Notizen: Vibrational Excess Entropy of Equimolar KCl—KBr Solid Solution

1970 ◽  
Vol 25 (11) ◽  
pp. 1761-1762 ◽  
Author(s):  
M. Ahtee ◽  
A. Pesonen ◽  
P. Salmo ◽  
O. Inkinen
Keyword(s):  
Solid Solution ◽  
Diffraction Data ◽  
Excess Entropy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ideal Mixing

Abstract The Debye-Waller factors of the ions in equimolar KCl — KBr solid solution at 300 K have been determined from X-ray diffraction data. It was observed that the amplitudes of ther-mal vibration are slightly higher in the solid solution than in the pure components. The corresponding vibrational excess entropy was found to be about 10% of the entropy of ideal mixing.

Superstructure formation in the solid solution Sc3Pt3−xIn3 (x = 0–0.93)

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Nataliya L. Gulay ◽  
Rolf-Dieter Hoffmann ◽  
Jutta Kösters ◽  
Yaroslav M. Kalychak ◽  
Stefan Seidel ◽  
...  
Keyword(s):  
Solid Solution ◽  
Diffraction Data ◽  
High Frequency ◽  
Lattice Parameters ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Platinum Content ◽  
Arc Melting ◽  
Modulation Vector

Abstract The equiatomic indide ScPtIn (ZrNiAl type, space group P 6 ‾ $‾{6}$ 2m) shows an extended solid solution Sc3Pt3–xIn3. Several samples of the Sc3Pt3–xIn3 series were synthesized from the elements by arc-melting and subsequent annealing, or directly in a high frequency furnace. The lowest platinum content was observed for Sc3Pt2.072(3)In3. All samples were characterized by powder X-ray diffraction and their lattice parameters and several single crystals were studied on the basis of precise single crystal X-ray diffractometer data. The correct platinum occupancy parameters were refined from the diffraction data. Decreasing platinum content leads to decreasing a and c lattice parameters. Satellite reflections were observed for the Sc3Pt3–xIn3 crystals with x = 0.31–0.83. These satellite reflections could be described with a modulation vector ( 1 3 , 1 3 , γ ) $\left(\frac{1}{3},\frac{1}{3},\gamma \right)$ ( γ = 1 2 $\gamma =\frac{1}{2}$ c* for all crystals) and are compatible with trigonal symmetry. The interplay of platinum filled vs. empty In6 trigonal prisms is discussed for an approximant structure with space group P3m1.

X-Ray Diffraction Investigation of the Sn-Hg Phase in Dental Amalgam*

1961 ◽  
Vol 5 ◽  
pp. 64-70 ◽  
Author(s):  
Carl W. Fairhurst ◽  
Gunnar Ryge
Keyword(s):  
Solid Solution ◽  
Diffraction Data ◽  
Least Squares Method ◽  
Cell Structure ◽  
Dental Amalgam ◽  
Filling Material ◽  
X Ray Diffraction ◽  
Hexagonal Symmetry ◽  
X Ray ◽  
Unit Cell Structure

AbstractDental amalgam has been used as a filling material in dentistry for over 100 years. The reactants, Ag3Sn alloy and mercury, form silver-mercury and tin-mercury products. Previous X-ray diffraction studies have resulted in some disagreement concerning unit-cell structure and parameters of the products. In this study, X-ray diffraction measurements were carried out on tin-mercury mixtures, tin-mercury alloys, dental amalgam, and single crystals of tin and mercury. The diffraction data for the tin-mercury alloys were programed for an IBM 650 computer utilizing Cohen's least-squares method. The tin-mercury product was found to be a solid solution possessing hexagonal-symmetry elements. The parameters ranged from: c0 = 2.995 A to 2.984 A, co/ao = 0.931.

The Solid Solution Lu2–xScxSiO5

2011 ◽  
Vol 66 (11) ◽  
pp. 1183-1187
Author(s):  
Hamdi Ben Yahia ◽  
Ute Ch. Rodewald ◽  
Birgit Heying ◽  
Sarkarainadar Balamurugan ◽  
Rainer Pöttgen
Keyword(s):  
Solid Solution ◽  
Rare Earth ◽  
Single Crystal ◽  
Diffraction Data ◽  
Strong Preference ◽  
X Ray Diffraction ◽  
X Ray ◽  
Type Space ◽  
Coordination Numbers ◽  
Oxygen Coordination

The monoclinic silicates Lu2SiO5 and Sc2SiO5 (Y2SiO5 type, space groupC2/c) forma solid solution Lu2−xScxSiO5. Samples with x = 0.5, 0.8, 1.0 were synthesized ceramically from Lu2O3, Sc2O3, and SiO2. The structures of three crystals with x = 0.88, 0.77, and 0.50 were refined on the basis of single-crystal X-ray diffraction data. The rare earth (RE) atoms occupy two crystallographically different 8ƒ sites with oxygen coordination numbers (CN) of 6 (RE2) and 7 (RE1). Refinements of the occupancy parameters showed Lu/Sc mixing for both sites with a strong preference of the smaller scandium atoms for CN6

X-RAY DIFFRACTION STUDY ON THE CRYSTAL STRUCTURE OF Sm1+xBa2−xCu3O7−y

1988 ◽  
Vol 02 (02) ◽  
pp. 583-588 ◽  
Author(s):  
H. ASANO ◽  
Y. YOKOYAMA ◽  
M. NISHINO ◽  
H. KATOH ◽  
H. AKINAGA ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Solid Solution ◽  
Diffraction Study ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Rietveld Analysis ◽  
Powder Diffraction Data ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure Changes

Crystal structures in solid solution of Sm 1+x Ba 2−x Cu 3 O 7−y (X = 0 - 0.4) have been investigated by Rietveld analysis of X-ray powder diffraction data. The structure changes from orthorhombic to tetragonal at x=0.2. With the increase of x, Tc decreases monotonically from 90 K and the compound becomes semiconducting at x=0.4.

scholarly journals Оптические и структурные свойства эпитаксиальных слоев Hg-=SUB=-0.7-=/SUB=-Cd-=SUB=-0.3-=/SUB=-Te

2021 ◽  
Vol 55 (11) ◽  
pp. 1040
Author(s):  
Д.А. Андрющенко ◽  
М.С. Ружевич ◽  
А.М. Смирнов ◽  
Н.Л. Баженов ◽  
К.Д. Мынбаев ◽  
...  
Keyword(s):  
Solid Solution ◽  
Optical Properties ◽  
Diffraction Data ◽  
Epitaxial Films ◽  
Structural Quality ◽  
Bulk Crystals ◽  
X Ray Diffraction ◽  
X Ray ◽  
Photoluminescence Studies

The results of comparative studies of the optical and structural properties of Hg0.7Cd0.3Te bulk crystals and epitaxial films grown by various methods are presented. The data of photoluminescence studies performed in the temperature range 4.2−300K showed the similarity of the optical properties of different samples and indicated a significant disordering of the solid solution. According to X-ray diffraction data, however, the scale of the disordering was not directly related to the structural quality of the material. The prospects for using the material grown by various methods in optoelectronics applications are discussed.

The Yttrium Oxide Fluoride Solid Solution Described as a Composite Modulated System

1998 ◽  
Vol 54 (4) ◽  
pp. 391-398 ◽  
Author(s):  
S. Schmid
Keyword(s):  
Solid Solution ◽  
Yttrium Oxide ◽  
Diffraction Data ◽  
Substantial Reduction ◽  
Lattice Parameters ◽  
Group Symmetry ◽  
X Ray Diffraction ◽  
Modulated Structure ◽  
X Ray ◽  
Wide Range

Single-crystal X-ray diffraction data (Mo Kα radiation) are used to determine the structure of the Δ = 0.174 member of a (YO1 − ΔFΔ)F1 + Δ, 0.12 ≤ Δ ≤ 0.22, wide-range non-stoichiometric solid solution in the yttrium oxide fluoride system. The structure is refined as a composite modulated structure composed of two mutually incommensurable Q and H substructures with overall superspace-group symmetry Acmm(0,0,1.174..)0s0. The Q substructure has lattice parameters a = 5.415 (2), bQ = 5.534 (2) and cQ = 5.525 (2) Å, and superspace-group symmetry Acmm(0,0,1.174..)0s0. The H substructure has lattice parameters a = 5.415 (2), bH = 1/2bQ = 2.767 (1) and cH  = 4.696 (2) Å, and superspace-group symmetry Pmcm(0,1/2,0.8518...)s00. Refinement on 338 unique reflections converged to R = 0.025, while a previous conventional superstructure refinement led to R = 0.101. This lowering of the R factor goes hand-in-hand with a substantial reduction in the number of refined parameters.

scholarly journals High-pressure synthesis and crystal structure of the mixed-cation borate Ga4In4B15O33(OH)3

2019 ◽  
Vol 74 (4) ◽  
pp. 357-363
Author(s):  
Daniela Vitzthum ◽  
Hubert Huppertz
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
High Temperature ◽  
Diffraction Data ◽  
X Ray Diffraction ◽  
Synthesis And Crystal Structure ◽  
X Ray ◽  
Mixed Cation ◽  
High Pressure High Temperature ◽  
Pressure Synthesis

AbstractThe mixed cation triel borate Ga4In4B15O33(OH)3 was synthesized in a Walker-type multianvil apparatus at high-pressure/high-temperature conditions of 12.5 GPa and 1300°C. Although the product could not be reproduced in further experiments, its crystal structure could be reliably determined via single-crystal X-ray diffraction data. Ga4In4B15O33(OH)3 crystallizes in the tetragonal space group I41/a (origin choice 2) with the lattice parameters a = 11.382(2), c = 15.244(2) Å, and V = 1974.9(4) Å3. The structure of the quaternary triel borate consists of a complex network of BO4 tetrahedra, edge-sharing InO6 octahedra in dinuclear units, and very dense edge-sharing GaO6 octahedra in tetranuclear units.

Crystallization and preliminary x-ray diffraction data of the cryptomonad biliprotein phycocyanin-645 from a Chroomonas spec.

1984 ◽  
Vol 140 (2-3) ◽  
pp. 202-205 ◽  
Author(s):  
Walter Morisset ◽  
Werner Wehrmeyer ◽  
Tilman Schirmer ◽  
Wolfram Bode
Keyword(s):  
Diffraction Data ◽  
X Ray Diffraction ◽  
X Ray

Theoretically derived thermodynamic properties can be improved by the refinement of low-frequency modes against X-ray diffraction data

2021 ◽  
Author(s):  
Anna Agnieszka Hoser ◽  
Marcin Sztylko ◽  
Damian Trzybiński ◽  
Anders Østergaard Madsen
Keyword(s):  
Thermodynamic Properties ◽  
Dft Calculations ◽  
Diffraction Data ◽  
Molecular Crystals ◽  
Low Frequency ◽  
X Ray Diffraction ◽  
X Ray ◽  
Efficient Approach

A framework for estimation of thermodynamic properties for molecular crystals via refinement of frequencies from DFT calculations against X-ray diffraction data is presented. The framework provides an efficient approach to...

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