bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

AbstractX-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

AbstractA 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

AbstractThe 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

AbstractObserved 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

AbstractSince 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

AbstractThirteen 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

AbstractWolfeite (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

AbstractIndexed 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

AbstractThe 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

AbstractA 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

AbstractDiffraction 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

AbstractA 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

AbstractA 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

AbstractDiffracted 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

AbstractAn 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

AbstractThe 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

AbstractPure 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

AbstractThe 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

AbstractTacrine 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.
Intensity Calibration Curves for Bragg-Brentano X-Ray Diffractometers
Authors: Matulis C.E. , Taylor J.C. 
Published: January 2013

AbstractAn 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.
Powder X-Ray Diffraction Data for the Superconducting Phase TlCaBa2Cu2O7−δ
Authors: Aselage Terry L. , Eatough Michael O. 
Published: January 2013

High temperature superconducting phases in the Tl-Ca-Ba-Cu-O system are ideally represented by the formula TlmCan−1Ba2CunO2(n+1)+m, with m either 1 or 2 and n = 1 to at least 3 (Parkin et at., 1988). Each of these phases contains one or more of the nearly planar CuO2sheets common to the cuprate superconductors. A single Ca atom separates adjacent CuO2sheets (n > 1). Single or double rock salt-like Tl-O layers are separated from the Can−1CunO2nregions by single Ba-O layers. Each of the Ca-containing members of this family crystallizes in a tetgragonal unit cell, with space group 14/mmm for the m = 2 series and P4/mmm for the m = 1 series.Despite the general interest in this family of superconductors, little has been reported about the m = 1, n = 2 member, TlCaBa2Cu2O7−δ, hereafter called 1122. This lack of work is due at least in part to the difficulty in synthesizing the pure compound (Michel et at., 1991). Additionally, technological interest has focused on members of the family with higher superconducting transition temperatures, particularly Tl2Ca2Ba2Cu3Oywith Tcup to 125 K. The critical temperature of 1122 has been reported from as low as 50 K (Hervieu et al., 1988) to as high as 103 K (Morosin et al., 1988), and at several values in between (Ganguli et al., 1988; Liang et al., 1988). Most of the samples had other superconducting phases in addition to 1122. Because of the nearly identical a axis lengths of the unit cells of the Tl-family of superconductors, syntactic intergrowths may be present in such multiphase samples.
A Crystallographic Re-Examination of the (Fe,W)6C Phase Field in the Fe-W-C System
Authors: Azubike D.C. , Chrysanthou A. , Igiehon U.O. 
Published: January 2013

AbstractA more accurate X-ray diffraction pattern for the high speed steel carbide Fe3W3C is presented. This pattern includes the low angle reflections omitted from previous studies. A wider homogeneity range for the M6C carbide phase at 1200° C is suggested.
X-Ray Powder Diffraction Data for Tetragonal Zirconia Solid Solutions in System ZrO2-YTaO4
Authors: Kim Dae-Joon , Hubbard Camden R. 
Published: January 2013

AbstractTetragonal zirconia (t- ZrCO2) can be stabilized with 15 to 22 mol% YTaO4. X-ray powder diffraction data for the end members of the solid solution series Zr0.76Y0.12Ta0.12O2 and Zr0.66Y0.17Ta0.17O2 are reported along with lattice parameters across the single phase region. These tetragonal zirconias are characterized by large tetragonalities (c/ √ 2a > 1.0203) and nontransformability to the monoclinic structure.
Barium Rare Earth Titanates: X-Ray Characterization of BaR2Ti3O10 and BaR2Ti4O12: R = Lanthanide
Authors: Jing X. , Zheng C. , West A.R. 
Published: January 2013

AbstractThe compounds, BaR2Ti3O10: R = La, Pr, Nd and Sm; BaR2Ti4O12: R = La, Pr, Sm, Gd, Eu have been prepared by solid state reaction and characterized by X-ray powder diffraction. Unit cell data are summarised; lattice parameters and unit cell volumes increase approximately linearly with lanthanide ion size.
A Suggestion on the Standard X-Ray Powder Diffraction Pattern of Barium Ferrite
Authors: Shin H.S. , Kwon S.-J. 
Published: January 2013

AbstractWe have examined the barium ferrite powder X-ray diffraction patterns in the PDF using experimental and calculated diffractograms. An improved calculated diffractogram is proposed. The result indicates that the primary peak of barium ferrite is not (107) but is (114).
An Application of Calculated X-Ray Diffraction Patterns in the Analysis of Reference Powder Data: Trivalent Metal Sulfates
Authors: Pollack Sidney S. , McCarthy Gregory J. , Holzer Jean M. 
Published: January 2013

AbstractPowder diffraction patterns have been calculated for nine isostructural rhombohedral M2(SO4)3 (M = Sc, Ti, V, Cr, Fe, Ga, Y, Rh, In) phases, and for four isostructural monoclinic M2(SO4)3 (M = V, Fe, In, Tl) phases. The pattern for monoclinic Fe2(SO4)3 is the first reported for this phase. Because structure data are available only for the two Fe2(SO4)3 polymorphs, the powder patterns of the other trivalent metal sulfates were approximated using the structure data of the isostructural Fe phases with the scattering factors and previously determined cell parameters of the various metal sulfates. These calculated patterns are termed an approximation by isostruduralism.The calculated patterns were used to evaluate reference powder data for these phases in the Powder Diffraction File (PDF). All but two of the PDF patterns were found to differ substantially from the calculated patterns in the stronger peaks used for identification, and to be missing weak peaks that may be confused for impurities during phase identification.