X-Ray Powder Diffraction Study of the Tungsten Bronze Type Barium Sodium Niobates

1990 ◽  
Vol 5 (3) ◽  
pp. 125-130 ◽  
Author(s):  
M. Shimazu ◽  
Y. Kubota ◽  
T. Wada ◽  
S. Tsutsumi
Keyword(s):  
Solid Solution ◽  
Diffraction Study ◽  
Powder Diffraction ◽  
Tungsten Bronze ◽  
Higher Order ◽  
Repeated Measurements ◽  
Unit Cell ◽  
Powder Diffraction File ◽  
X Ray ◽  
Solid Solution Range

AbstractBa2NaNb5,O15 and eighteen additional compositions in the NaNbO3-BaNb2O6 system from 60 to 85 mole % BaNb2O6 have been prepared and studied by X-ray powder diffraction. A calculated pattern has been used to aid in indexing the powder pattern of stoichiometric Ba2NaNb5O15(BNN-S). The lattice parameters of BNN-S have been determined from repeated measurements of 2 higher order reflections and are a=b=17.5994(8)Å and c=7.9771(9)Å. A comparison with the Powder Diffraction File (PDF) 34-210 indicates that the present data provide a more precise match to the unit cell, include additional weak reflections and cover a greater 2θ range. There is a tungsten bronzetype solid solution range from 60 to 75 mole % BaNb2O6.

X-ray powder diffraction characterization of Bi14(Sr,Ca)12O33 solid solutions

1996 ◽  
Vol 11 (4) ◽  
pp. 268-275 ◽  
Author(s):  
Winnie Wong-Ng ◽  
F. Jiang ◽  
Bryan R. Jarabek ◽  
Gregory J. McCarthy
Keyword(s):  
Solid Solution ◽  
Powder Diffraction ◽  
Solid Solutions ◽  
Cell Parameter ◽  
X Ray Diffraction ◽  
Powder Diffraction File ◽  
X Ray ◽  
Solid Solution Range

Powder X-ray diffraction was used to investigate the solid solution range of the Bi14SrxCa12−xO33 series in the Bi–Sr–Ca–O system. Solid solution forms over the range 1≤x≤7 in Bi14SrxCa12−xO33. Experimental X-ray reference patterns of selected members with x=1, 3, 5, and 7 have been prepared for the powder diffraction file (PDF). These phases are monoclinic, C2/m, with cell parameter a ranging from 21.473(4) to 21.868(4) Å, b from 4.3564(9) to 4.3898(9) Å, c from 12.753(2) to 12.962(2) Å, β from 102.91(2)° to 102.79(1)°, and V from 1162.9(3) to 1213.5(3) Å3, respectively. These parameters increase monotonically as Ca is continuously replaced by the larger Sr.

X-ray powder diffraction study of ZnGa2Te4

2002 ◽  
Vol 17 (1) ◽  
pp. 41-43 ◽  
Author(s):  
Rashmi ◽  
U. Dhawan
Keyword(s):  
Diffraction Study ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Unit Cell ◽  
Powder Diffraction Data ◽  
Unit Cell Parameters ◽  
Tetrahedral Structure ◽  
X Ray ◽  
Cell Parameters ◽  
Ray Density

ZnGa2Te4 was found to crystallize in a defect tetrahedral structure with possible space group I4(82) with Z=2. Complete X-ray powder diffraction data were obtained and the unit cell parameters a and c and X-ray density were calculated. These were a=0.5930(1) nm, c=1.1859(3) nm, and Dx=5.7×103 kg/m3.

X-ray powder diffraction reference patterns for Bi1−xPbxOCuSe

2016 ◽  
Vol 31 (3) ◽  
pp. 223-228 ◽  
Author(s):  
W. Wong-Ng ◽  
Y. Yan ◽  
J.A. Kaduk ◽  
X.F. Tang
Keyword(s):  
Cell Volume ◽  
Powder Diffraction ◽  
Ionic Radius ◽  
Unit Cell Volume ◽  
Unit Cell ◽  
Powder Diffraction File ◽  
X Ray ◽  
Natural Superlattice ◽  
Diffraction Patterns ◽  
Pb Substitution

The structures and powder X-ray reference diffraction patterns of the “natural superlattice” series Bi1−xPbxOCuSe (x = 0, 0.02, 0.04, 0.06, 0.08, and 0.10) have been investigated. As the ionic radius of Pb2+ is greater than that of Bi3+, the unit-cell volume of Bi1−xPbxOCuSe increases progressively from x = 0 to 0.1, namely, from 137.868(5) to 139.172(11) Å3, as expected. The structure of Bi1−xPbxOCuSe is built from [Bi2(1−x)Pb2xO2]2(1−x)+ layers normal to the c-axis alternating with [Cu2Se2]2(1−x)− fluorite-like layers. Pb substitution in the Bi site of Bi1−xPbxOCuSe leads to the weakening of the “bonding” between the [Bi2(1−x)Pb2xO2]2(1−x)+ and the [Cu2Se2]2(1−x)− layers. Powder patterns of Bi1−xPbxOCuSe were submitted to be included in the Powder Diffraction File.

An Approach to the Solid Solution Problem Using a Computerized Identification Technique

1969 ◽  
Vol 13 ◽  
pp. 539-549
Author(s):  
Gerald G. Johnson ◽  
Frank L. Chan
Keyword(s):  
Solid Solution ◽  
Powder Diffraction ◽  
Lattice Parameter ◽  
Powder Diffraction File ◽  
X Ray ◽  
Complete Solid Solution ◽  
Vegard’S Law ◽  
Identification Technique ◽  
Approximate Composition ◽  
End Members

Since for most real systems, solid solution effects influence the position and intensity of the x-ray powder diffraction pattern, it is desirable and necessary to have an automatic system which will identify standard reference phases regardless of the amount of solid solution. Using the system CdS-ZnS, where the lattice parameter a0 changes from 4.136 to 3.820Å, with complete solid solution over the entire range of composition, an illustrative study was made. This work presents the results obtained from a computer analysis of the powder pattern obtained. It has been found that if the starting chemistry is known and the end members of the series are in the ASTM Powder Diffraction File, that the solid solution can be identified. Once the phases present are identified, a plot following Vegard's law yields the approximate composition of the sample under consideration. These two methods of compositional determination agree quite well. Examples of the computer system and description of the program input and output with interpretation of the results will be discussed.

Standard Data for the Identification of Phases By X-Ray Diffraction

1973 ◽  
Vol 17 ◽  
pp. 20-31
Author(s):  
Howard F. McMurdie
Keyword(s):  
Computer Program ◽  
Single Crystal ◽  
Powder Diffraction ◽  
Unit Cell ◽  
National Bureau ◽  
Crystal Data ◽  
X Ray Diffraction ◽  
Powder Diffraction File ◽  
X Ray ◽  
Standard Data

AbstractThe identification of crystalline phases by x-ray diffraction, either by powder or single crystal techniques requires a dependable body of reference data. It is not only necessary to have data on each phase which are accurate and complete, it also is desirable to have data on as wide a range of compounds as possible, and to have the data organized in such a manner as to be readily usable. The outstanding compilations which approach these goals are the Powder Diffraction File and Crystal Data.The Powder Diffraction File, published by the Joint Committee on Powder Diffraction Standards has data covering about 22,500 phases, both organic and inorganic. These data are of various degrees of accuracy as is indicated by symbols. The File is continuously being improved by the addition of evaluated data from the general literature and by data produced by supporting projects, the principal one being the Joint Committee Associateship at the National Bureau of Standards.To be noted in the File with a star, and to be truly considered standard data a powder pattern must be complete in the sense of including all reflections above the minimum “d” spacing covered, both weak lines and those with large “d” spacings. Since the best test of a pattern is its own internal consistency, the reflections must all have hkl's assigned and must show a good agreement between the spacings observed and those calculated from a refined cell, and they must be consistent with the known space group. This agreement can be best obtained by the use of an internal standard and a computer program. The intensities should be measured by a method which minimizes the effect of crystal orientation.The PDF is provided with search procedure manuals arranged on a scheme of the strongest lines to help in locating data matching that from an unknovm. A computer program for rapid searching is available. A recent development is the inclusion of a “reference intensity” to aid in estimating the quantitative analysis of mixtures.Crystal Data is a compilation now in the third edition made at the National Bureau of Standards and published by the Joint Committee on Powder Diffraction Standards. It contains data on the unit cell parameters of over 24,000 phases. These data are arranged by crystal system and axial ratios to simplify identification of phases from unit cell data obtained from Single crystal cameras.Both of these large compilations are also important reference sources for crystallographic information giving structural information and literature references.

A Review of the XRD Data of the Phases Present in the CaO-SrO-CuO System

1992 ◽  
Vol 7 (3) ◽  
pp. 142-148 ◽  
Author(s):  
Brian J. Reardon ◽  
Camden R. Hubbard
Keyword(s):  
Solid Solution ◽  
Ternary System ◽  
Crystal Structures ◽  
Powder Diffraction ◽  
Solid Solution Series ◽  
Powder Diffraction File ◽  
Reference Pattern ◽  
X Ray ◽  
Solution Series ◽  
Xrd Patterns

AbstractX-ray powder patterns for the phases in the CaO-SrO-CuO 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 calculated pattern for each phase, yielding a recommended reference pattern. The simulated powder patterns presented here deal with the phases found within the (Ca,Sr)O, (Ca,Sr)2CuO3, (Ca,Sr)14Cu24O41, (Ca,Sr)CuO2, (Ca,Sr)Cu2O3, and (Ca,Sr)Cu2O2 solid solution series and are recommended for the Powder Diffraction File (PDF).

X-ray powder diffraction study of CuInSeTe

2000 ◽  
Vol 15 (1) ◽  
pp. 65-68 ◽  
Author(s):  
Rashmi ◽  
D. K. Suri
Keyword(s):  
Diffraction Study ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Unit Cell ◽  
Chalcopyrite Structure ◽  
Powder Diffraction Data ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Ray Density

CuInSeTe was synthesized by the melt and anneal technique. The compound crystallized in the chalcopyrite structure having space group I4¯2d with Z=4. Complete X-ray powder diffraction data were obtained and the unit cell parameters a and c, X-ray density and u parameter were calculated. These are a=0.5987(1) nm, c=1.1979(4) nm, Dx=5.96×103kg/m3, and u=0.2498. Atomic positions in the unit cell are proposed.© 2000 International Centre for Diffraction Data.

Laboratory Note. A LOTUS 1-2-3 Spreadsheet to Aid in Data Reduction for Publication of X-Ray Powder Diffraction Data

1988 ◽  
Vol 3 (1) ◽  
pp. 39-40 ◽  
Author(s):  
Gregory J. McCarthy
Keyword(s):  
Powder Diffraction ◽  
Diffraction Data ◽  
Data Reduction ◽  
Unit Cell ◽  
Powder Diffraction Data ◽  
Powder Diffraction File ◽  
Mathematical Functions ◽  
X Ray ◽  
Cell Parameters ◽  
Laboratory Note

My students and I have developed a LOTUS 1-2-3 spreadsheet to aid in data reduction tasks associated with preparing powder diffraction data for publication in the Powder Diffraction File (PDF) (1987) and this journal. Portions of a sample spreadsheet and the formulae in each of the computational cells are given in the Table 1. The concept of this spreadsheet should apply to any of the available computer spreadsheet programs, although the specific codes for the mathematical functions may differ.The user enters data only into columns C, D and F-H. All other entries will be calculated from the input data. Observed 2θ angles are entered into column D. The corresponding d-spacing is calculated in column A. The Miller indices of these peaks are entered into column C. Prior to use of the spreadsheet, the observed 2θ angles and hkl's had been used to refine unit cell parameters using the Appleman and Evans (1973) least squares unit cell parameter refinement computer program implemented for the IBM PC by Garvey (1986).

Crystal data of Nitrofurantoin C8H6N4O5

1993 ◽  
Vol 8 (2) ◽  
pp. 107-108 ◽  
Author(s):  
G. Bandoli ◽  
A. Ongaro ◽  
F. Lotto ◽  
M. Rossi
Keyword(s):  
Diffraction Analysis ◽  
Powder Diffraction ◽  
Unit Cell ◽  
Crystal Data ◽  
Unit Cell Parameters ◽  
Powder Diffraction File ◽  
X Ray ◽  
Cell Parameters ◽  
Cell Dimensions ◽  
Unit Cell Dimensions

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.

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