The lattice parameters and interplanar spacings of some artificially prepared melilites

1948 ◽  
Vol 28 (202) ◽  
pp. 374-379 ◽  
Author(s):  
K. W. Andrews
Keyword(s):  
Crystal Structure ◽  
Blast Furnace ◽  
Binary System ◽  
Laboratory Investigation ◽  
Solid Solutions ◽  
Lattice Parameters ◽  
Refractive Indices ◽  
X Ray ◽  
Tetragonal Lattice ◽  
Intermediate Series

A laboratory investigation in connexion with some blast-furnace slags, led to the preparation of the five synthetic melilites for which X-ray data are provided. The five compounds represent gehlenite, åkermanite and three members of the intermediate series of solid solutions, corresponding to 25, 50, and 75 % of åkermanite.The binary system gehlenite–åkermanite was studied by Ferguson and Buddington, who established relationships between refractive indices, density, and composition and determined solidus and liquidus curves. The crystal structure of the melilite group of compounds was investigated by Warren, who showed that the structure was based on a tetragonal lattice.

Phase diagram of the Nd2Fe14B–Sm2Fe14B pseudo-binary system

2016 ◽  
Vol 49 (1) ◽  
pp. 64-68 ◽  
Author(s):  
Ch. F. Xu ◽  
K. H. Chen ◽  
Z. F. Gu ◽  
L. Y. Cheng ◽  
D. D. Ma ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Phase Diagram ◽  
Binary System ◽  
Solid Solutions ◽  
Structure Parameters ◽  
Rietveld Refinements ◽  
X Ray ◽  
Full Profile ◽  
Cell Volumes ◽  
Scanning Electron

The phase relations in the (1−x)Nd2Fe14B–xSm2Fe14B system over the whole concentration range have been studied by means of X-ray powder diffraction (XRD), differential thermal analysis (DTA) and scanning electron microscopy with energy-dispersive X-ray spectroscopy. Crystal structure parameters for all studied compositions of (Nd1−xSmx)2Fe14B have been determined by full-profile Rietveld refinements. These results revealed that all intermediate alloys of (Nd1−xSmx)2Fe14B are similar to the end member of the investigated system, Nd2Fe14B, with a tetragonal structure (space groupP42/mnm). The formation of continuous solid solutions has been found in this system. The normalized lattice parameters and unit-cell volumes of (Nd1−xSmx)2Fe14B solid solutions decrease linearly with increasing Sm content. The DTA measurements show that the melting temperature of (Nd1−xSmx)2Fe14B increases linearly with increasing Sm content and no metastable phases were detected. Based on the DTA data and XRD results, a tentative phase diagram for the pseudo-binary system Nd2Fe14B–Sm2Fe14B has been constructed.

X-ray study of CuGa x In1−x Se2 solid solutions

1989 ◽  
Vol 22 (6) ◽  
pp. 578-583 ◽  
Author(s):  
D. K. Suri ◽  
K. C. Nagpal ◽  
G. K. Chadha
Keyword(s):  
Solid Solution ◽  
Binary System ◽  
Crystallite Size ◽  
Solid Solutions ◽  
Lattice Parameters ◽  
Chalcopyrite Structure ◽  
Space Group ◽  
X Ray ◽  
Structure Space ◽  
A Value

The semiconducting compound CuGa x In1 − x Se2 crystallizes in the chalcopyrite structure (space group I{\bar 4}2d, Z = 4). The X-ray powder data for x = 1, 0.75, 0.6, 0.5, 0.4, 0.25 and 0.0 have been collected and it is found that the lattice parameters a and c and their ratio c/a vary linearly with x. Thus the composition of any chalcopyrite in the pseudo-binary system CuGaSe2 and CuInSe2 can be obtained from the accurate lattice parameters. The crystallite size determined from the (112) plane is minimum for x = 0.50 (~ 1000 Å) and away from x = 0.50 it increases. A value of u = 0.240 (5) has been established for fixing the Se-atom positions in the CuGa0.5In0.5Se2 solid solution. The JCPDS Diffraction File No. for CuInSe2 is 40-1487 and for CuGa0.5In0.5Se2 is 40-1488.

The Quasi-Binary System CeCoC2-CeNiC2: Crystal Structure and Physical Properties

2019 ◽  
Vol 289 ◽  
pp. 114-119
Author(s):  
Herwig Michor ◽  
Alexander Schumer ◽  
Mykola Hembara ◽  
Bogdan Kotur ◽  
Volodymyr Levytskyy ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Binary System ◽  
Powder Diffraction ◽  
Solid Solutions ◽  
Ground State ◽  
Kondo Lattice ◽  
Type Structure ◽  
Intermediate Region ◽  
X Ray ◽  
Quasi Binary System

The crystal structure of phases in the pseudo-binary system CeCo1–хNiхC2 (x = 0, 0.33, 0.5, 0.67, 0.79, 0.80, 0.83, 1) was investigated by means of X-ray powder diffraction. Co richer solid solutions CeCo1–хNiхC2 (0≤ x ≤0.5) crystallize in the monoclinic CeCoC2-type structure; a = 5.3968(2) Å, b = 5.4013(3) Å, c = 7.4762(3) Å, β = 102.136(3)°, V = 213.06(3) Å3 for x = 0.5. Ni-rich CeNi1–yCoyC2 (0≤ y ≤0.2) are isotypic with the orthorhombic CeNiC2-type structure, a = 3.8486(2) Å, b = 4.5479(2) Å, c = 6.1531(3) Å, V = 107.70(1) Å3 for y = 0.2. In the intermediate region (0.5< x <0.79) both phases, CeCo0.21Ni0.79C2 and CeCo0.5Ni0.5C2, coexist. The non-isoelectronic substitution of Ni by Co in solid solutions CeNi1–yCoyC2 causes a continuous reduction of the Néel temperature and finally, for CeCoC2, results in a paramagnetic Kondo-lattice ground state.

Single-crystal investigation of Ce5AgxGe4−x (x = 0.1−1.08) with Sm5Ge4 type

2020 ◽  
Vol 75 (8) ◽  
pp. 765-768
Author(s):  
Bohdana Belan ◽  
Dorota Kowalska ◽  
Mariya Dzevenko ◽  
Mykola Manyako ◽  
Roman Gladyshevskii
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Diffraction Data ◽  
Binary Compound ◽  
Lattice Parameters ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray

AbstractThe crystal structure of the phase Ce5AgxGe4−x (x = 0.1−1.08) has been determined using single-crystal X-ray diffraction data for Ce5Ag0.1Ge3.9. This phase is isotypic with Sm5Ge4: space group Pnma (No. 62), Pearson code oP36, Z = 4, a = 7.9632(2), b = 15.2693(5), c = 8.0803(2) Å; R1 = 0.0261, wR2 = 0.0460, 1428 F2 values and 48 variables. The two crystallographic positions 8d and 4c show Ge/Ag mixing, leading to a slight increase in the lattice parameters as compared to those of the pure binary compound Ce5Ge4.

scholarly journals β-Y(BO2)3 – a new member of the β-Ln(BO2)3 (Ln=Nd, Sm, Gd–Lu) structure family

2017 ◽  
Vol 72 (12) ◽  
pp. 983-988 ◽  
Author(s):  
Martin K. Schmitt ◽  
Hubert Huppertz
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Lattice Parameters ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
X Ray

Abstractβ-Y(BO2)3 was synthesized in a Walker-type multianvil module at 5.9 GPa/1000°C. The crystal structure has been elucidated through single-crystal X-ray diffraction. β-Y(BO2)3 crystallizes in the orthorhombic space group Pnma (no. 62) with the lattice parameters a=15.886(2), b=7.3860(6), and c=12.2119(9) Å. Its crystal structure will be discussed in the context of the isotypic lanthanide borates β-Ln(BO2)3 (Ln=Nd, Sm, Gd–Lu).

scholarly journals Magnetically Oriented Powder Crystal to Indexing and Structure Determination

2014 ◽  
Vol 70 (a1) ◽  
pp. C1560-C1560
Author(s):  
Fumiko Kimura ◽  
Wataru Oshima ◽  
Hiroko Matsumoto ◽  
Hidehiro Uekusa ◽  
Kazuaki Aburaya ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Crystal Lattice ◽  
Powder Diffraction ◽  
Diffraction Method ◽  
Lattice Parameters ◽  
X Ray Diffraction ◽  
X Ray ◽  
Crystal Lattice Parameters

In pharmaceutical sciences, the crystal structure is of primary importance because it influences drug efficacy. Due to difficulties of growing a large single crystal suitable for the single crystal X-ray diffraction analysis, powder diffraction method is widely used. In powder method, two-dimensional diffraction information is projected onto one dimension, which impairs the accuracy of the resulting crystal structure. To overcome this problem, we recently proposed a novel method of fabricating a magnetically oriented microcrystal array (MOMA), a composite in which microcrystals are aligned three-dimensionally in a polymer matrix. The X-ray diffraction of the MOMA is equivalent to that of the corresponding large single crystal, enabling the determination of the crystal lattice parameters and crystal structure of the embedded microcrytals.[1-3] Because we make use of the diamagnetic anisotropy of crystal, those crystals that exhibit small magnetic anisotropy do not take sufficient three-dimensional alignment. However, even for these crystals that only align uniaxially, the determination of the crystal lattice parameters can be easily made compared with the determination by powder diffraction pattern. Once these parameters are determined, crystal structure can be determined by X-ray powder diffraction method. In this paper, we demonstrate possibility of the MOMA method to assist the structure analysis through X-ray powder and single crystal diffraction methods. We applied the MOMA method to various microcrystalline powders including L-alanine, 1,3,5-triphenyl benzene, and cellobiose. The obtained MOMAs exhibited well-resolved diffraction spots, and we succeeded in determination of the crystal lattice parameters and crystal structure analysis.

Powder X-ray diffraction study of disilver(1+) pentacyanonitrosylferrate(2−)

1999 ◽  
Vol 14 (3) ◽  
pp. 219-221 ◽  
Author(s):  
V. Venegas ◽  
A. Gómez ◽  
E. Reguera
Keyword(s):  
Crystal Structure ◽  
Thermogravimetric Analysis ◽  
Diffraction Study ◽  
Powder Diffraction ◽  
Lattice Parameters ◽  
X Ray Diffraction ◽  
Density Measurements ◽  
X Ray

The crystal structure of disilver(1+) pentacyanonitrosylferrate(2−) was studied by X-ray powder diffraction. IR and Mössbauer spectroscopies, thermogravimetric analysis and density measurements were also carried out. This compound is monoclinic, and its lattice parameters are: a=10.986(3) Å, b=6.4080(10) Å, c=7.4545(19) Å, α=δ=90°, β=102.54°(2).

X-ray Diffraction Studies of Solid Solutions of Pentaglycerine-Neopentylglycol

1988 ◽  
Vol 32 ◽  
pp. 609-616 ◽  
Author(s):  
D. Chandra ◽  
C. S. Barrett ◽  
D. K. Benson
Keyword(s):  
Crystal Structure ◽  
Energy Storage ◽  
Hydrogen Bonds ◽  
Solid Solutions ◽  
Room Temperature ◽  
Energy Storage Materials ◽  
Anisotropic Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cubic Structure

AbstractAn array of molecules that is anisotropic in the extreme has been discovered in certain thermal-energy storage materials and is reported here: neopentylglycol (NPG) and NPG-rich solid solutions with pentaglycerine (PG) have a crystal structure, stable at room temperature, that consists of bimolecular chains of molecules that are all unidirectionally aligned throughout a crystal. There are hydrogen bonds between every molecule in one chain and its neighbors in that chain, but none between molecules of one chain and any molecules of the neighboring parallel chains. Thus there are strong intermolecular bonds along each chain and only weaker bonds between the chains. The structure has been determined by using modern single crystal techniques with 529 independent reflections from a crystal of NPG (C5H12O2). The structure is monoclinic with space group P21/c - C2h5. This anisotropic structure transforms to a cubic structure at higher temperatures.

High-temperature X-ray powder diffraction study of the tetragonal-cubic phase transition in nanocrystalline, compositionally homogeneous ZrO2–CeO2 solid solutions

2008 ◽  
Vol 23 (S1) ◽  
pp. S70-S74 ◽  
Author(s):  
L. M. Acuña ◽  
R. O. Fuentes ◽  
D. G. Lamas ◽  
I. O. Fábregas ◽  
N. E. Walsöe de Reca ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
High Temperature ◽  
Powder Diffraction ◽  
Solid Solutions ◽  
Tetragonal Phase ◽  
Room Temperature ◽  
Cubic Phase ◽  
X Ray ◽  
First Order

Crystal structure of compositionally homogeneous, nanocrystalline ZrO2–CeO2 solutions was investigated by X-ray powder diffraction as a function of temperature for compositions between 50 and 65 mol % CeO2. ZrO2-50 and 60 mol % CeO2 solid solutions, which exhibit the t′-form of the tetragonal phase at room temperature, transform into the cubic phase in two steps: t′-to-t″ followed by t″-to-cubic. But the ZrO2-65 mol % CeO2, which exhibits the t″-form, transforms directly to the cubic phase. The results suggest that t′-to-t″ transition is of first order, but t″-to-cubic seems to be of second order.

Kristall- und Molekülstruktur von 5.10-Dihydro-5.10-diniethylphenaziniiimtniodid und 5.10-Dihydro-5.10-diethylphenaziniumtriiodid / Molecular and Crystal Structure of 5,10-Dihydro-5.10-dimethylphenaziniumtriiodide and 5.10-Dihydro-5.10-diethylphenazinium triiodide

1978 ◽  
Vol 33 (8) ◽  
pp. 838-842 ◽  
Author(s):  
H. J. Keller ◽  
W. Moroni ◽  
D. Nöthe ◽  
M. Scherz ◽  
J. Weiss
Keyword(s):  
Crystal Structure ◽  
Radical Cations ◽  
Unit Cell ◽  
Lattice Parameters ◽  
Molecular And Crystal Structure ◽  
Reaction Conditions ◽  
Space Group ◽  
X Ray ◽  
R Value

Oxidation of 5,10-dihydro-5,10-dimethylphenazine and 5,10-dihydro-5,10-diethyl-phenazine under different reaction conditions leads to several iodine containing solids. The preparation and X-ray structure of two of them, 5,10-dihydro-5,10-dimethyl-phcnaziniumtriiodide (3) and 5,10-dihydro-5,10-diethylphenaziniumtriiodido (4) are reported here.Compound 3 crystallizes in space group P21/n with lattice parameters a = 8.552(6) Å, b= 16.953(2) Å, c- 12.157(9) Å and β= 103.46(2)° with four formula units in the unit cell. The structure was refined to an R-value of 0.046 using 2387 independent reflections. The lattice constains distinct, slightly distorted triiodide ions and bent 5,10-dihydro-5,10-dimethylphenazinium radical cations. Compound 4 crystallizes in the same space group P21/n with lattice parameters a = 8.531(6) Å, b = 8.332(21) Å, c = 13.320(15) Å and β= 94.44(19)° with two formula units in the unit cell. The structure was refined to an R-value of 0.076 using 1195 independent reflections. The lattice contains strictly linear symmetrical triiodide ions and planar centrosymmetrical 5,10-dihydro-5,10-diethyl- phenazinium radical cations.

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