bluuebunny/crossref_metadata_2025 huggingface dataset:
JCPDS—International Centre for Diffraction Data round robin study of silver behenate. A possible low-angle X-ray diffraction calibration standard
Authors: Blanton T. N. , Huang T. C. , Toraya H. , Hubbard C. R. , Robie S. B. , Louër D. , Göbel H. E. , Will G. , Gilles R. , Raftery T.
Published: January 2013

A task group of the JCPDS—International Center for Diffraction Data (ICDD) was established with the charge of investigating the use of silver behenate, CH3(CH2)20COO·Ag, as a possible low-angle calibration standard for powder diffraction applications. Utilizing several data collection and analysis techniques, long-period spacing (d001) values with a range of 58.219–58.480 Å were obtained. Using the same collected data and one data analysis refinement calculation method resulted in dm values with a range of 58.303–58.425 Å. Data collected using a silicon internal standard and the same singular data analysis calculation method provided d001 values with a range of 58.363–58.381 Å.
Powder diffraction data of three 10,11-dihydro-5H-dibenz[b,f]azepine antidepressant drugs
Authors: Bandoli G. , Ongaro A. , Rubello A. , Tonus V. , Volpe G.
Published: January 2013

Space group and unit-cell parameters for three 10,11-dihydro-5H-dibenz[b,f]azepine antidepressant drugs were determined. Indexed powder diffraction data for each drug are reported.
Indexing crystal faces
Authors: Prigodich R. V. , Zager M.
Published: January 2013

This paper describes a straightforward method for the identification of the Miller indices associated with the face of a crystal of low symmetry. The method relies on orienting a crystal face parallel to the sample holder in the goniometer of a powder diffractometer. An intense diffractogram resulting from a single family of lattice planes parallel to the crystal face is obtained. The application of silicon powder to the surface of the crystal provides a means to correct 2Θ values for any misalignment of the crystal face. Calculated 2Θ and intensity values are used to assign the reflections from the corrected single-crystal diffractogram to a particular set of related lattice planes. In this paper are listed the corrected experimental 2Θ and intensity values for a particular face of a large single crystal of monoclinic hydroxylapatite and the theoretical 2Θ and intensity values for theh00 set of planes. Comparison of these parameters leads to the unambiguous assignment of that particular crystal face to theh00 Miller index.
The optimum standard specimen for X-ray diffraction line-profile analysis
Authors: van Berkum J. G. M. , Sprong G. J. M. , de Keijser Th. H. , Delhez R. , Sonneveld E. J.
Published: January 2013

A perfect general purpose standard specimen for high accuracy line-profile analysis is shown to be an illusion. Balancing the partly contradictory requirements, an optimum standard specimen for a parafocusing diffractometer is developed. To obtain the optimum standard specimen, a 5–10 μm particle size fraction is taken from the NIST certified Si powder SRM640a, about 1.5 mg/cm2 of this powder is uniformly deposited on a (510) oriented Si single-crystal wafer and the assembly is heat treated for 2 h at 1273 K to remove lattice imperfections. All procedures necessary are precisely given, easily applicable, and reproducing. For the present standard specimens, the random errors due to crystal statistics are quantified and shown to be acceptable for spinning specimens; the systematic errors due to residual size and transparency broadening are determined semi-empirically and can be eliminated, if desired. Thus the proposed optimum standard specimen allows the determination of instrumental line profiles free from systematic errors and with random errors in the line width of the order of 0.001 °2θ, allowing a full use of the capacities of modern diffractometers and data evaluation procedures.
X-ray powder diffraction data for ammonium nickel phosphate monohydrate
Authors: Guerra-López J. , Gómez A. , Pomés R. , González R.
Published: January 2013

Ammonium nickel phosphate monohydrate (NH4NiPO4·H2O) crystal data were obtained by X-ray powder diffraction. Ammonium nickel phosphate monohydrate is orthorhombic with unit-cell parameters a = 5.566 (1) Å, b = 8.760 (2) Å, and c = 4.742 (1) Å.
High temperature X-ray diffraction studies of the decomposition mechanism of YBa2Cu3O7−δ at an oxygen partial pressure less than 10 Pa
Authors: Pitschke W. , Bieger W. , Krabbes G. , Wiesner U.
Published: January 2013

The crystallographic data of YBa2Cu3O7−δ, Y2BaCuO5, BaCu2O2, and YBa4Cu3O9 at high temperatures and p(O2)<10 Pa have been derived on the basis of HT-XRD measurements. Whereas Y2BaCuO5 expands nearly isotropically, YBa2Cu3O7−δ and BaCu2O2 show anisotropic expansions. Furthermore, the first decomposition step of the considered compounds at p(O2)<10 Pa was observed. BaCu2O2 melts congruently at T ≍ 1273 K and Y2BaCuO5 decomposes via a peritectic reaction into Y2O3, Y2BaO4 and melts at T ≍ 1323 K. A solid-state reaction into Y2BaCuO5 and BaCu2O2 was indicated for YBa2Cu3O7−δ at T ≍ 1123 K. Because YBa4Cu3O9 becomes unstable at T ≍ 1123 K, this compound cannot be formed by the primary decomposition reaction of YBa2Cu3O7−δ
Carbonate-cancrinite: In-situ real-time thermal processes studied by means of energy-dispersive X-ray powder-diffractometry
Authors: Ballirano P. , Maras A. , Caminiti R. , Sadun C.
Published: January 2013

New powder X-ray data for cancrinite [ideally Na8Si6Al6O24 (CO3)2·2 H2O] are reported along with in-situ real-time thermal processes recorded using energy dispersive X-ray diffractometry (EDXD). A completely anhydrous phase is obtained after heating the sample up to 600 °C and quickly cooling it to room temperature, as shown by means of both Rietveld analysis and IR spectroscopy. The anhydrous phase does not show any tendency to re-acquire molecular water. During the heating process, at around 450 °C, a peak splitting is observed, possibly due to a reversible phase transition.
A semi-empirical asymmetry function for X-ray diffraction peak profiles
Authors: Riello P. , Canton P. , Fagherazzi G.
Published: January 2013

A new semi-empirical approximation for the asymmetry function to be used in the X-ray Rietveld analysis has resulted in lower values of the so-called goodness-of-fit index, defined asS = Rwp/Rexp, whereRwpis theR-weighted pattern andRexpis theR-expected [R. A. Young,The Rietveld Method(Oxford U.P., Oxford, 1993)], with respect to the corresponding values obtained with the classical approximation used by Rietveld in his fundamental paper. A comparing test of the two asymmetry functions was carried out for the cubic Y2O3and forαAl2O3using either pseudo-Voigt or Pearson VII symmetrical functions and two diffractometers. As in the case of the Rietveld approximation, the present one, which employs an exponential function, is optimized using only one fitting parameter. Experimentally, the asymmetry can be considerably diminished by using Soller slits with a small opening angle (≤2°).
Powder diffraction data for copper hexafluorides: Ba2CuF6 and Pb2CuF6
Authors: Samouël Maurice , Gredin Patrick , de Kozak Ariel
Published: January 2013

Based on the crystal structure determination of orthorhombic Ba2CuF6 (space group Cmca), the previous X-ray powder patterns given for Ba2CuF6 (PDF 21-809) and Pb2CuF6 (PDF 22-654) are reindexed.
X-ray powder diffraction data for the identification of boracite-group minerals
Authors: Burns Peter C.
Published: January 2013

An X-ray powder-diffraction pattern for boracite, Mg3B7O13Cl, is reported. Boracite is orthorhombic, space group Pca21, and the refined unit-cell parameters are a=8.557(6), b=8.553(8), c= 12.09(1) Å. X-ray powder-diffraction patterns have been calculated for the boracite-group minerals boracite, ericaite, trembathite and congolite. The calculated pattern for boracite is in good agreement with the observed pattern reported here, but the PDF entry (5-710) for boracite is missing several intense peaks. The calculated pattern for ericaite is in poor agreement with the PDF entry (29-697) for ericaite, and PDF 29-697 is for congolite, not ericaite. The calculated powder patterns presented here for these four minerals will facilitate their identification via X-ray powder diffraction. © 1995 International Centre for Diffraction Data.
Synthesis and cell refinement for icosahedral boron phosphide B12P2
Authors: Yang P. , Aselage T. L.
Published: January 2013

Icosahedral boron phosphide (B12P2) was directly synthesized from elemental powders by a high-temperature reaction under an argon pressure. Powder diffraction data were collected for two B12P2 samples, and diffraction patterns were compared with calculated patterns of phosphorus deficient crystals: B12+xP2−x for 0<;x<0.2. The as-synthesized B12P2 appears to be close to its ideal stoichiometry based on the consistency between the observed and the calculated values of the relative intensity for all diffraction planes below 90° 2θ.
Powder-diffraction data for several solid solutions with the compositions (CaxSr1−x)CuO2 and (CaxSr1−x)2CuO3
Authors: Misture S. T. , Park C. , Snyder R. L. , Jobst B. , Seebacher B.
Published: January 2013

Several compositions of the solid solutions (CaxSr1−x)CuO2 and (CaxSr1−x)2CuO3, both of which are found as minor phases in the high-temperature superconductors, were prepared by solid-state reaction. X-ray powder-diffraction patterns for three compositions of (CaxSr1−x)CuO2 and two for (CaxSr1−x)2CuO3 are presented.
Crystal Chemistry and Phase Equilibria Studies of the BaO(BaCO3)−½R2O3-CuO Systems III: X-Ray Powder Characterization and Diffraction Patterns of Ba3R3Cu6O14+x, R = Lanthanides
Authors: Wong-Ng W. , Chiang C.K. , Paretzkin B. , Fuller E.R.
Published: January 2013

The superconductor related phases Ba3R3Cu6O14+x(or Ba2−zR1+zCu3O7+x, with z=0.5), where R = Pr, Nd, Sm, and Eu, have been prepared and characterized by X-ray powder diffraction, ac magnetic susceptibility measurement, resistivity measurement and thermogravimetric analysis (TGA). Attempts to make corresponding compounds with R = Gd, Dy, Y, Er, and Lu were not successful; they do not appear to form for rare-earth elements, R, with an ionic size smaller than Eu. The oxygen content of the successful materials was estimated by TGA. The Ba3R3Cu6Cu14+xcompounds which were sintered at 950°C and annealed in oxygen at 550°C were found to be nonsuperconducting above 10K. Previously reported results for the R=La compound have indicated that it was superconducting with a transition temperature of 15K The oxidation-reduction behavior of the Ba3R3Cu6O14+xmaterials is similar to that of the superconductor phases Ba2RCu3O6+x.

These present isostructural compounds are tetragonal with a space group of P4/mmm. The cell parameters range from a = 3.8612(4), c = 11.5624(14) Å, V = 172.38(4) Å3in the Eu compound to a = 3.8893(3), c = 11.6370(11) Å, and V = 176.03(3) Å3in the Pr compound. The standard X-ray diffraction patterns of these materials are given.
The Efficiency of the Numerical Search Manual with Respect to the Number of Entries per Phase
Authors: Bayliss Peter
Published: January 2013

With the Powder Diffraction File (1988), twelve different numerical search manuals with the number of entries per phase from one to four were used to identify the 237 experimental X-ray powder diffraction data sets collected from visually measured 57.3 mm diameter Debye-Scherrer films. Eighty-four percent of the experimental X-ray powder diffraction data have the same strongest reflection as the data in the Powder Diffraction File. For a single-phase unknown the most efficient numerical search manual type is a single entry per phase if used correctly and systematically; however, multiple entries do help in some instances. Up to seven groups must be searched in a single-entry numerical search manual to identify a phase.
The Normal Paraffins Revisited
Authors: Heyding R. D. , Russell K. E. , Varty T. L. , St-Cyr D.
Published: January 2013

The low temperature modifications of the normal paraffins n-CnH2n+2crystallize in three groups (Broadhurst, 1962). The structure is triclinic for n even, 6 < n < 26 (Muller and Lonsdale, 1948; Nyburg and Luth, 1972); orthorhombic for n odd, 11 < n < 39 (Smith, 1953; Teare, 1959); and monoclinic for n even, 28 < n < 36 (Shearer and Vand, 1956). In all of these structures the hydrocarbon chains are linear and in trans configuration. The chains are parallel to one another, the terminal methyl groups forming the surfaces of lamella which are more or less perpendicular to the chain axis. For n < ca.36, it is apparently the interlamellar interaction between end methyl groups which dictates the symmetry. For longer chains the structure is usually orthorhombic and comparable to the structure of highly crystalline polyethylenes. Chains do not fold (as they undoubtedly do in polyethylenes) unless n is greater than 102 (Bidd and Whiting, 1985; Ungar and Keller, 1986).

The several crystal forms differ in the manner in which the nearest neighbor chains are related to one another. In the triclinic lattices the packing is such that a triclinic sublattice containing one methylene group is evident. In the other modifications the sublattice is orthorhombic and contains four methylene groups. If the overall symmetry is orthorhombic the long chain axes are perpendicular to the interlamellar surface; the x and y translations, perpendicular to the long axis, are common to both cells. If the nearest neighbor chains are displaced by two or four methylene groups along the chain axis, overall monoclinic symmetry results (Sullivan and Weeks (1970)).
A Method for Quantitative Phase Analysis of Silicon Nitride by X-Ray Diffraction
Authors: Devlin David J. , Amin Kamal E.
Published: January 2013

The relative intensities ratios for the determination of the relative amounts of alpha and beta phases in silicon nitride and the relative amounts of delta yttrium disilicate (Y2Si2O7) and nitrogen apatite [Y5(SiO4)3N] are reported. These constants were determined using an iterative method applicable when the pure phases are not easily prepared. In addition, a calibration curve was obtained for the quantitative measurement of free silicon in silicon nitride over the range 0 to 0.3% by weight of Si.
Rietveld Structure Refinement of Metastable Lithium Disilicate Using Synchrotron X-Ray Powder Diffraction Data From the Daresbury SRS 8.3 Diffractometer
Authors: Smith R.I. , West A.R. , Abrahams I. , Bruce P.G.
Published: January 2013

The crystal structure of metastable Li2Si2O5, Fw = 150.05, has been refined by the Rietveld method using high resolution X-ray powder diffraction data recorded at the Daresbury Synchrotron Radiation Source on the new 8.3 diffractometer. Li2Si2O5, in keeping with many compounds of interest to the materials scientist, exhibits relatively broad diffraction peaks. It is important to establish the quality of crystal structure data that may be obtained from such materials on this new instrument. Various functions were used to model the peak shape from this instrument; a split-Pearson VII function appeared to be marginally superior to Pearson VII or Pseudo-Voigt functions. Refinement was carried out using the split-Pearson VII in the space group Pbcn (60) and terminated with a = 5.6871(6), b = 4.7846(5), c = 14.645(1) Å, V = 398.50 Å3, Z=4, Dc= 2.502 gcm−3, Rwp = 17.06, Rex = 14.48 and Χ2 = 1.39. The refined parameters are compared with those obtained from a previous single crystal X-ray determination.
X-Ray Peak Intensities for the Binary Compound Al3Ti
Authors: Kumar K.S.
Published: January 2013

Powders of Al and Ti were blended and compacted, the compact then melted in an attempt to produce single phase Al3Ti. Optical microscopy of the cast and homogenized specimen revealed an almost single phase microstructure with minor amounts of a second phase. The composition of the matrix was measured using fully quantitative energy dispersive X-ray analysis. By use of X-ray diffractometry, the interplanar spacings and the associated integrated peak intensities were experimentally measured for the binary DO22 compound, Al3Ti. Using standard structure factor equations, the intensities were calculated for the various reflections. Good agreement was obtained between calculated and observed intensities.
Powder Diffraction Data of CdTexSe1-xSolid Solutions
Authors: Razik N.A. , Al-Barakati G. , Al-Heneti S.
Published: January 2013

CdTexSe1-xsolid solutions with (x) ranging between zero and one were prepared by solid state diffusion under vacuum and their precise lattice constants and X-ray powder diffraction data were determined. It was found that alloys with 0≤x≤0.4 possess the hexagonal wurtzite structure while those with 0.5≤x≤1.0 have the cubic zincblende structure. The lattice parameters obeyed Vegard's law according to the following formulae

Extrapolated lattice constants were a = 6.066(6) Å for the cubic form of CdSe and a = 4.563(6) Å and c = 7.502 (10) Å for the hexagonal form of CdTe.
X-Ray and Optical Data for Alkali Cation-Deficient Schorls from Jack Creek, Montana, U.S.A. and Ben Lomond, North Queensland, Australia
Authors: Foit Franklin F.
Published: January 2013

X-ray powder diffraction and optical data are presented for alkali-deficient schorls from two tourmaline-dumortierite deposits. The compositions of both schorls reflect the presence of an alkali-defect substitution, whereby the alkali cation deficiencies in the crystal structure are charge balanced by trivalent for divalent cation substitutions in the octahedral sites. Refined unit cell and optical data are as follows: a = 15.9523(15), c = 7.1466(2) Å, F30 = 104(0.009, 32), M20= 68, ε = 1.638(2), ω = 1.660(2), Dx= 3.12 for the schorl from Jack Creek, near Basin, Montana, U.S.A. and a = 15.9800 (15), c = 7.1504(2) Å, F30= 156(0.006, 32), M20= 152, ε = 1.642(2), ω = 1.668(2), Dx= 3.17 for the schorl from Ben Lomond, Hervey Range, North Queensland, Australia. Indexed X-ray powder diffraction patterns are also presented.
X-Ray Powder Diffraction Data for AITh2(VO4)3Compounds with AI= Li, Na, Ag
Authors: Elfakir A. , Souron J.P. , Quarton M.
Published: January 2013

Three orthovanadates ATh2(VO4)3with A = Li, Na, Ag have been synthesized by solid state reaction. Single crystals of AgTh2(VO4)3were obtained. This compound is isotypic with sheelite whose space group is I41/a(88). The two other compounds (A = Li, Na) have a zircon type structure: I41/ amd(141). Unit-cell parameters and powder diffraction data for the three compounds are reported.
X-Ray Powder Diffraction Data of Bi2Mo3O12·nH2O (n = 4.75)
Authors: Murakami Yasushi , Ishizawa Nobuo , Imai Hisao
Published: January 2013

X-ray powder diffraction data for Bi2Mo3O12·nH2O (n = 4.75) were obtained. The crystal system was determined to be monoclinic with space group P21or P21/m. The unit cell parameters were refined to a = 6.334(2) Å, b = 11.593(2) Å, c = 5.777(2) Å, and β= 113.166(8)°.
Powder Diffraction Data for the Imperfect Pyrochlore Terbium Titanate, Tb2Ti2O7
Authors: van de Velde G.M.H. , Lippens B.C. , Korf S.J. , Boeijsma J.
Published: January 2013

Notwithstanding expectations of a pure pyrochlore structure (cubic space group Fd3m (227) with Z=8) terbium titanate turns out, like many pyrochlore compounds, to be slightly disordered in the cation and the oxygen lattice so that it partially (for 10%) resembles a structure with fluorite properties (space group Fm3m (225) with Z = 2).
Intermediate Phases Produced During the Formation of Cadmium-Nickel Ferrites
Authors: Wolska Emilia , Riedel Erwin
Published: January 2013

X-ray powder diffraction analysis of samples obtained by thermal treatment of coprecipitated amorphous xCd(II) (1-x)Ni(II)2Fe(III)-hydroxides reveals that intermediate crystalline spinel species with lattice constants less than those for the nominal composition are formed before the designated cadmium-nickel ferrites, CdxNil-xFe2O4, come into existence.
A New Method Of X-Ray Crystal Analysis
Authors: Hull A. W.
Published: January 2013

The beautiful methods of crystal analysis that have been developed by Laue and the Braggs are applicable only to individual crystals of appreciable size, reasonably free from twinning and distortion, and sufficiently developed to allow the determination of the direction of their axes. For the majority of substances, especially the elementary ones, such crystals cannot be found in nature or in ordinary technical products, and their growth is difficult and time-consuming.

The method described below is a modification of the Bragg method, and is applicable to all crystalline substances. The quantity of material required is preferably 0.005 c.c., but one tenth of this amount is sufficient. Extreme purity of material is not required, and a large admixture of (uncombined) foreign material, twenty or even fifty per cent, is allowable provided it is amorphous or of known crystalline structure.
X-Ray Powder Diffraction Data for Complexes of Glucose Monohydrate with Sodium Bromide and Sodium Iodide
Authors: Rendle D.F. , Glazier E.J.
Published: January 2013

X-ray powder diffraction data for the complexes of glucose monohydrate with sodium bromide (C6H12O6. ½NaBr·½H2O) and sodium iodide (C6H12O6·NaI·½H2O) are reported. The crystals of both complexes are trigonal with space group P31 (No. 144). The complex with sodium bromide has a = 16.4338 (6), c = 17.623 (1)Å, V = 4121.9 Å3, Z = 18 and Dx = 1.745 cm−3. The sodium iodide complex has a = 16.5249(6), c = 17.882(1) Å, V = 4228.8 Å3, Z = 18 and Dx = 1.867 g cm−3. The Smith-Snyder FN values for these data are F30 = 59.4(0.0097,52) for the sodium bromide complex and F30 = 82.7(0.0098,37) for the sodium iodide complex.
X-Ray Powder Diffraction Characterization of BaR2CuO5 (R=Yttrium and the Lanthanides) and Related Compounds
Authors: Wong-Ng W. , Kuchinski M.A. , McMurdie H.F. , Paretzkin B.
Published: January 2013

A series of BaO:RxOy:CuO materials has been prepared where R=Y, La, Ce, Pr, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu. They have been characterized by X-ray powder diffraction methods. All BaR2CuO5 phases, commonly referred to as the “green phases”, are orthorhombic with space group Pbnm(62) and are isostructural. These single phase materials could be prepared with most lanthanides, except for La, Ce, Pr, Nd and Tb. Possible reasons for the exceptions are discussed. Both La and Nd tend to form a brown solid solution of Ba2+2xR4-2xCu2-xO10-2x with a tetragonal space group of P4/mbm(127). The major phases found in the Ce, Pr and Tb compositions are the perovskite-related structures BaRO3, and in the Pr case, Ba2PrCu3O6+x as well. The cell parameters of the green phase materials increase progressively from the Lu compound to the Sm compound: a ranges from 7.0506(6) to 7.2754(4) Å, b from 12. 0534(8) to 12. 4029(7) Å, c from 5.6099(5) to 5. 7602(3) Å, and the cell volume from 476.75(6) to 519.78(4) Å3. A correlation of the crystallographic data with the size of the R elements is given.
Unit-Cell Dimensions of Two-Dimensionai Clay Minerals
Authors: Bayliss Peter
Published: January 2013

The unit cell dimensions of minerals in the smectite group, regular and random mixed-layer groups, and halloysite shown in theMineral Powder Diffraction File(1986) have been refined by least-squares analysis in the hexagonal system with a primitive lattice with indices restricted tohkor 00lreflections. Trioctahedral minerals have largeraunit-cell dimensions than dioctahedral minerals.
X-Ray Powder Data for Two Tetracyclines: 6-Methylene-5-Hydroxytetracycline Hydrochloride (Methacycline Hydrochloride), C22H23N2O8Cl, and 6-Demethyl-7-Chlorotetracycline Hydrochloride Trihydrate (Declomycin Hydrochloride), C21H28O11N2Cl2
Authors: Blanchard Frank N. , Palenik Gus J.
Published: January 2013

Observed powder diffraction data for two tetracyclines were interpreted with the aid of calculated patterns based upon the crystal structures determined from a single crystal of the same batch for each compound. The results consist of high quality standard powder patterns with the usual supporting data.
The Crystal Structure of BaY2O4, Isotypic with SrY2O4
Authors: Costa G.A. , Ferretti M. , Fornasini M.L. , Franceschi E.A. , Olcese G.L.
Published: January 2013

Since the discovery of the superconductivity in Ba2YCu3 O7-x, the system Ba-Y-Cu-O has generated vast interest. The presence and the properties of the intermediate phases were examined, and the existence of the BaY2O4 phase was confirmed.

We have determined the crystal structure of this material from powder data; it is orthorhombic, Pnma (no 62) with a = 10.394(3) Å, b = 3.450(1) Å, c = 12.113(4) Å, isotypic with SrY2O4 (CaFe2O4-type). The observed and calculated intensity values are reported together with the powder diffraction data, obtained both by Guinier and diffractometer methods.
Crystal Data for Thirteen Tellurates MIBaNbTe2O9 (MI = Li,Na,K,Rb,Ag) and BaNbTe2O9 (MII = Mg,Ca,Sr,Ba,Cu,Zn,Cd,Pb)
Authors: Launay S. , Mahé P. , Quarton M.
Published: January 2013

Thirteen isotypic tellurates having the stoichiometries MIBaNbTe2O9 and BaNbTe2O9, with MI = Li,Na,K,Rb,Ag and MII = Mg,Ca,Sr,Ba,Cu,Zn,Cd,Pb, have been synthesized by solid state reaction. Single crystals of KBaNbTe2O9 were obtained. The compounds crystallize in the orthorhombic space group P212121 [19]. Unit-cell parameters for the 13 compounds and powder diffraction patterns for three representative compounds, KBaNbTe2O9, Ba1.5NbTe2O9 and Cd0.5BaNbTe2O9, are given.
X-Ray Powder Diffraction Data for Wolfeite: (Fe0.59Mn0.40Mg0.01)2PO4(OH)
Authors: Antenucci Diano , Fontan Francois , Fransolet Andre-Mathieu
Published: January 2013

Wolfeite (Fe0.59Mn0.40Mg0.01)2PO4(OH) from the Hagendorf-Sud pegmatite, Bavaria, Federal Republic of Germany, yields unit-cell parameters of: a = 12.319(1), b = 13.280(2), c = 9.840(1) Å and β = 108° 24(1). Dmeas. = 3.82(2); Dcalc. = 3.88. An indexed powder diffraction pattern is given.
Powder Diffraction Data for Synthetic Pargasite, Scandian Pargasite and Their Fluorine Analogues: NaCa2Mg4(Al,Sc)Si6Al2O22(OH,F)2
Authors: Raudsepp Mati , Turnock Allan C. , Hawthorne Frank C.
Published: January 2013

Indexed X-ray powder diffraction data and crystal data are reported for: synthetic pargasite (P: NaCa2Mg4AlSi6Al2O22(OH)2), fluor-pargasite (FP: NaCa2Mg4AlSi6Al2O22F2), scandian pargasite (SP: NaCa2Mg4.4Sc0.6Si6Al2O22(OH)2) and scandian fluor-pargasite (SFP: NaCa2Mg4.2Sc0.8Si6Al2O22F2).
Basic Aspects of X-Ray Absorption In Quantitative Diffraction Analysis of Powder Mixtures
Authors: Alexander Leroy , Klug Harold P.
Published: January 2013

The mathematical relationships are developed which are pertinent to the quantitative analysis of powder mixtures for the case of diffraction from the surface of a flat powder specimen. These formulas relate the diffracted intensity to the absorptive properties of the sample. Three important cases are treated: (1) Mixture of n components; absorbing powder of the unknown equal to that of the matrix; concentration proportional to intensity. Direct analysis is permitted. (2) Binary mixture; absorbing powder of the unknown not equal to that of the diluent; concentration not proportional to intensity. Direct analysis is possible by means of calibration curves prepared from synthetic mixtures. (3) Mixture of n components; absorbing power of the unknown not equal to that of the matrix; general case. Analysis is accomplished by the addition of an internal standard. Concentration is proportional to the ratio of the intensity of a selected reflection from the unknown to the intensity of a reflection from the internal standard.
X-Ray Diffraction Profile Analysis of Powdered Samples
Authors: Stanisz G.J. , Holender J.M. , Sołtys J.
Published: January 2013

A quantitative phase analysis often requires advanced numerical studies to determine the appropriate intensity values. In this paper the method of fitting analytical functions to the experimental profile is applied to X-ray powder diffraction patterns obtained with FeK radiation. In the present work, the authors examine some problems connected with numerical studies, especially the function describing the experimental profile. The usefulness of the α2 elimination procedure and the angular dependence FWHM are also examined.
Diffraction Peak Broadening Studies in Al2O3 (Whisker) Composites
Authors: Balasingh C. , Abuhasan Alias , Predecki P. K.
Published: January 2013

Diffraction peak broadening analyses were carried out on diffraction profiles of several reflections from hot-pressed α-Al2O3 containing 29, 18 and 10 volume % β-SiC whiskers. The data were analyzed and compared using four different integral breadth methods for microstrain and crystalline size. All four methods gave comparable results, within an order of magnitude, for the microstrains in each phase: (2-15 × 10−4 for the matrix and (6-19 × 10−4 for the whiskers). Microstrains in both matrix and whiskers decreased with decreasing volume % of whiskers for all four methods. Trends in the crystallite size were less consistent but for the matgrix, an incrfease from ∼665 to 1565Å was found with decreasing whisker content using DeKeijser's method.
XRD Microstructural Characterization of Tetragonal Pure Zirconia Powders Obtained by Controlled Hydrolysis of Zirconium Alkoxides
Authors: Scardi P. , Lutterotti L. , Di Maggio R.
Published: January 2013

A new preparation procedure to obtain tetragonal pure zirconia powders is reported together with a detailed analysis of the profile of X-ray Diffraction (XRD) peaks. The crystallization kinetic up to 800°C is described through r.m.s. microstrain and crystallite size distributions. The results of two methods of profile analysis are compared. After thermal treatments up to 100°C the samples of amorphous gel prepared crystallize in the tetragonal structure. The monoclinic phase occurs only above this temperature. Moreover the tetragonal to monoclinic transformation has a strong effect in changing the shape of the distributions. Studying the crystallite size distributions we can infer a critical size of about 300 Å for the tetragonal crystallites to transform. The shape of the mean crystallite of a fully tetragonal sample is also described.
A Simplified Sample Preparation Method for Multiple Guinier Cameras
Authors: Sperling Z.
Published: January 2013

Described is a method of sample preparation for multiple Guinier Cameras (DeWolff, 1948). This technique practically eliminates cross-contamination of adjacent samples and is easy to employ.

Samples for Guinier cameras are usually applied to a thin adhesive coated foil. For multiple Guinier cameras, however, samples pose some technical problems. Manufacturers usually supply a slotted die for sample preparation. Figure 1 shows schematically such a die for a Seifert/Huber camera. For this type of camera, the manufacturer recommends application of the powdered sample by means of a small brush, or by dusting while the adjacent slots are covered by adhesive tape (Seifert, undated). These methods are simple, but easily result in sample being spilled into an adjacent slot. The following method, though involving more steps, eliminates this problem.
X–Ray Powder Diffraction Data for Synthetic Varieties of Tetrahedrite
Authors: Johnson Neil E.
Published: January 2013

A series of five synthetic tetrahedrite-group minerals has been prepared and examined using powder X-ray diffraction in order to update current powder data and provide a validation test of cell dimension prediction equations. The tetrahedrites (nominally (Cu10X2)Sb4S13 with X = Zn, Cd, Mn, Hg and Fe) have the following properties: zincian tetrahedrite, a = 10.3833 (1) Å, Dx = 4.974 (1) g/cm3, F30 = 264 (0.004, 31), M20 = 279; cadmian tetrahedrite, a = 10.5066 (1) Å, Dx = 5.073 (1) g/cm3, F30 = 208 (0.004, 37), M20 = 249; manganoan tetrahedrite, a = 10.4384 (1) Å, Dx = 4.822 (1) g/cm3, F30 = 274 (0.003, 33), M20 = 302; mercurian tetrahedrite, a = 10.5071 (1) Å, Dx = 5.570 (1) g/cm3, F30 = 150 (0.006, 35), M20 = 156; ferroan tetrahedrite, a = 10.3630 (1) Å, Dx = 5.002 (1) g/cm3, F30 = 253 (0.004, 33), M20 = 281. The experimental unit cell dimensions obtained in this study are in excellent agreement with calculated values produced using regression equations developed previously.
Comparison of Intensities from Fixed and Variable Divergence X-Ray Diffraction Experiments
Authors: Bowden M.E. , Ryan M.J.
Published: January 2013

Diffracted intensities from an X-ray diffractometer operating with fixed or variable divergence slits were compared, following a reported systematic deviation from the theoretical 1/sinθ intensity ratio between these two slit configurations. The theoretical relationship was found to hold over a wide 2θ range provided the anti-scatter slit did not obstruct the beam at higher diffraction angles as the variable slit increased beam divergence. Such obstruction was found to be a possible explanation for the reported deviation.
The Absorption Correction of Debye-Scherrer Diagrams
Authors: Eckerlin Peter
Published: January 2013

An extension of the Nelson-Riley absorption correction of Debye-Scherrer diagrams is given. This enables the calculation of the shifts of the reflection angles if the absorption coefficient is known. Alternatively, these shifts can be found by including the corresponding coefficient in a least-squares lattice constant refinement.
X-Ray Powder Data for Guanidiniuin Hexafluoro-chromate and -ferrate [C(NH2)3]3CrF6 and [C(NH2)3]3FeF6
Authors: Bukovec Natasa , Bukovec Peter
Published: January 2013

The complexes [C(NH2)3]3MF6, M = Cr, Fe have been isolated from aqueous solutions of the corresponding fluorides. The compounds are isostructural and crystallize in the cubic space group with a = 14.0667 (6) Å for M = Cr, a = 14.1246(8) Å for M = Fe and Z = 8. The MF63− anions are arranged as Na+ and Cl− in the NaCl lattice. Guanidinium cations are distributed on 24-fold general position.
Reference Intensity Ratio and Mass Absorption Measurements of Eleven Biotites
Authors: Kath Randy L. , Spilde Michael N. , Davis Briant L. , Smith Deane K.
Published: January 2013

Pure phase reference intensity ratio determinations were completed on eleven biotites ranging in Fe composition from χFe = 0.058 to χFe = 0.695, where χFe = Fe/(Fe + Mg). The crystal chemistry of biotites requires that the intensity of diffraction for the 00l reflections, and thus the corresponding reference intensity ratio, correlate with the Fe, Mg and Al in the octahedral sites. As Fe occupancy increases in the octahedral site, the Lki for the 00l reflections increases as does the value of ∣F∣2 computed using the Takeda and Ross (1975) biotite model. The ∣F∣2 trend closely parallels the experimental regression of Lki = 6.359χFe + 1.513 (R = 0.91). Observed mass absorption measurements completed by X-ray transmission show a similar trend with μo = 69.36χFe + 47.85 (R = 0.97). Calculated values of μ from biotite chemical analyses agree well with the measured values. These relationships may be used to predict the appropriate Lki needed for quantitative analysis of biotite-bearing specimens if the Fe and Mg content of the biotite can be determined.
Crystal Chemistry and Phase Equilibria Studies of the BaO-R2O3-CuO Systems. II: X-Ray Characterization and Standard Patterns of BaR2O4, R = Lanthanides
Authors: Wong-Ng W. , Paretzkin B.
Published: January 2013

The compounds BaR2O4, where R = La, Nd, Sm, Gd, Eu, Dy, Ho and Er have been prepared from a stoichiometric mixture of BaCO3 and lanthanide oxides, and characterized by X-ray powder diffraction. Standard X-ray patterns of these phases were prepared. In general, BaR2O4 crystallizes in the pervoskite-related CaFe2O4 structure which is orthorhombic with a space group Pnam. The cell parameters of these compounds from R = Er to La range from 10.3729(12) to 10.668(2) Å for a, 12.0699(11) to 12.642(2) Å for b, from 3.4356(4) to 3.7037(10) Å for c, and from 450.14(5) Å3 to 499.51 Å3 for V respectively. A monotonic, linear relationship is obtained when V is plotted against the cube of the ionic radius of R. When R = Tm, Lu and Yb, the BaO·R2O3 composition produced the mixture Ba3R4O9 and the unreacted lanthanide oxide. Under the present experimental conditions, the compound BaRO3 was the predominant component when R = Ce, Pr, and Tb.
Powder Diffraction Data of Three 9-Amino-1,2,3,4- Tetrahydroacridine Alzheimer's Disease Therapeutics
Authors: Bandoli G. , Nicolini M. , Ongaro A.
Published: January 2013

Tacrine hydrochloride monohydrate, velnacrine maleate and suronacrine maleate have been investigated by means of X-ray powder diffraction. The unit cell dimensions, determined by single-crystal diffraction data, agree well with those of powder diffraction analysis, which is characterized by good figures of merit for the three drugs. Present work assures that single-crystals are good representatives of the commercial powdered samples, since experimental and simulated (from structure determination) powder patterns are practically identical.
Confirmation of the new technique for measuring the linear thermal expansion of silicon
Authors: Fengchao Liu
Published: January 2013

This paper further confirms that the direct measurement of diffraction angles at different temperatures by using the X-ray diffractometer is better than measurement of the lattice parameters for the rapid and accurate determination of the linear thermal expansion of silicon. High purity silicon has the linear expansion coefficient, α= (2.45±0.05) × 10−6/°C at room temperature. This value does not change for doped P-type and N-type silicon.
X-ray powder diffraction data for beryllonite from Stoneham, Maine, U.S.A.
Authors: Frevel Ludo K. , Crowder Cyrus E.
Published: January 2013

Observed and calculated X-ray powder diffraction data are given for the mineral beryllonite, NaBePO4, from Stoneham, Maine, U.S.A. Diffractometer data taken with CoKα1 radiation and Guinier film data registered with CuKα1 radiation are compared. Two independent procedures were employed to index the patterns.
A new high temperature modification of face-centered cubic Y2O3
Authors: Katagiri S. , Ishizawa N. , Marumo F.
Published: January 2013

A new high temperature form of Y2O3 has been synthesized at 2220 °C by a laser beam heating technique. The new form has a face-centered cubic structure with a = 5.2644(3)Å, Z = 2, Dx = 5.14 g/cm3, and is considered to have a fluorite-type structure containing disordered oxygen vacancies.
X-ray powder diffraction pattern of Mo4.8Si3C0.6
Authors: Garin Jorge L. , Mannheim Rodolfo L.
Published: January 2013

The title compound was synthesized by high temperature reaction of the component elements. This phase, formerly classified in the group of Nowotny phases, crystallizes in the hexagonal system with space group P63/mcm. Crystal data and indexed X-ray powder diffraction data are reported.
The influence of surface roughness on diffracted X-ray intensities in Bragg–Brentano geometry and its effect on the structure determination by means of Rietveld analysis
Authors: Pitschke W. , Hermann H. , Mattern N.
Published: January 2013

Measurements of X-ray diffraction patterns of high-Tcsuperconductor and tungsten–carbide powder samples using a Bragg–Brentano diffractometer showed systematic variations of the intensities for different preparation conditions. For specimens with high surface roughness, an angle-dependent decrease of the intensities is observed which is caused by the microabsorption of the X-rays due to the microstructure of the powder sample. In Rietveld analysis, the thermal parameters are strongly influenced by this effect and may tend to negative values. A realistic description of the surface structure of flat powder samples is proposed. Using an analytical approximation for the microabsorption effect and its dependence on the microstructural parameters the Rietveld refinement yields reasonable values for the thermal parameters.
Crystal data of Nitrofurantoin C8H6N4O5
Authors: Bandoli G. , Ongaro A. , Lotto F. , Rossi M.
Published: January 2013

X-ray powder diffraction of Nitrofurantoin C8H6N4O5 reveals that the compound crystallizes in a monoclinic unit cell with the powder data unit cell parameters of a = 7.852(2), b= 6.497(1), c = 18.927(5) Å, β=93.15(2)°, V=964.1(2) Å3. The unit cell dimensions determined by single crystal agree very well with those of powder diffraction analysis. A comparison with the Powder Diffraction File (PDF) 34-1603 indicates that the present data provide a more precise match to the unit cell, include additional weak reflections, along with the indexing of the powder pattern.
Determination of depth profiles from X-ray diffraction data
Authors: Predecki Paul
Published: January 2013

A direct method is described for determining depth profiles (z-profiles) of diffraction data from experimentally determined τ-profiles, where z is the depth beneath the sample surface and τ is the 1/e penetration depth of the X-ray beam. With certain assumptions, the relation between these two profile functions can be expressed in the form of a Laplace transform. The criteria for fitting experimental τ-data to functions which can be utilized by the method are described. The method was applied to two τ-data sets taken from the literature: (1) of residual strain in an A1 thin film and (2) of residual stress in a surface ground A12O3/5vol% TiC composite. For each data set, it was found that the z-profiles obtained were of two types: oscillatory and nonoscillatory. The nonoscillatory profiles appeared to be qualitatively consistent for a given data set. The oscillatory profiles were considered to be not physically realistic. For the data sets considered, the nonoscillatory z-profiles were found to lie consistently above the corresponding τ-profiles, and to approach the τ-profiles at large z, as expected from the relation between the two.
Full-profile Rietveld quantitative XRD analysis of Portland cement: Standard XRD profiles for the major phase tricalcium silicate (C3S: 3CaO.SiO2)
Authors: Taylor J. C. , Aldridge L. P.
Published: January 2013

The calculated XRD profiles of alite (impure Ca3SiO5, the major phase in Portland cement) derived from seven postulated crystal structures for alite were compared with a measured alite profile, extracted from the XRD pattern of a standard Portland cement. Only two of these profiles were found suitable for multiphase Rietveld phase quantification, namely those given by the monoclinic superlattice and triclinic models. These, however, gave very slow computing times because the large low-symmetry structures generated many X-ray reflections over the pattern. Also tested was an “observed” standard profile for alite, derived from experimental alite profiles, and generated using the (hkl) file feature of the SIROQUANT P.C. quantitative analysis system. This file was based on rhombohedral pseudosymmetry and contained very few (hkl) reflections, compared to the low-symmetry models (64 reflections instead of 951 for the monoclinic and 1691 for the triclinic models, respectively). The latter standard profile gave the best fit to the known phase concentrations and gave computing times which were shorter by factors of 2.5 and 4.9 than those for the monoclinic and triclinic standard profiles, respectively.
Complete sets of factors for absorption correction and air scattering subtraction in X-ray powder diffraction of loosely packed samples
Authors: Ottani Stefano , Riello Pietro , Polizzi Stefano
Published: January 2013

Complete sets of correction factors for absorption and air scattering effects in X-ray powder diffraction are reported. Both symmetrical reflection and transmission techniques are considered and boundary conditions to be tested for any given value of scattering angles are listed. This may prove particularly useful on coding computer programs for correction of raw intensity data files. Effects of interstitial volume on correction for absorption and subtraction of air scattering were investigated. For samples of high interstitial volume, like loosely packed powders or aerogels, the contribution from air trapped inside the specimen is significant and leads to expressions of the air scattering correction factors different from those commonly reported in the literature.
An Excel macro for transforming X-ray powder diffraction data to spreadsheet format
Authors: Chakrabarty Tapan , Webb Dave W. , Longo John M.
Published: January 2013

An Excel command macro has been developed which directly transforms X-ray powder diffraction data to a spreadsheet format. This spreadsheet format offers a number of data reduction and plotting capabilities not available in a diffractometer's software. The conventional approach uses computer programs to transform the data outside a spreadsheet. The development of these programs is not a simple process, and requires the user to be familiar with computer programming and the software of a diffractometer. Furthermore, these programs are diffractometer-specific. A different approach is followed in which an Excel macro transforms the data within a spreadsheet. This macro, with minor modifications, can be applied generally to treat data from any diffractometer. A copy of the macro and an example illustrating its working principle are included.
Identification of two lead perovskites, Pb2ScTaO6 and Pb(Sc0.5Nb0.5)O3, by X-ray powder diffraction patterns
Authors: Caranoni C. , Lampin P. , Boulesteix C.
Published: January 2013

Substituting cations in materials with the formula Pb2B′B″O6 is more or less ordered on the B sites. High-quality single crystals of Pb2ScTaO6 (PST) and Pb(Sc0.5Nb0.5)O3 (PSN) were prepared from two thermal cycles. A stoichiometric mixture of the constituent oxides was prefired at up to 1000 °C, and then crystals were grown from a PbO–B2O3–PbF2 flux mixture, starting at a temperature of 1100 °C for PSN and 1200 °C for PST. At room temperature, X-ray examination showed that PSN had a perovskite structure with a cubic unit-cell and a refined parameter a = 4.080(1 ) Å, space group Pm3m and Z = 1, whereas PST formed a well-ordered superlattice with a = 8.136(1) Å, Z = 4 and space group Fm3m. In each case a fully indexed powder pattern is presented. The degree of order is estimated to be close to 80% for PST and less than 10% for PSN.
Intensity Calibration Curves for Bragg-Brentano X-Ray Diffractometers
Authors: Matulis C.E. , Taylor J.C.
Published: January 2013

An algorithm has been derived, forming the basis of a computer program called BBCCURV, which calculates a Bragg-Brentano X-ray diffractometer intensity correction curve (intensity correction factor Kivs. 2θi) given the diffractometer and sample dimensions, and the effective (not theoretical) linear absorption coefficient of the sample. Use of this calibration curve gives a set of intensity data free from aberrations, which are caused mainly by sample transparency, curvature of the diffraction cones passing through the receiving slit and possible beam overflow past the specimen at low angles.

The algorithm was confirmed with a full-profile Rietveld refinement of Bragg-Brentano X-ray diffraction data from a H+-ZSM5 zeolite sample. On introducing a BBCCURV correction curve, the profile R-factor over the pattern points dropped from 30.8% to 16.5%, a significantly better fit when the data were corrected with a BBCCURV curve.

BBCCURV intensity calibration curves from LiF (μ= 1.5 mm−1) through zeolites, clays, ZnO, rutile, Pb(NO3)2and finally solid metal (μ= 1000 mm−1) (CoKα) indicate upward revision of the measured diffractometer intensities by factors of between 2 and 10 at 2θ= 5° for these sample types, normalised to a correction factor of 1.0 at 2θ= 44°. Corrections of this magnitude to Bragg-Brentano data are thus significant in full-profile structure refinement and quantitative analysis with Bragg-Brentano data. Use of a variable divergence slit (VDS) is not appropriate in full-profile refinements as the intensity aberrations are magnified, and conversion from VDS data to aberration-free data is sample- and transparency-dependent, and not the simple area (sinθ)−1function generally assumed. Use of a fixed divergence slit with a BBCCURV-type calibration is recommended.