bluuebunny/crossref_metadata_2025_split huggingface dataset:
The POWDER SUITE: Computer Programs for Searching and Accessing the JCPDS-ICDD Powder Diffraction Database
Authors: Toby B.H. , Harlow R. L. , Holomany M. A. 
Published: January 2013

AbstractTwo new VAX/VMS computer programs are presented for accessing and searching the Powder Diffraction File (PDF) (1989) of the JCPDS-International Centre for Diffraction Data (ICDD). The programs use binary mapped index files which affords rapid searches of the database. Program LOGIC permits entries in the database to be selected by chemistry, peak position or name constraints. The selected entries may be displayed, printed or graphed. The program can display or print entries from the full PDF-2 (1989) database, if on-line. Program SEARCH searches for patterns in the database which match an unknown set of peaks; the program may be optimized for a wide variety of applications including identification of component phases in mixtures. Commands may be entered to the programs in two modes. In the “novice-friendly” mode, users must answer questions to select options. However, experienced users may opt to use a concise one-line command syntax. The modes may be mixed.
Identification and Quantification of Unknown Component Phases in Powder Samples by X-Ray Diffractometry
Authors: Kato Masanao , Fujii Sinzo , Ui Takuji , Asada Eiichi 
Published: January 2013

AbstractA method of analysis for X-ray diffractometry is proposed for determining the number and the concentrations of phases in a series of samples of the same multiphase system. This method can be used when n samples containing N phases, where N<n, with different concentrations are given or prepared from a given sample.The method of principal component analysis was applied to the determination of the number of individual phases in multiphase mixtures. A quantification method using the intensity ratio to an arbitrary chosen standard mixture, which is also one of the mixtures to be analyzed, is proposed.In this study, we examined the validity of this method for X-ray diffractograms of two and three component systems. It is shown that the values determined by the present method are in good agreement with the prepared concentrations of the samples.
Mass Absorption Corrected X-Ray Powder Diffractograms. Part 1: Measuring Pyrite in Powdered Coals
Authors: Wertz David L. 
Published: January 2013

AbstractAn X-ray analysis method has been developed for the quantitative analysis of pyrite (FeS2) in coals and lignites. Requiring neither the use of external or internal references, the method linearly relates diffraction peak area in the absorption corrected X-ray diffractogram obtained from the finely powdered coal to the pyrite abundance. The [311] diffraction peak of pyrite (FeS2) has been used to develop the analysis protocol. The Argonne premium coals have been used as the experimental subjects. The abundance of pyrite in each coal has been measured from the absorption corrected diffractograms, which has been constructed from the experimentally measured diffraction intensities and the mass absorption coefficient of each coal sample. The accuracy (accessed from the figure-of-merit and the net count uncertainty associated with the 1.63 Å pyrite peak) as well as the lower limit of detection for pyrite in these coals is presented. The role of the mass absorption coefficient in the conversion of the measured intensity to the absorption corrected intensity is discussed.
Indexing of the Powder Diffraction Pattern of Yttrium Oxalate Dihydrate
Authors: Louër D. , Deneuve F. , Ecochard F. 
Published: January 2013

AbstractYttrium oxalate dihydrate, Y2(C2O4)3.2H2O, has been investigated by means of X-ray powder diffraction. Unit cell dimensions were determined by an indexing program based on the variation of parameters by successive dichotomies. The diffractometer data were collected with strictly monochromatic radiation. A monoclinic cell was found: a=9.3811(8)Å, b=11.6385(15)Å, c=5.9726(7)Å, β=96.079(8)°, which is characterized by the figures of merit M20=87 and F30=112 (0.0065,41). A preliminary analysis of the anisotropic line broadening has revealed some microstructural properties. It is shown that line broadening is mainly due to a micro-strain effect.
Determination of the Relative Amounts of α-carbamazepine and β-carbamazepine in a Mixture by Powder X-Ray Diffractometry
Authors: Suryanarayanan Raj 
Published: January 2013

AbstractA powder X-ray diffraction technique has been developed to quantify the relative amounts of α-carbamazepine (A) and β-carbamazepine (B) when they occur as a mixture. The theoretical basis of this technique was developed in 1948 by Alexander and Klug (Anal. Chem., 20:886-889). The powder X-ray diffraction patterns of A and B revealed that the line with d-spacing of 10.1 Å was unique to A. The ratio of the integrated intensity of the 10.1 Å line in a mixture of A and B, to the intensity of the 10.1 Å line in a sample consisting of only A, was calculated as a function of weight fraction of A in the mixture. These ratios were also experimentally determined, and there was a good agreement between the theoretical and experimental intensity ratios. The particle size of the samples, the sample preparation technique and the experimental conditions were controlled so as to eliminate the major sources of error in powder X-ray diffractometry. In order to minimize preferred orientation of the particles, a sample holder was specially fabricated.
On The Harris Texture Index
Authors: Valvoda V. , Järvinen M. 
Published: January 2013

AbstractThe texture index introduced by Harris (1952) is reconsidered from the point of view of the orientation distribution of crystallites in a flat powder specimen. It is shown that the texture index can be used as an approximate measure of texture degree or as a texture correction factor in cases of a weak texture. Its failure in both these aspects for the strong textures is caused by an incorrect averaging of pole densities contained in the original definition of this quantity.
X-Ray Powder Structural Analysis of the Spinel Polymorph of Fe2SiO4
Authors: Ding Jianping , Li De-yu , Fu Ping-qiu 
Published: January 2013

AbstractThe crystal structure of the spinel polymorph of Fe2SiO4, synthesized at high temperature (900°C) and high pressure (70 kbar), was studied by the Rietveld analysis of X-ray powder diffraction data collected with a Guinier-Hägg camera. The compound is cubic, space group , with cell dimension: a= 8.2413(6) Å, V= 559.8(1) Å3, Z= 8, Cell Wt. = 1630.2, Dx= 4.835 g·cm−3, Do= 4.75 g·cm−3. The figure of merit is F10= 92(0.011, 10). The final R value is RF= 0.058. The crystal has a mixed normal-inverse spinel structure. The site occupancy refinement showed that 37.9% of the silicon was found in the octahedral site (M site), while 18.9% of the iron occupied the tetrahedral site (T site). Due to the larger displacement of Si4+ion by Fe2+ion, the positional parameter of oxygen atom (0.3689) is smaller than that of X-ray single crystal structure (0.3658), and the average Si-O bond (1.697(1)Å) is longer and Fe-O bond (2.112(1)Å) is shorter than those of X-ray single crystal structure.
Powder Diffraction Data for Synthetic Potassium-Richterite, Nickel-Potassium-Richterite and Cobalt-Potassium-Richterite
Authors: Raudsepp Mati , Ventura Giancarlo Della , Hawthorne Frank C. , Robert Jean-Louis 
Published: January 2013

AbstractIndexed X-ray powder diffraction data derived from Rietveld crystal structure refinements are reported for synthetic potassium-richterite (KRC: K[CaNa]Mg5Si8O22(OH)2), nickel-potassium-richterite (NIKRC:K[CaNa] Ni5Si8O22(OH2) and cobalt-potassium-richterite (COKRC:K[CaNa]Co5Si8O22 (OH2). The following dimensions were obtained: KRC: a = 10.0547(8), b = 17.997(1), c = 5.2746(4)Å, β = 104.832(5)°; NIKRC: a = 10.0297(7), b = 17.942(1), c = 5.2576(4)Å, β = 104.982(5)°; COKRC: a = 10.1166(9), b = 18.066(1), c = 5.2752 (4)Å, β= 104.846(6)°.
Determination of Amorphous Phase in Quartz Powder by X-Ray Powder Diffractometry
Authors: Nakamura Toshihiro , Sameshima Katsumi , Okunaga Kiyoyuki , Sugiura Yoshitaka , Sato Jun 
Published: January 2013

AbstractA powder diffraction method was applied to the quantitative analysis of amorphous silica in several quartz powders. Two calibration methods, i.e., direct analysis and the standard addition method were examined. Calibration mixtures were made by mixing a standard silica gel powder ground to under 5 μm particle size with a matrix quartz powder which was ground to 10 to 40 μm particle size and treated with NaOH solution to remove the amorphous phase caused by grinding. Intensity of the amorphous halo was measured at 23.0° 2θ, and the background intensity at 53.0° 2θ was subtracted. Linear calibration curves were obtained over the ranges of 0 to 50 wt% by direct analysis and 0 to 20 wt% by standard addition methods, respectively. The analytical results obtained by the two calibration methods were in good agreement with each other. The relative standard deviations for 4.3 wt% of amorphous silica were 4.6% by the direct analysis and 5.4% by the standard addition method. These methods were successfully applied to a correction of reference intensity ratios (RIR) for several quartz powders containing amorphous silica. After the correction for amorphous content, the relative standard deviations of the RIR values for quartz powders became smaller.
X-Ray Diffraction Data for SnO2. An Illustration of the New Powder Data Evaluation Methods
Authors: McCarthy Gregory J. , Welton Jean M. 
Published: January 2013

AbstractThe Powder Diffraction File (PDF) X-ray diffraction pattern for SnO2 (cassiterite, syn), determined in the early 1950's at the National Bureau of Standards, was evaluated using the NBS*AIDS83 editorial review program and a calculated powder pattern. Systematic errors in d-spacings and relative intensities were attributed to the lack of an iterative least-squares refinement of unit cell parameters, to inadequate precision in reporting d-spacings, to poor sensitivity to high angle reflections, and to detector dead time. A new SnO2 pattern was prepared and used to illustrate criteria for evaluation of powder patterns. An R-Factor for quantifying agreement between observed and calculated relative intensities was utilized. The systematic errors in the earlier pattern occurred at higher angles and did not hinder its usefulness for identification purposes.
Crystal Data for [Cu(C15H11N3)X2]·nH2O [X−=NCO (n=1); NCSe and N3(n=ø)] Compounds
Authors: Vía J. , García A. , Mesa J. L. , Arriortua M. I. , Rojo T. 
Published: January 2013

AbstractThree members of the family [CuC15H11N3)X2]·nH2O [X−=NCO (n=1), NCSe and N3 (n=ø)], C15H11N3=2,2′:6′,2″ – terpyridine (terpy), have been prepared by reaction in solution. Crystal data determined widi the aid of single crystal methods, powder diffraction data, and densities determined by flotation methods are presented.
Computer Programs for Standardless Quantitative Analysis of Minerals Using the Full Powder Diffraction Profile
Authors: Taylor J. C. 
Published: January 2013

AbstractA Fortran 77 computer program has been developed for the quantitative analysis of minerals by multiphase profile analysis of the complete powder diffraction pattern. Featured are full-matrix least-squares refinement of 14 Rietveld “instrumental parameters” (phase scales, asymmetry, preferred orientations (March model), linewidths, instrument zero, lineshapes and unit cell dimensions), Brindley particle absorption contrast factors and amorphicity corrections. The program uses a crystal structure Databank, which contains information on absorption coefficients, unit cell data and crystal structures for some 90 common minerals. New minerals can be easily added. Structure parameters are also refinable by a profile decomposition method using a program called STRUCT. The sum of the calculated patterns, derived from the crystal structure data, is fitted to the observed pattern by a program called TRACSCAL which runs in singlepass multiphase mode and, after the above corrections have been applied, the weight percentages of the component phases are calculated from the Rietveld scaling factors.The program runs on an IBM-compatible AT computer with 640K of RAM, on an extended memory AT, or a mainframe system. Examples of its use are given with standard mixtures and naturally occurring specimens. On an AT computer with 20MHz clock speed a scaling run, including data input, reading of the pattern, processing of (hkl) files, calculation of the profile and one cycle of least squares fitting takes about 30 seconds for binary standard mixtures and about 2.5 minutes for a 7-phase natural bauxite pattern containing 320 independent (hkl) reflections.
Determination of Crystal Structure of Cd3(BO3)2 by Powder X-Ray Diffraction
Authors: Laureiro Y. , Veiga M.L. , López M.L. , García-Martín S. , Jerez A. , Pico C. 
Published: January 2013

AbstractCd3(BO3)2 was prepared by a solid state reaction between B(OH)3 and Cd(OH)2 at low temperatures ranging between 523° and 623° and at a pressure of 10−4 – 10−5 Hg mm. The crystal structure has been refined by Rietveld analysis of X-ray powder diffraction data. The compound crystallizes in the orthorhombic system, space group Pnnm, Z = 2, with cell parameters of a = 5.967(5) Å, b = 4.78 (0) Å and c = 9.009(5) Å.
X-Ray Powder Diffraction Data for BaCu(C2O4)2·6H2O
Authors: Wong-Ng Winnie , Rhine Wendell E. , Hallock Robert B. 
Published: January 2013

AbstractAn indexed powder diffraction pattern and related crystallographic data are reported for a new phase, BaCu(C2O4)2·6H2O, which was a major product in the coprecipitation of barium and copper oxalates.
Expanded Use of the Rietveld Method in Studies of Phase Abundance in Multiphase Mixtures
Authors: Hill R.J. 
Published: January 2013

AbstractSimple relationships exist between the individual phase scale factors derived from Rietveld analysis of multiphase mixtures and (i) the ‘reference intensity ratio’ used in traditional methods of discrete-peak phase analysis, (ii) the phase abundance itself and (iii) the relative pattern intensities in simulated powder patterns. These relationships are shown to follow naturally from the fundamental integrated-intensity phase-analysis equations provided in standard texts. In the event that preferred orientation, crystallinity, extinction and/or microabsorption cannot be adequately incorporated into the Rietveld models for individual phases, it is demonstrated that the Rietveldab initio‘pattern intensity constants’ can be scaled/calibrated experimentally, as in other whole-pattern methods of analysis, while retaining all the advantages of the Rietveld method.
Powder Diffraction Data of Four Complex Cesium Thiocyanates: Cs3A[B2(SCN)7], with A = Sr, Ba and B = Ag, Cu
Authors: Garsche Markus , Tillmanns Ekkehart , Bauer Thomas , Fischer Reinhard X. , Bohaty Ladislav 
Published: January 2013

AbstractSingle crystals of Cs3A[B2(SCN)7] with A = Sr, Ba and B = Ag, Cu have been synthesized from aqueous solutions by the evaporation method. The complex thiocyanates are isostructural and crystallize in the tetragonal system with space group.Complete crystal data and optical data for the four compounds are reported. An X-ray powder diffraction pattern for Cs3Sr[Cu2(SCN)7] is given.
Geiger Counter Spectrometer for Industrial Research
Authors: Friedman H. 
Published: January 2013

X-ray diffraction has many applications in the chemical and metallurgical industries, but its techniques have been confined until recently to the laboratory and to highly trained personnel. Conventional procedure entails photographic exposure, processing, and density comparisons of the finished film strips.The Geiger counter spectrometer described below measures x-ray intensities and diffraction angles directly, without intermediate photographic steps. It is simple enough for unskilled operators performing routine industrial processes yet also meets the precise requirements of laboratory research. The instrument was developed at the Naval Research Laboratory, where it has been in regular use for the past two years.
The Linear Coefficient of Thermal Expansion of Silicon at Room Temperature
Authors: Fengchao Liu , Bin Zheng 
Published: January 2013

AbstractThe linear coefficient of thermal expansion for three silicon single-crystal samples, taken from the head, middle, and tail of the same boule, and their powder samples have been measured at room temperature by using an X-ray powder diffractometer. All samples yield the same expansion valueα=2.45 (± 0.04) × 10−6°C at 25 °C. The results of this experiment show that the linear coefficient of thermal expansion of silicon at room temperature is not dependent on its single-crystal state or its powder state.
Powder Diffraction – A Journal Citation Study
Authors: Fiala Jaroslav , Bodák Vlastimil , Dubovinský Miroslav 
Published: January 2013

AbstractCitation analysis of the articles that appeared in the first five volumes of the journal Powder Diffraction showed that it is clearly a journal of crystallography with strong ties to materials science, mineralogy and analytical chemistry. This specific orientation makes Powder Diffraction invaluable in the existing network of scientific journals.
X-Ray Powder Diffraction Study of 2,2′,2″ triamino-triethylamine-Ni(II)-di-thiocyanate by Transmission PSD Diffractometer and Rietveld Techniques
Authors: Lundtoft Britta , Rasmussen Svend Erik 
Published: January 2013

AbstractX-Ray powder diffraction data for the compound 2,2′,2″-triamino-triethylamine-Ni(II)-di-thiocyanate were obtained by transmission diffractometric methods at 20°C - 22°C. Two data sets were collected with CuKα1 radiation (λ = 1.54056 Å) one with Si as an internal standard (a = 5.430825 Å) and one without.The deep blue crystals are orthorhombic of space group P212121. Peak positions were corrected by aid of the Si peaks in the first data set. Refinements of lattice constants from indexed reflections yielded the following values: a = 10.8524(18) Å; b = 14.7249(16) Å; c = 8.6511(11) Å; Dx = 1.542 Mg/m3. The second data set was used for a Rietveld refinement. The lattice constants obtained by this method are: a = 10.8451(5) Å; b = 14.7148 Å; c = 8.6447(4) Å.
The Crystal Structures and Powder Diffraction Patterns of the Uranium Tellurides: A Critical Review
Authors: Snyder Robert L. , Nichols Monte C. , Boehme Dale R. 
Published: January 2013

AbstractA critical review of all the reported structures and powder diffraction patterns in the uranium telluride system has been undertaken. Our recommendations are:1. Structures that are correct:• Cubic – UTe: no experimental pattern exists. Retain calculated 15–865.• Cubic – U3Te4: retain poor quality 12-610 but adopt the pattern calculated here.• Cubic U2Te3: no experimental pattern exists. Adopt pattern calculated here.• Orthorhombic UTe2: Adopt the new pattern of Boehme et al.• Monoclinic αUTe3: Adopt the new pattern of Boehme et al.• Orthorhombic βUTe3: Adopt the pattern calculated here.• Orthorhombic UTe5: Adopt the new pattern of Boeheme et al.2. Structures in need of refinement:• Orthorhombic U2Te3: Adopt pattern calculated here over 34-807.• Hexagonal U7Te12: Adopt pattern calculated here but retain 24-1368.• Orthorhombic UTe1.78: Adopt pattern calculated here and retain our modified 21-1404 reported for U4Te7.• Orthorhombic UTe2.5: Adopt pattern calculated here.• Orthorhombic UTe3.4: Accept recent pattern of Boehme et al.3. Phases for which no structures or reliable patterns exist:• Orthorhombic U3Te4: no published pattern.• Tetragonal U3Te5: three patterns 21-1407, 34-766 and 34-896 exist but all are of very poor quality.4. Phases which probably do not exist:• Tetragonal UTe1.77• Tetragonal UTe2• Cubic UTe2• U3Te7 (21-1402)• U3Te8 (21-1406)
The Background in X-Ray Powder Diffractograms: A Case Study of Rietveld Analysis of Minor Phases Using Ni-Filtered and Graphite-Monochromated Radiation
Authors: Hill R.J. 
Published: January 2013

AbstractHigh resolution X-ray powder diffraction data have been collected with Bragg-Brentano geometry on samples of MgO using Ni-filtered and graphite-monochromated CuKαradiation. Selection of the characteristic radiation by Ni-filtering produces severe peak asymmetry, truncates the low-angle foot of the peak, lowers the general level of background on the low angle side, and leaves a remnant Kβpeak for all foils of reasonable thickness. When step-scan data produced by this method are used for Rietveld analysis, all of these features cause difficulties in fitting a smooth function to the background and in successfully modelling the detailed profiles of the peaks. On the other hand, Kαradiation from a diffracted-beam monochromator provides inherently more symmetric peaks and a smoothly varying background on both sides of the peak centre, both of which effects can be adequately modelled during Rietveld analysis. The primary disadvantage with monochromation is that, even with very careful setting of the pulse height discrimination, the monochromator may pass a small proportion of theλ/2 component of the incident radiation. In samples containing small quantities (i.e., 2 wt%, or less) of impurity phases, the undesirable features of the diffractometer profile (i.e., asymmetric and truncated background, and Kβandλ/2 peaks) can be of similar intensity to the main peaks arising from the impurities (as well as substructure peaks from the primary phases), thereby leading to difficulties in their identification and quantification. Nevertheless, with due care and long data collection times, the abundances of minor phases can be measured with Rietveld analysis down to levels of the order of 0.1 wt%.
A Simplified Correction for Surface Roughness Effects in X-Ray Diffractometric Investigations
Authors: Vasudevan R. , Ramesh R. , Pathiraj B. , Kolster B.H. 
Published: January 2013

AbstractThe importance of surface roughness to the measurement of integrated intensity in X-ray powder diffraction is discussed following studies conducted with materials in both powder and bulk (rolled sheet/billet) forms possessing different absorption characteristics. A simple procedure is described which allows for surface roughness effect.
A Review of the XRD Data of the Phases Present in the CaO-SrO-PbO System
Authors: Reardon Brian J. , Hubbard Camden R. 
Published: January 2013

AbstractX-ray powder patterns for the phases in the CaO-SrO-PbO ternary system, along with the corresponding crystal structures, were obtained from the literature and from the Powder Diffraction File. Available XRD patterns were compared with each other and with a simulated pattern for each phase, yielding a recommended reference pattern. The simulated powder patterns presented here deal with the phases found within the (Ca,Sr)2PbO4solid solution series and are recommended for the Powder Diffraction File (PDF).
The Crystal Structure of Pressure-Induced Phases of In2Te3and Ga2Te3
Authors: Serebryanaya N.R. 
Published: January 2013

AbstractPhase transitions were found with use of an in situX-ray anvil-type of apparatus with a boron annulus at pressures up to 12 GPa. The disordering of vacancies in the In sub-structure, or α→βtransition, was found in In2Te3at p > 1.9 GPa. The next transformation from the β-form into the Bi2Te3type of structure was observed in both sesquitellurides at 2.0 GPa and 5.0 GPa for In2TGe3and Ga2Te3respectively. The In2Te3metastable phase of the Bi2Te3resulted from heating up to 200° C at p > 4.0 GPa, and it remained in a normal condition on release of the pressure. The X-ray powder diffraction data of pressure-induced phases, volume changes and bulk modulus of both sesquitellurides are given. The compressibility anisotropy of the layer pressure-induced phase was observed. The mechanism of the crystal structure transformation from the face-centered cubic structure into the Bi2Te3type is proposed to be due to the displacement of atoms from the space diagonal of the cube [111] into [112]-cubic direction and the rhombohedral distortion of the angle between these directions.