodecanedioic) were synthesized and characterized by powder diffraction techniques. In addition to the basic crystallographic data and chemical analyses of barium glutarate hexahydrate {1}, barium adipate {2}, barium pimelate {3}, barium disuberate {4}, barium sebacate {5}, and barium dodecanedioate {6}, the processes of their thermal decomposition were investigated by XRPD. All the compounds decompose to barium carbonate at temperatures between 400 and 500 °C.
Modern powder diffraction employing computer-controlled diffractometers now allows quantitative analytical methods to use the whole diffraction trace rather than only individual peaks. Two such methods are in common use: the Rietveld method, which refines the crystal structures of the component phases as part of the matching calculation, and the pattern-fitting method, which uses reference patterns from a database. Potential accuracies of these methods seems to be around 1% absolute. The most severe limitation on the potential accuracy of these methods is particle statistics, which has been reviewed in considerable detail.
The crystal structures of two manganese hexacyanometallates(II), Mn2[Fe(CN)6].8H2O and Mn2[Os(CN)6].8H2O, were refined from X-ray powder diffraction data using the Rietveld method, with the reported structure for Mn2[Ru(CN)6].8H2O used as a structural model. These compounds are isomorphous and crystallize in the monoclinic space group P21/n. Their crystallization water is not firmly bound and can be removed without disrupting the M–C≡N–Mn network. In the dehydrated complexes, the outer cation (Mn) remains linked to only three N atoms from CN ligands while the inner cation (Fe,Os) preserves its coordination sphere. The IR, Raman, and Mössbauer spectra for the hydrated and anhydrous forms are explained based on the refined structures.
New X-ray powder diffraction patterns for two cholesterol derivatives, cholest-4-ene-3,6-dione and cholest-4-en-3-one are reported in the range 0<2θ<115°. Both compounds crystallize in similar monoclinic cells in space-group P21, with unit cell parameters a=10.481(3) Å, b=8.0354(8) Å, c=14.677(3) Å, β=105.265(7)°, V=1192.5(4) Å3 for C27H42O2, and a=10.703(2) Å, b=7.8750(6) Å, c=14.660(3) Å, β=105.205(14)°, V=1192.4(4) Å3 for C27H44O. The patterns, confirmed by single-crystal studies, do not match the PDF 17-1144 and PDF 10-649. A fitting of the overall parameters was performed with Fullprof using the atomic parameters obtained from single-crystal studies.
Our X-ray powder diffraction data determine that UTeO4 has an orthorhombic unit cell with parameters: a=10.115±0.003 Å, b=10.706±0.002 Å, c=7.833±0.002 Å, and v=848±0.40 (Å)3, i.e., the cell volume twice as large as that of UTeO5. IR spectral studies show that UTeO4 and UTeO5 have almost an identical molecular symmetry. In UTeO4, the effective environment of U and Te remains nearly the same as in UTeO5 and the UO2 group is noncentrosymmetric and nonlinear with little or no interaction with equatorial oxygen. Frequencies of the characteristic stretching bands of UTeO4 are (cm−1): νas (O=U=O)=945, νs (O=U=O)=880, νs (Te–O)eq=818, νas (Te–O)eq=749, νas (Te–O)ax=649, νs (Te–O)ax=561.