bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantitative phase analysis of natural products using whole-powder-pattern decomposition
Authors: Hayashi Shigeo , Toraya Hideo
Published: January 2013

The capability of whole-powder-pattern decomposition in the quantitative phase analysis (QPA) of natural products was investigated using three- to six-component mixtures and pottery bodies. Here, the term pottery body means plastic clay suitable for making pottery and it is compounded of ceramic raw materials. Average errors of the weight fractions for each phase were within 1 weight percent in each mixture of natural products. The amounts of reduced oxides in pottery bodies derived from the X-ray diffraction technique were in good agreement with results obtained by X-ray fluorescence analysis. The present procedure does not require knowledge of crystal structures; it appears adequate for the QPA of natural products.
Powder diffraction data for the germanides CoGe and Co5Ge7
Authors: Audebrand N. , Ellner M. , Mittemeijer E. J.
Published: January 2013

Precise X-ray powder diffraction data are given for two germanides, CoGe and Co5Ge7. The refined unit cell parameters for CoGe are a=11.630(1) Å, b=3.8014(3) Å, c=4.9347(3) Å and β=100.889(8)° (space group C2/m, Pearson symbol mC16) with volume of the unit cell 214.24(2) Å3; the figures of merit are M20=96, F30=77 (0.0085, 46). The refined unit cell parameters for Co5Ge7 are a=7.6262(4) Å and c=5.8017(5) Å (I4mm, tI24) with volume of the unit cell 337.42(3) Å3; the figures of merit are M20=204 and F22=130(0.0068, 25). The dependence on composition of the unit cell parameters of CoGe is discussed in terms of specific defect structures.
An external standard method for angular calibration of powder diffractometers
Authors: Wanguo Wu , Yuzhong Ruan
Published: January 2013

An external standard method using mica for angular calibration of powder diffractometers is described. This is useful especially when standard referee materials certified by the US National Institute of Standards and Technology are not accessible.
Structural characterization of dimercury(1+) pentacyanonitrosylferrate(2−), Hg2[Fe(CN)5NO]
Authors: Venegas V. , Rueda-Morales G. , Reguera E. , Caleyo F.
Published: January 2013

The titled compound, Hg2[Fe(CN)5NO], was synthesized and studied by X-ray powder diffraction, infrared spectroscopy, Mössbauer spectroscopy, and atomic force microscopy. The results arising from this study indicate that this compound is anhydrous and crystallizes in the P222 orthorhombic symmetry. The unit cell parameters were quantified as a=16.5905(9) Å, b=12.3145(8) Å, and c=8.7576(5) Å. The measured and calculated density values are Dm=1.149 g/cm3 and Dc=1.145 g/cm3, respectively, with Z=2.
Improved X-ray powder diffraction data for Ti2AlN
Authors: Gamarnik M. Y. , Barsoum M. W. , El-Raghy T.
Published: January 2013

A complete set of d spacings, intensities, and h, k, l indexes for Ti2AlN has been determined from X-ray powder diffraction. The lattice parameters are a=2.989(2) Å, c=13.614(5) Å; in good agreement with previous work. The new set of results comprises seven reflections not present in the current Ti2AlN PDF card No. 18-70. Furthermore, a new set of relative intensities are reported that are in better agreement with the calculated values than they are with those listed in the PDF card.
Qualitative X-Ray Phase Analysis of Lignite Gasification Ash. Illustration of a Strategy for Analysis of Very Complex Solids
Authors: McCarthy Gregory J.
Published: January 2013

A strategy for qualitative X-ray phase analysis of complex multiphase solids is illustrated through the analysis of eight fixed-bed gasification ashes. Coal from the same lignite formation was gasified in three different reactors. Despite the differences in gasifiers and their operating conditions, all of the ash specimens had the same basic crystalline phase assemblage: silicates and aluminosilicates (merwinite, dicalcium silicates, melilite, nepheline, carnegieite and a sodalite structure phase), oxides (ferrite spinels, hematite and periclase), calcite and residual lignite minerals (quartz, plagioclase). The identification strategy relied on a bulk chemical analysis of each ash and used manual methods with the JCPDS-ICDD search manuals for the Powder Diffraction File. Grain picking, size separations, magnetic enrichment, separation by hardness, dissolution of water soluble phases, and further crystallization of the ash through heat treatment all figured in the identification strategy. Identification of more than a dozen minor and trace phases resulted from these additional methods. Several trials with an automated search/match system demonstrated the difficulties of analyses of such complex phase assemblages. The need for SEM characterization of the ashes to accompany the XRD analyses is discussed.
X-Ray Diffraction Analysis of NPK 12-19-19 Fertilizers
Authors: Knob B. , Waňková J. , Moudrý F. , Kuba M.
Published: January 2013

A quantitative X-ray diffraction method for the phase analysis of fertilizers of the NPK 12-19-19 type has been worked out together with a complex system of computer software. A bank of synthetic standards was employed in the solution of the problem. To reflect the real structure of the phases determined in fertilizers as against the structure of synthetic standards, intensity coefficients based on chemical analyses were assigned to individual phases in the bank of standards.
New Copper (II) — Rare Earth (III) Compounds I. Ternary Systems CuO-M2O3-TO2
Authors: Lambert U. , Eysel W.
Published: January 2013

Ternary systems CuO-M2O3-TO2 with T = Si, Ge and M3+ = Al, Ga, Fe, Cr, Bi and Y were investigated at 1000°C. Ternary compounds were found only for M3+ = Y. CuY2Ge2O8 is monoclinic with a = 9.477 Å, b = 15.005 Å, c = 8.030 Å and β = 147.50°; CuY2 Si4 O12 is monoclinic with a = 7.052 Å, b = 14.283 Å, c = 4.738 Å and β = 103.32°; CuY2Ge4O12 is triclinic with a = 7.185 Å, b = 7.949 Å, c = 4.910 Å, α = 86.83°, β = 102.70° and γ = 113.84°. The last two structures are closely related. The binary double oxide series Cu2Ln2O5 was reinvestigated.
JCPDS — International Centre for Diffraction Data Sample Preparation Methods in X-Ray Powder Diffraction
Authors: Jenkins R. , Fawcett T. G. , Smith D. K. , Visser J. W. , Morris M. C. , Frevel L. K.
Published: January 2013

The aim of any diffraction experiment is to obtain reproducible data of high accuracy and precision so that the data can be correctly interpreted and analyzed. Various methods of sample preparation have been devised so that reproducibility, precision and accuracy can be obtained. The success of a diffraction experiment will often depend on the correct choice of preparation method for the sample being analyzed and for the instrument being used in the analysis.

A diffraction pattern contains three types of useful information: the positions of the diffraction maxima, the peak intensities, and the intensity distribution as a function of diffraction angle. This information can be used to identify and quantify the contents of the sample, as well as to calculate the material's crystallite size and distribution, crystallinity, and stress and strain. The ideal preparation for a given experiment depends largely on information desired.
Powder Diffraction Data of Neodymium Hydroxynitrate Nd(OH)2(NO3).H2O
Authors: Louër D. , Deneuve F. , Herviou C. , Gourlaouen C.
Published: January 2013

The neodymium hydroxynitrate, Nd(OH)2(NO3).H2O, (PDF #37-1841) has been investigated by means of X-ray powder diffraction data. The unit cell dimensions were determined from diffractometer methods, using strictly monochromatized CuKα1 radiation, and evaluated by indexing programs. The monoclinic cell found was a = 19.381(4)Å, b = 3.884(1)Å, c = 6.291(1)Å, β = 96.43(2)°.
A Modified Gandolfi Camera with Improved Adjustment Facilities
Authors: Sussieck-Fornefeld C. , Schmetzer K.
Published: January 2013

Described is an improved Gandolfi camera which overcomes the disadvantages of the adjustment procedure of the conventional instrument. The basic principle of the new construction is the introduction into a camera of a complete goniometer head as sample holder with two 45° rotation axes. Particular advantages of the modified Gandolfi camera are a simple and time saving centering technique as well as convenient combination possibilities of powder and single crystal investigations.
Données Cristallographiques Sur Le Trioxalato-Chromate(III) D'Ammonium Trihydrate: (NH4)3 (Cr(C2O4)3)· 3H2O
Authors: Merrachi E. H. , Mentzen B. F. , Chassagneux F.
Published: January 2013

The trihydrated ammonium trioxalato-chromate(III) (NH4)3 (Cr(C2O4)3)·3H2O crystallizes in the triclinic system with:

.
Computer Program for Deconvoluting Powder Diffraction Spectra
Authors: Wiedemann K. E. , Unnam J. , Clark R. K.
Published: January 2013

A program is presented that removes broadening from X-ray diffraction spectra. An instrumental spectrum can be used to describe empirically the broadening to be removed, or a Gaussian, Cauchy, or Pearson-VII distribution can be used to analytically describe it. In either case, singlet or doublet forms can be generated. The program returns the deconvoluted spectrum, the reconstructed spectrum, and a sum-of-squares difference between the original and reconstructed spectra. Deconvolution is accomplished using a combination of least-squares, background, and smoothing criteria that minimizes the effect of random counting errors.
The “Hook Effect” of X-Ray Diffraction Peak Broadening of Multilayer Thin Films
Authors: Dengfa Liu , Yuming Wang
Published: January 2013

The “hook effect” observed in the Warren-Averbach analysis of X-ray diffraction peaks from multiple layer thin films of copper has been investigated theoretically and experimentally. The strengths of the “hook effect” for films of different layer thicknesses were analyzed. The results showed definite correlation between the strengths of the “hook effect” and the grain size distributions in 1, 4, and 19-layer copper films.
The Influence of Emulsifiers on the Crystal Properties of Tristearin and Trilaurin
Authors: Schlichter J. , Mayer I. , Sarig S. , Garti N.
Published: January 2013

The effect of solid emulsifiers, added at the level of 10%, on the lattice parameters of tristearin and trilaurin, has been studied by powder X-ray diffraction method. The presence of sorbitan monostearate and glycerol-l-stearate affects slightly the lattice constant a in tristearin; on the other hand, although sorbitan monostearate causes an increase in a of trilaurin, glycerol-l-stearate does not. The presence of sorbitan monolaurate and glycerol-l-laurate affect a of trilaurin similarly to the long chain emulsifiers.

A correlation between the effect on a and the increase in melting point has been found.

The presence of the emulsifier does not alter drastically the lattice dimensions of the fat. The slight dissimilarity in crystal structure between tristearin and trilaurin is confirmed by the diverse effects of the emulsifiers on the internal structure of the fat.
Données Cristallographiques sur le Trioxalato-Ferrate (III) d'Ammonium Trihydraté: (NH4)3(Fe(C2O4)3)·3H2O
Authors: Merrachi Par El Houssine , Chassagneux Fernand , Mentzen Bernard F.
Published: January 2013

The trihydrated ammonium trioxalato-ferrate (III) (NH4)3(Fe(C2O4)3)·3H2O cristallizes in the monoclinic system with:

The space group is P21/c[14].
Synthesis and Unit Cell Parameter Refinement of 25 Tungsten Bronze Ferroelectrics
Authors: Zellmer Lauren A. , Smith Deane K. , Nelson Diane , Scheetz Barry E.
Published: January 2013

Synthesis and unit cell parameter refinement of 25 ferroelectric compounds with the tungsten bronze structure are reported. A general chemical formula for these compounds is (A1, A2, C) B10 O30, where specifically A1 and A2 = K, Na, Ba, Sr, Pb, La, Eu, Sm, Y, Bi; C = Li; and B = Nb, Ta, Ti, W. All compounds were prepared by solid state sintering at temperatures ranging from 1100°C to 1380°C. Refined cell parameters (tetragonal with space group P4bm[100]), I/Icor values, calculated densities and Z values are included for the 25 compounds.
Fruits of Serendipity in Research of Titanium Compounds: from “Sodium Tianide” to Titanium Nitride Whiskers
Authors: Bamberger C. E.
Published: January 2013

The usefulness of complementing the results of X-ray diffraction (XRD) with an independent technique such as Raman spectroscopy (RS) was demonstrated by the successful identification of the products (TiN and Na-titanates) from the reaction of TiO2 with NaCN. The study of other reactions of NaCN with several Ti-compounds to produce TiN powder led to the development of new syntheses reactions for known [TiP2O7, NaTi2(PO4)3 and NaxTiO2] and for new [(TiO)2P2O7, Na(TiO)PO4 and Na4(TiO)(PO4)2] compounds. The reaction of NaxTiO2 with NaCN produced TiN in the form of whiskers.
X-Ray Powder Diffraction Data for Sodium Octyl Sulfate, Sodium Decyl Sulfate and Sodium Dodecyl Sulfate
Authors: Bittencourt D.R. Santos
Published: January 2013

Indexed X-ray diffraction powder data for three homologous amphiphiles, sodium octyl sulfate (SOS), CH3[CH2]7 OSO3Na, sodium decyl sulfate, CH3[CH2]9OSO3Na (SDS), and sodium dodecyl sulfate CH3[CH2]11OSO3Na (SLS), are reported. Probable space groups for the three compounds are monoclinic P2[3], Pm[6], or P2/m[10]. Refined cell parameters were determined from powder data obtained with a Guinier Camera. Powder data are compared to existing patterns, PDF 4-10 (SOS) and 4-6 (SLS).
Microabsorption Correction of X-Ray Intensities Diffracted by Multiphase Powder Specimens
Authors: Hermann H. , Ermrich M.
Published: January 2013

The absorption of X-rays in a heterogeneous material depends on the linear absorption coefficients and volume fractions of the components, and on die geometrical peculiarities of their distribution. The latter is called the microabsorption effect, it can be separated into a bulk and a surface contribution. Within the framework of a well-defined stochastic structure model, the bulk contribution to the microabsorption is calculated for arbitrary random multiphase systems in terms of dependence on volume fractions and mean chord lengths of particles. Expressions are derived which are suitable for eliminating the experimental errors of scattering intensities caused by the bulk contribution of microabsorption.

If only one wavelengtii of radiation is used, the mean chord lengths of the phases of the sample must be determined by other experimental techniques. A method is proposed to overcome this difficulty by using two or more wavelengths of radiation; this correction procedure works without the knowledge of the particle sizes of the phases.
Crystal Data for Nickel Cimetidine Chloride: Ni (CM)2 CL2·2H2O
Authors: Amigó J.M. , Ochando L.E. , Reventós M.M. , Sancho A. , Soto-Tuero L.
Published: January 2013

Nickel Cimetidine Chloride, Ni(C10H16SN6)2Cl2·2H2O has been investigated by means of X-ray powder diffraction. Unit cell dimensions were determined by indexing programs, from diffractometer data obtained with copper radiation. A primitive monoclinic cell was found: a = 11.836(3)Å, b = 13.322(5)Å, c = 10.487(2)Å, β = 113.08 (2)°, Z = 2, Dx = 1.462 g/cm3, M.W. = 670.32. These data are consistent with values reported in the literature for other cimetidine complexes.
Synthesis and cell refinement of Ba0.5+x/2Zr2P3−xSixO12 with x=0 and 0.175
Authors: Subramaniam Shanmugham , Stinton David P. , Cavin O. Burl , Hubbard Camden R. , Becher Paul F. , Limaye Santosh Y.
Published: January 2013

Ba0.5+x/2Zr2P3−xSixO12 or BaZPS compounds were synthesized by the sintering of powders formed by a solid-state reaction. The cell parameters of Ba0.5Zr2P3O12 and Ba0.5875Zr2P2.825Si0.175O12 were determined from X-ray diffraction (XRD) data based on the (#148) space group with hexagonal setting. The cell parameters were found to increase with increasing Si content in BaZPS.
A new method for Rietveld clay analysis. Part I. Use of a universal measured standard profile for Rietveld quantification of montmorillonites
Authors: Taylor J. C. , Matulis C. E.
Published: January 2013

A new method for the quantification of montmorillonite by full-profile Rietveld analysis of the XRD profile is presented. A measured standard XRD pattern of Algerian bentonite was used to construct a universally applicable montmorillonite (hkl) file for use with a P.C. based Rietveld XRD quantitative analysis system, SIROQUANT. “Universal” means that the standard file can be used for montmorillonites from other localities. The validity of the montmorillonite standard profile was tested with weighed mixtures of quartz and different standard montmorillonites. The results show the montmorillonite observed (hkl) file is generally applicable (i.e., universal), and can be used to quantify montmorillonite in any mineral without modification or chemical treatment of the sample. Two halfwidth functions were used for the montmorillonite, corresponding to the sharp (hk0) and broad (hkl) classes of reflections. A March preferred orientation parameter for montmorillonite was also refined.
Structures and X-ray diffraction patterns of compounds in the Sr–Nd–Cu–O system
Authors: Wong-Ng Winnie
Published: January 2013

A comprehensive review of phases found in the Sr–Nd–Cu–O system which contains the high Tc superconductor phase Sr1−xNdxCuO2 has been prepared. This paper summarizes the crystal structures reported in the literature and the X-ray powder diffraction patterns reported in the ICDD Powder Diffraction File (PDF). In order to supplement the PDF with new patterns, calculated X-ray powder diffraction patterns generated from reported structures are provided for five ternary oxides: Sr0.86Nd0.14CuO2, SrNdCuO3.5, Sr6Nd3Cu6O17, Sr2NdCu2O5.66, and Sr1.2Nd1.8Cu2O6.
Crystal data and X-ray powder-diffraction data for ferrimolybdite, Fe2(MoO4)36.8(H2O)
Authors: Horn Ernst , Kurahashi Masayasu , Huang Dianhao , Wu Chengyu
Published: January 2013

Powder-diffraction data were collected for a Chinese sample of ferrimolybdite. This mineral is orthorhombic, space group Pmmn or Pm21n, with a = 6.665(2), b = 15.423(5), c = 29.901(8), and V = 3074(1) Å3.
X-ray powder diffraction analysis of a nonlinear optical material 3-nitro–4-hydroxy–4′-bromobenzophenone
Authors: Jin Zong-ming , Jin Zheng , Zhou Xiang-yin
Published: January 2013

A nonlinear optical material 3-nitro–4-hydroxy–4′-bromobenzophenone has been characterized by x-ray powder diffraction. Experimental values of 2θ, corrected for systematic errors, relative peak intensities, values of d, and the Miller indices of 109 observed reflection with 2θ up to 90° are reported. The powder diffraction data have been evaluated, and the figures-of-merit are reported. The unit cell parameters least-squares refined from 34 nonoverlapping peaks of the orthorhombic compound with a P212121 space group are a = 7.619(7) Å, b = 27.651(5) Å, c = 5.650(7) Å, V = 1190.5(9) Å3, Z = 4, and Dx = 1.389 g/cm3.
X-ray powder diffraction analysis of NiZnCuSn ferrite containing antimony
Authors: Jin Zong-ming , Chen Ya-jie , Jin Zheng
Published: January 2013

Crystallographic data for Ni0.41Zn0.60Cu0.01Fe2.04−xSbxO4+δ (0.01≤x≤0.12) ferrites are significantly influenced by small additions of antimony. XRD analysis reveals that changes in crystal data for small Sb substitutions differ markedly from those for greater Sb substitutions. The differences are due to the contribution of the Sb ion. Complete crystal data for six solid solution compositions are reported. An X-ray powder diffraction pattern for Ni0.41Zn0.60Cu0.02Sn0.01Fe2.02Sb0.02O4+δ is given.
A method for obtaining the error of a peak position due to counting statistics
Authors: Hwang Bing H. , Tu S. F.
Published: January 2013

A method is described to determine the standard deviation of a peak position due to counting statistics. In this method, the statistical noise for a peak is first simulated based on the model of Poisson distribution and then imposed on the peak. The peak position is then determined by a profile fitting routine. By repeated application of these processes on a given peak, one obtains a number of slightly different peak positions and hence their corresponding standard deviation. This method can be applied to a peak described by any analytical function or a set of any number of digitized points. Investigation of the precision of peak positions was carried out by applying this method on various analytical peaks located at low, medium, and high 2θ angles. The results showed that the standard deviation of a peak position decreases with increasing P/B and P/σ, where P is the net peak count above the background B and σ=(P + B)½ is the estimated standard deviation for noise. It increases with increasing peak width and Δ2θ, the step size used to digitize the peak profiles. It decreases as the 2θ range of simulation and fitting increases up to 2θ=3 FWHMs (full width at half maximum) and remains at a constant value thereafter. The standard deviation of the position of a real peak obtained by ten repeated measurements is 0.0034°; the corresponding result obtained by the current method is 0.0035°. This peak is best fitted by a Pearson-VII function and the standard deviation obtained by this method is 0.013° when only the head portion with intensity ≥85% maximum net intensity is simulated and fitted. The corresponding result obtained by the traditional method of parabola fitting is 0.0055°. Therefore, the precision of a peak position also depends on the peak shape.
Structure of [Pd(NH3)4]Cr2O7
Authors: Laligant Y. , Le Bail A.
Published: January 2013

The structure of [Pd(NH3)4]Cr2O7has been determinedab initiofrom conventional X-Ray powder diffraction data by the Patterson method. The cell is monoclinic (space groupP21/c,Z= 4), witha= 7.771(3) Å,b=11.578(1) Å,c=11.852(4) Å, andβ= 105.50(4)°. Refinements of 57 parameters by the Rietveld method, using 852 reflections lead toRB= 0.032,RP= 0.075, andRwp= 0.092. The structure is built up from PdN4square planes linked to Cr2O7groups by hydrogen bonds. Hydrogen atoms could not be located.
Structure refinement and X-ray powder diffraction data for kalipyrochlore (K,Sr,Na,Ca,H2O)2−m(Nb,Ti)2−xO6−wY1−n, with (0<m<0.8, x∼0.2, W = 0 and 0.2<n<1)
Authors: Philippo S. , Naud J. , Declercq J. P. , Feneau-Dupont J.
Published: January 2013

The kalipyrochlore (K,Sr,Na,Ca,H2O)2−m(Nb,Ti)2−xO6−wY1−n, with (0<m<0.8, x∼0.2, w = 0 and 0.2<n<1) from Lueshe, Zaire is a defect pyrochlore species whose A-site weakly depleted. The measured powder diffraction is presented with a calculated figure of merit F(30) = 74.7(0.010,39). The structure has been refined by single-crystal from X-ray diffraction data collected on a Huber four-circle diffractometer and by Rietveld analysis from X-ray powder diffraction data. The slightly weathered crystal (studied by single crystal) has a cubic pyrochlore-type structure with the same atomic positions and a unit-cell parameter a = 10.603(5) Å, space group (S.G.): Fd3m. The highly weathered crystal (studied by Rietveld) has the same cubic pyrochlore-type structure except for the oxygen position. The oxygen moved from the 48f position with x, y, z equal to 0.284, 0, 0 to x = 0.308(5), y = 0.024(6) and z = –0.028(9). The cell parameter is a = 10.569(6)±0.0007 Å. These modifications of positions induce a distortion of the A-site into an hexagonal bipyramid and an elongation of the B-site along the c axis of the octahedron.
Rietveld refinement of the solid-solution series: (Cu,Mg)SO4·H2O
Authors: Lengauer C. L. , Giester G.
Published: January 2013

The kieserite-type solid-solution series of synthetic (Cu,Mg)SO4·H2O was investigated by TG-analysis and X-ray powder diffraction using the Rietveld method. Representatives with Cu≥20 mol% are triclinic distorted () analogous to the poitevinite (Cu,Fe)SO4·H2O compounds. Cation site ordering with preference of Cu for the more distorted M1 site was additionally proven by the structure refinement.
X-ray powder diffraction data for Ba2Cu3PrO6.96±0.01
Authors: Lamberti V. E. , Rodriguez M. A. , Navrotsky A.
Published: January 2013

The X-ray powder diffraction pattern for the title compound is reported in the range 5 ≤ 2θ ≤ 125°. The sample was prepared through solid-state reaction of BaCO3, CuO, and Pr6O11, and characterized with respect to oxygen content through iodometric titration. Refined parameters for the orthorhombic (space group Pmmm) unit cell are a = 3.8587(2) Å; b = 3.9302(1) Å; c= 11.7126(3) Å; a/b = 0.98181(6); a/c = 0.32945(2); b/c = 0.33555(1); Z = 1; Dx = 6.705(2) Mg m−3; V = 177.62(1) Å3; formula wt. = 717.48(16) g mol−1; SS/FOM: F30 = 48(0.005,127).
X-ray diffraction studies of solid solutions of Cr-, Mn-, Fe-, Co-, and Ni-containing transition metal spinel oxides
Authors: Allen G. C. , Hallam K. R. , Jutson J. A.
Published: January 2013

A wide range of transition metal oxide solid solutions have been prepared and characterised using powder X-ray diffraction (MnxCo1−xFe2O4, FexCo1−xFe2O4, NixCo1−xFe2O4, FeFexCr2−xO4, MnFexCr2−xO4, MnxFe1−xCr2O4, MnxFe1−xFe2O4, NixFe1−xFe2O4). Calibration curves have been obtained relating oxide composition to unit cell parameter or d spacing. From these curves it is possible to identify the composition of oxides formed on steel surfaces in varied industrial environments. Even when poor diffraction patterns are obtained and little sample is available, an estimate of composition can be made.
The early stages of crystallite growth of CeO2 obtained from a cerium oxide nitrate
Authors: Guillou N. , Auffrédic J. P. , Louër D.
Published: January 2013

An analysis of the microstructure of nanocrystalline cerium oxide produced by thermal decomposition of cerium (IV) oxide nitrate at temperatures in the range 230° to 960 °C is described. Parameters describing the breadths and shape of X-ray diffraction line profiles were obtained by means of pattern decomposition and a method based on the Voigt function was used to obtain information on the temperature dependence of the microstructure. No marked anisotropy in size and strain broadening was observed. It was found that the crystallites are on average spherical, the dimensions increasing significantly with formation temperature, while microstrains decrease with annealing temperature. The results of size determinations were compared with SEM measurements. They suggest a competition between the crystallite growth and “particle” growth processes in the initial sintering of the loosely packed cerium oxide powder.
Synthesis and characterization of high purity, single phase GaN powder
Authors: Balkas Cengiz M. , Basceri Cem , Davis Robert F.
Published: January 2013

Synthesis of high-purity, single-phase gallium nitride (GaN) powder has been achieved by reacting molten Ga with flowing ammonia (NH3) in a hot wall tube furnace. The optimum temperature, NH3 flow rate, and position of the boat in the hot wall tube furnace relative to the NH3 inlet for the complete reaction to pure GaN for our system were 975 °C, 400 standard cubic centimeters per minute (seem) and 50 cm, respectively. The X-ray diffraction (XRD) data revealed the GaN to be single phase with a = 3.1891 Å, c = 5.1855 Å, in space group P63mc, Z=2 and Dx =6.089 g cm−3. Scanning electron microscopy revealed a particle size distribution in the crushed material between 1 and 5 μm with most of the particles being ≍1 μm.
Specimen displacement error in focusing systems
Authors: Sperling Z.
Published: January 2013

The error is investigated which results from the employment of tangential approximation in the calculation of line shift caused by specimen displacement from the recording circle in focusing systems (Guinier, Seemann–Bohlin). After an exact expression has been deduced and compared with the approximate formula in a numerical example, it is concluded that the error caused by the approximate formula may be important only in exceptional cases. The deduced exact formula is also compared with that given by Rafaja and Valvoda [Powder Diffr. 6, 200–203 (1991)] with the conclusion that both formulas are mathematically equivalent and complementary with respect to the theoretical and measured values of the diffraction angle 2θ.
Powder data for potassium sodium silicate Na1.3K0.7Si2O5
Authors: Sakaguchi Mikio , Sakamoto Ichiro , Akagi Ryuichi , Toraya Hideo
Published: January 2013

X-ray powder diffraction data for a new potassium sodium silicate Na1.3K0.7Si2O5are reported. The sample was prepared by calcining a mixture of NaOH, KOH, and sodium silicate (SiO2/Na2O=3.54, moisture content=60%) at 873 K for 2 h. The crystallographic data obtained by using the whole-powder-pattern decomposition method are Na1.3K0.7Si2O5, monoclinic, P21/c, a=4.8426(1) Å,b= 8.6892(2) Å,c= 11.9686(3) Å,β=90.373(2)°,V=503.60(2) Å3,Z=4,Dx= 2.51 g/cm3.
Crystal structure of the three-dimensional magnetic network of type Mek[Fe(CN)6]l·mH2O, where Me=Cu, Ni, Co
Authors: Ratuszna A. , Juszczyka S. , Małecki G.
Published: January 2013

The crystal structures of Mek[Fe(CN)6];l·mH2O where Me = Cu, Ni and Co, have been refined from X-ray (CuKa) powder diffraction data by means of Rietveld analyses in space group . The Fe and Me ions are octahedrally coordinated by C and N atoms respectively, forming three-dimensional bimetallic networks with the CN-groups as bridging ligands. The Me(l) sites (k = 2, l=1) and the Fe sites (k = 3, l = 2) are partially occupied. Water oxygens were placed in alternative, empty metal sites.
Structures of Orthorhombic and Cubic Dicadmium Stannate by Rietveld Refinement
Authors: Bowden M.E. , Cardile C. M.
Published: January 2013

The structures of orthorhombic (a=5.5686(2)Å, b=9.8946 (2)Å, c=3.19369(12Å) and cubic (a=9.177(3)Å) Cd2SnO4were refined by Rietveld analysis of X-ray powder diffraction patterns. Both of these polymorphs were chemically treated with hydrogen gas mixtures at 400°C, resulting in a colour change from yellow to green. Small structural changes were observed for the orthorhombic material, which underwent a uniform contraction (≈0.02%) of cell size and movement of some oxygen atoms towards the tin atoms. Evidence for loss of structural oxygen was sought, but could not be found above the detection limit of 0.3%. Cubic Cd2SnO4possesses the spinel structure with a large (at least 65%) degree of inversion. Samples prepared with a smaller cell have so far proved unsuitable for Reitveld analysis.
Studies of Distortion in Potassium Manganese Fluoride, KMnF3, at 10°K: an Example of Powder Profile Analysis Using the Pearson Type VII Distribution
Authors: Ratuszna A. , Majewska K.
Published: January 2013

Pearson VII functions, some of the most useful descriptions of the intensity distribution within the X-ray powder reflection, have been used to study distortion in the perovskite-type structure of KMnF3. Separate full-widths, Δ, at half-maximum intensity, and Pearson exponents, m, were taken for the low- and high-angle sides of the profiles. The background was assumed to be linear. For the distorted structure, summation was made over all overlapping lines that might possibly contribute to the observed profile. Measurements were performed using a powder diffractometer with a specially adapted electronic system consisting of an automatic data recorder and a method, developed at this laboratory, for transferring data to an IBM PC/AT computer. By these means it could be shown that at 10° K the crystal structure of KMnF3distorts from cubic to monoclinic.
Préparation, Identification et Radiocristallographie d'un Hétérocycle Cétonique à Intérêt Médicinal: l'Isopropyl-3, phényl-2, diaza-1,3, one-5 bicyclo [3,3,0] octène-1
Authors: Caranoni Par Mme C. , Reboul M.J.P. , Soula Melle C.
Published: January 2013

The heterocycle of a functionalized 2-imidazoline, C15N2OH18, was obtained by reaction when 2-bromo, 2-alkenoïc ketone was allowed to react with a monosubstituted benzamidine. The compound presents a R*R* configuration. X-ray powder diffraction data have been obtained from single multifaceted brown crystals prepared at 273 K in benzene with triethylamine as catalyst. Chemical analysis gives a purity better than 99%. This compound crystallizes in the monoclinic space group P21/c [14]. The cell parameters were determined by employing single-crystal diffraction methods (Bragg and precession patterns) and were refined from accurate powder diffractometer data recorded at T = 293 (1) K.
Use of Rietveld Pattern Fitting to Determine the Weight Fraction of Crystalline Material in Natural Low Quartz Specimens
Authors: Jordan Bernard , O'Connor Brian H. , Deyu Li
Published: January 2013

Quantisation of low-quartz in crystalline mixtures has been performed by X-ray powder diffractometry (XRPD) for many years. Conventional methodology, using discrete-peak integrated intensities, is frequently performed employing calibrations prepared with natural low-quartz specimens. Previous research showed that from a conventional XRPD study of low-quartz specimens, the amorphous content of a suite of natural low-quartz specimens ranged from 1% to 28%. That study thereby underlined the importance in XRPD calibration of characterising the amorphous content (or its complementary quantity “weight fraction of crystalline material, WCFM” employed here). This paper describes an application of pattern-fitting Rietveld analysis for characterising the WCFM in a suite of low-quartz specimens. The results gave WCFM values ranging from 0.91 (esd, σ= 0.02) to 1.00(0.02) for six specimens for which the SiO2chemical content ≥ 99.5%.
Influence of Grinding Methods on the 101 X-Ray Powder Diffraction line of α-Quartz
Authors: Battaglia Stefano , Franzini Marco , Leoni Leonardo
Published: January 2013

The influence of grinding procedures on the intensity and full-width-half-maximum for the 101 line of the X-ray powder diffraction pattern for α-quartz has been investigated using samples of controlled grain size. Data collected on powders obtained by four dry grinding methods show substantial variations (up to 35%) in the quartz diffraction intensities. These variations are evident in the <5 μm size fractions and are attributed to the creation of different thickness of amorphous silica layers on quartz grains by grinding. This result suggests that optimum grinding conditions should be defined for quantitative X-ray diffraction analysis.
Powder Diffraction Data for Two Bivalent Metal Hydroxide Nitrates Cd5(OH)8(NO3)2·2H2O and Zn5(OH)8(NO3)2·2NH3
Authors: Bénard Patricia , Louër Daniel
Published: January 2013

Cadmium hydroxide nitrate dihydrate, Cd5(OH)8(NO3)2·2H2O, and zinc hydroxide nitrate diammoniac, Zn5(OH)8(NO3)2·2NH3, have been investigated by means of X-ray powder diffraction. Their unit cell dimensions were found by an indexing program and confirmed by single crystal studies. Precise data collected with strictly monochromatic radiation are reported. The figures of merit are F30=118 (0.0071,36) for the cadmium compound and F30=53 (0.015,38) for the zinc compound. A short discussion of the unit cell parameters compared to those of a related zinc hydroxide nitrate dihydrate is presented.
A Robust Method for Least Squares Lattice Parameter Refinement
Authors: Chen B.H. , Jacobson R.A.
Published: January 2013

A program has been written for rapid lattice parameter refinement which is designed to be applied to components in a mixture. This FORTRAN program employs a linear least-squares technique and is applicable to crystal systems with symmetry orthorhombic or higher. In addition to lattice parameters, a 2θ-zero can also be refined. Either approximate lattice parameters or a minimal set of indexed lines can be used as input. An example is given of its application to a AuMn two phase system.
Reliability of Commonly Used Versions of the Powder Diffraction File PDF-2
Authors: Drummond A. , Hay D.G.
Published: January 2013

Use of the program NBS*AIDS83 to modify data in the ICDD Powder Diffraction File (PDF) has led to substantial changes in card entries for Sets 1-33, in contrast to the previous policy of the International Centre for Diffraction Data of republishing cards where data has been significantly altered. Further changes to data have been revealed in the use of the database with the Philips PLUS 37 search and retrieval system.
Automatic Structure-Sensitive Searching in X-Ray Powder Diffraction
Authors: Kirik S.D. , Kovyazin S.A. , Fedotov A.M.
Published: January 2013

The resemblance between powder patterns because of similarity of crystal structures is well known and widely used. This phenomenon facilitates the determination of unit cells and is frequently used to predict crystal structures of new substances. At present the matching of diffraction analogues is done mainly by hand. Some approaches have been considered in this paper for applying a computer to the problem. Four numerical criteria for resemblance of powder patterns are suggested. Powder patterns are matched with patterns in a database by making use of a computer program based on these criteria.

The procedure results in a short list of powder patterns to be examined by the expert. The efficiency of the program is illustrated by examples of calculations for substances of both high and low symmetry. The search system may find an important application in X-ray powder diffraction analysis for the identification of solid solutions, of substances documented under unusual conditions, of structure analogues and for classification of patterns in a database.
An Electronic Driver for the Automatic Divergence Slit Attachment of Commercial Diffractometers
Authors: Anselmi-Tamburini Umberto , Lupotto Paolo , Spinolo Giorgio
Published: January 2013

The paper describes a stepping motor unit which can replace the mechanical connection between a goniometric circle (ϑ or 2ϑ) and the rotatory movement of the Automatic Divergence Slit attachment.
QPDA – A User-Friendly, Interactive Program for Quantitative Phase and Crystal Size/Strain Analysis of Powder Diffraction Data
Authors: Madsen I.C. , Hill R.J.
Published: January 2013

Recent developments in the Rietveld method for the analysis of powder diffraction data have seen the method evolve from its original purpose of crystal structure refinement to include the determination of phase abundance in polycrystalline mixtures and the estimation of crystal size and strain parameters. However, the Rietveld method is not easy to use and may deter many powder diffractionists, who are not interested in structure refinement per se, from using the method in its non-structural applications.

In order to overcome the difficulties in using the Rietveld method, a program, QPDA (for Quantitative Powder Diffraction Analysis), has been written that sets the conditions necessary for a single or multi-phase refinement, runs the Rietveld program and extracts phase abundance and size/strain information from the refined parameters. The program comprises a user-friendly, default-driven system of subroutines, written initially in VAX Fortran, and operates from a database of inorganic materials frequently encountered in a wide range of minerals and materials science industries.
Powder Diffraction Data for ZnGa2S4
Authors: Lowe-Ma Charlotte K.
Published: January 2013

Observed and calculated X-ray powder diffraction data are reported for ZnGa2S4. After corrections to the observed data, refined tetragonal unit cell parameters ao= 5.2779(2), co= 10.4179(8) Å (λ = 1.54051 Å) were obtained. The powder pattern for ZnGa2S4was calculated in space group Iwith a stoichiometric amount of Zn and Ga randomly distributed amongst the two cation sites.
A Study of Grazing Incidence Configurations and Their Effect on X-Ray Diffraction Data
Authors: Goehner Raymond P. , Eatough Michael O.
Published: January 2013

In recent years, grazing incidence angle attachments have been shown to be very useful in the phase identification of thin polycrystalline films. These devices are sold commercially as attachments to standard powder diffractometers. The attachment normally consists of a long soller slit assembly and a flat crystal monochromator. The soller slit with or without the monochromator is mounted on the diffracted beam side. In this paper we discuss the effects of different configurations from collimator to monochromator on diffraction data. An understanding of these effects is essential in order to obtain more reliable information on phase transformations, crystallite size, microstrain, and residual stress studies.
Crystal Data and Powder Diffraction Data for p-bromoiodobenzene at 293 K
Authors: Calvet M.T. , Alcobé X. , Tauler E. , Diarte M.A. Cuevas , Haget Y.
Published: January 2013

Crystal data for p-bromoiodobenzene (pBIB) at 293 K and a powder diffraction pattern are reported. The unit cell is monoclinic with S.G. = P21/a and Z = 2. The cell parameters are: a = 16.196(6) Å, b = 5.872 (3) Å, c = 4.233 (2) Å, β = 113.86 (2)°.
Crystal and Powder X-Ray Diffraction Data for TlBeXO4 (X = P, As)
Authors: Wallez G. , Elfakir A. , Quartern M.
Published: January 2013

Two new compounds TlBeXO4 (X = P, As) have been synthesized by solid state reaction. Single crystals were obtained. These compounds are isotypic, space group Pna21, Z = 4. Unit-cell parameters were determined. Powder diffraction data for each phase are reported.
Revised Crystal Data of Zr(MoO4)2, L.T. Form
Authors: Auray M. , Quarton M. , Tarte P.
Published: January 2013

Zr(MoO4)2 molybdate has been synthesized by solid state reaction. Single crystals were obtained by hydrothermal synthesis. Corrected crystal data are: monoclinic, a = 11.4309 (3), b = 7.9376 (2), c = 7.4619 (2) Å and β = 122.323 (2)°, V = 572.13 (6) /cm3 (5), Dx = 4.770 g/cm3. Powder diffraction data are reported.
Crystal Data for LnKFe (CN)6·4H20, Ln=La, Ce, Pr, and Nd Compound
Authors: Mullica D.F. , Sappenfield E.L.
Published: January 2013

Crystal data and a representative X-ray powder diffraction pattern are reported for a series of isomorphous compounds, LnKFe(CN)6.4H2O where Ln = La, Ce, Pr and Nd. They crystallize in the hexagonal space group P63/m (176) with Z = 2. A plot of the unit cell volume (V) versus the cube of the Ln ionic radius (r3) yields linearity with a correlation coeficient of 0.9998.
Standard X-Ray Diffraction Powder Patterns of Fifteen Ceramic Phases
Authors: Wong-Ng Winnie , McMurdie Howard F. , Paretzkin Boris , Kuchinski M.A. , Dragoo Alan L.
Published: January 2013

Fifteen reference patterns of oxide ceramics are reported. Included in the fifteen reference patterns are data for nine high critical temperature superconducting oxide and related phases Ba2Cu3ErO7, Ba3.2Cu1.7Er0.8O6.1·xCO2, Ba2Cu3HoO7, Ba2Cu3(Pr0.5Y0.5)O7, Ba3Dy4O9, Ba3Yb4O9, (Ba0.6Sr0.4)2Cu3YO7, (Ba0.8Sr0.2)2Cu3YO7, and CuNd2O4. The general methods of producing diese X-ray powder diffraction reference patterns were described previously in this journal (Vol. 1, No. 1, pg. 40 (1986)). The symbols used in diis article are defined in the PDF cards.
The Determination of Direction-Dependent Crystallite Size and Strain by X-Ray Whole-Powder-Pattern Fitting
Authors: Toraya H.
Published: January 2013

The procedure of whole-powder-pattern fitting without reference to a structural model has been applied to the determination of direction-dependent crystallite size and strain. The fitting function used is defined as the sum of (1) background intensity and (2) contributions from individual reflections given as the convolution of the observed instrumental function with the true data function in analytical form. Crystallite size and strain parameters are adjustable, together with unit-cell parameters and the integrated intensities of all reflections, during the whole-powder-pattern fitting. The procedure requires neither structural parameters nor intensity correction for preferred orientation in calculating profile intensity. The two models are incorporated for line broadening, one for isotropic size and strain effects and the other for the anisotropic size effect of cylindrical shape. The procedure has been tested for these two models using the observed data of 4 mole % Y2O3-doped tetragonal ZrO2 and hydroxyapatite, Ca5(PO4)3OH, respectively, and been shown to be effective for determining crystallite size and strain from the powder pattern with a relatively high peak density.
Comparison of a Solid-State Si Detector to a Conventional Scintillation Detector-Monochromator System in X-Ray Powder Diffraction Analysis
Authors: Bish David L. , Chipera Steve J.
Published: January 2013

A new Peltier-cooled solid-state Si(Li) detector has been compared to a traditional scintillation detector/diffracted-beam graphite monochromator system in conventional X-ray powder diffraction applications. Parameters studied included absolute count rates, detector linearity, peak-to-background ratios, detection limits, fluorescent radiation elimination, and peak profile shapes. Comparisons were performed on a Siemens D-500 θ-2θ diffractometer using constant sample and nondetector instrumental parameters. Advantages of the Si(Li) detector include a significantly increased count rate (3.4 - 3.8 times), primarily due to the elimination of the graphite monochromator, slightly lower background count rates, and the ability to change the analysis energy quickly. The higher count rate and slightly lower background count rate of the Si(Li) detector allow collection of data more rapidly than possible with a scintillation detector/diffracted-beam monochromator system and yield improved peak-to-background ratios and detection limits. Significant disadvantages of the Si(Li) detector include pronounced deviation from linearity at low count rates, making accurate measurement of even moderate countrate peaks difficult, and detector shutdown due to 100% deadtime between 4 and 5 × 10 4 counts/s (cps). The Si(Li) detector and the scintillation detector/diffracted-beam monochromator system are comparable in terms of fluorescence radiation elimination, resolution, and peak shape, although it appears tfiat die diffracted-beam monochromator measurably reduces the low-angle portion of the half width of all reflections.
X-Ray Powder Data for Tetracycline-urea Tetrahydrate, C23H36N4O13 and Tetracycline Hexahydrate, C22H24N2O8·6H2O
Authors: Blanchard Frank N. , Palenik Gus J.
Published: January 2013

Indexed powder diffraction patterns and related crystallographic data are reported for tetracycline-urea tetrahydrate and tetracycline hexahydrate, neither of which is represented in the X-ray Powder Diffraction File. Objective evaluation of the data indicates high precision of d-spacings and unit-cell parameters, intensities that are acceptably reproducible, sensitivity for low intensity reflections, good resolution of closely spaced reflections, and close correspondence with calculated patterns.
Solving the Crystal Structure of Cd5(OH)8(NO3)2·2H2O from Powder Diffraction Data. A Comparison with Single Crystal Data
Authors: Bénard Patricia , Louër Michèle , Louër Daniel
Published: January 2013

A comparison between the results of ab initio structure determination from X-ray powder diffraction data of a new cadmium hydroxide nitrate, Cd5(OH)8 (NO3)2·2H2O (SG C2/m), and those obtained from single crystal data is presented. The powder diffraction pattern has been analysed by an indexing method and fitting techniques. A total of 119 unambiguously indexed reflections has been extracted and used in subsequent treatment. The power of powder techniques to index the pattern and to find the structure model by normal Patterson and Fourier methods is clearly shown. The refinement of approximate coordinates has been carried out by the Rietveld method (444 reflections). The comparison of results with those obtained from single crystal data (2218 reflections) shows that the precision of positional parameter values is lower by a factor of 10, on average, in the powder study. These results are discussed in terms of crystallographic parameters (number of reflections used, number of parameters to refine, contrast between atoms) and, also, in terms of sample dependent properties (preferred orientation effect, impurity). Finally, the crystal structure has been derived from powder data with a precision probably sufficient for most purposes.