scholarly journals Anomalous Thermal Expansion of HoCo0.5Cr0.5O3 Probed by X-ray Synchrotron Powder Diffraction

2017 ◽  
Vol 12 (1) ◽  
Author(s):  
Vasyl Hreb ◽  
Leonid Vasylechko ◽  
Vitaliya Mykhalichko ◽  
Yurii Prots
Keyword(s):  
Thermal Expansion ◽  
Powder Diffraction ◽  
X Ray ◽  
Synchrotron Powder Diffraction ◽  
Anomalous Thermal Expansion

Thermal expansion of deuterated monoclinic natrojarosite; a combined neutron–synchrotron powder diffraction study

2017 ◽  
Vol 50 (2) ◽  
pp. 340-348
Author(s):  
Helen E. A. Brand ◽  
Nicola V. Y. Scarlett ◽  
Kevin S. Knight
Keyword(s):  
Hydrogen Bond ◽  
Thermal Expansion ◽  
Neutron Diffraction ◽  
Powder Diffraction ◽  
Unit Cell Volume ◽  
Ambient Pressure ◽  
Hydrogen Bond Network ◽  
X Ray ◽  
Synchrotron Powder Diffraction ◽  
Bond Network

A combination of time-of-flight neutron diffraction and synchrotron X-ray powder diffraction has been used to investigate the thermal expansion of a synthetic deuterated natrojarosite from 80 to 440 K under ambient-pressure conditions. The variation in unit-cell volume for monoclinic jarosite over this temperature range can be well represented by an Einstein expression of the form V = 515.308 (5) + 8.5 (4)/{exp[319 (4)/T] − 1}. Analysis of the behaviour of the polyhedra and hydrogen-bond network suggests that the strength of the hydrogen bonds connected to the sulfate tetrahedra is instrumental in determining the expansion of the structure, which manifests primarily in the c-axis direction.

The crystal structure and thermal expansion of the CCl4 adduct of Dianin's compound

1990 ◽  
Vol 68 (8) ◽  
pp. 1352-1356 ◽  
Author(s):  
Walter Abriel ◽  
André Du Bois ◽  
Marek Zakrzewski ◽  
Mary Anne White
Keyword(s):  
Crystal Structure ◽  
Thermal Expansion ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
X Ray Diffraction ◽  
Guest Molecules ◽  
X Ray ◽  
Thermal Expansion Coefficients ◽  
Expansion Coefficients ◽  
Dianin's Compound

The crystal structure of the title compound has been determined by single crystal X-ray diffraction data collected at 293 K, and refined to a final Rw of 0.057. The crystals are rhombohedral, space group [Formula: see text], with a = 27.134(8) Å, c = 10.933(2) Å, and Z = 18. The mole ratio of Dianin's compound (4-p-hydroxyphenyl-2,2,4-trimethylchroman) to CCl4 is 6:1. The guest molecules are disordered. X-ray powder diffraction was carried out in the temperature range from 10 to 300 K. From this, the thermal expansion coefficients for the a- and c-axes and the volume have been determined. Keywords: thermal expansion, crystal structure, clathrate.

Thermal expansion of CaIrO3 determined by X-ray powder diffraction

2007 ◽  
Vol 162 (1-2) ◽  
pp. 140-148 ◽  
Author(s):  
Alex Lindsay-Scott ◽  
Ian G. Wood ◽  
David P. Dobson
Keyword(s):  
Thermal Expansion ◽  
Powder Diffraction ◽  
X Ray

scholarly journals Thermal expansion of kyanite at ambient pressure: An X-ray powder diffraction study up to 1000 °C

2010 ◽  
Vol 1 (1) ◽  
pp. 91-97 ◽  
Author(s):  
Xi Liu ◽  
Qiang He ◽  
Hejing Wang ◽  
Michael E. Fleet ◽  
Xiaomin Hu
Keyword(s):  
Thermal Expansion ◽  
Diffraction Study ◽  
Powder Diffraction ◽  
Ambient Pressure ◽  
X Ray

High-pressure properties of TiP2O7, ZrP2O7and ZrV2O7

2001 ◽  
Vol 34 (1) ◽  
pp. 7-12 ◽  
Author(s):  
Stefan Carlson ◽  
Anne Marie Krogh Andersen
Keyword(s):  
High Pressure ◽  
Thermal Expansion ◽  
Powder Diffraction ◽  
Ambient Pressure ◽  
Negative Thermal Expansion ◽  
X Ray ◽  
Reversible Transition

High-pressure synchrotron X-ray powder diffraction studies of TiP2O7, ZrP2O7and ZrV2O7have been performed. The ZrV2O7structure undergoes a reversible transition at 1.38–1.58 GPa from cubic α- to pseudo-tetragonal β-ZrV2O7that displays an orthorhombic 2 × 3 × 3 supercell. At pressures above 4 GPa, ZrV2O7becomes irreversibly X-ray amorphous. No such transformations are observed for TiP2O7and ZrP2O7, which compress smoothly up to the highest investigated pressures (40.3 and 20.5 GPa, respectively). These differences in high-pressure properties are discussed in terms of the negative thermal expansion of ZrV2O7. The bulk moduli at ambient pressure (B0) for TiP2O7, ZrP2O7, α-ZrV2O7and β-ZrV2O7were estimated to be 42 (3), 39 (1), 17.0 (7) and 20.8 (10) GPa, respectively.

SiBr4 – prediction and determination of crystal structures

2009 ◽  
Vol 65 (3) ◽  
pp. 342-349 ◽  
Author(s):  
Alexandra K. Wolf ◽  
Jürgen Glinnemann ◽  
Martin U. Schmidt ◽  
Jianwei Tong ◽  
Robert E. Dinnebier ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Powder Diffraction ◽  
Global Minimum ◽  
Lattice Energy ◽  
Field Methods ◽  
X Ray ◽  
Β Phase ◽  
Α Phase ◽  
Synchrotron Powder Diffraction

For SiBr4 no crystal structures have been reported yet. In this work the crystal structures of SiBr4 were predicted by global lattice-energy minimizations using force-field methods. Over an energy range of 5 kJ mol−1 above the global minimum ten possible structures were found. Two of these structures were experimentally determined from X-ray synchrotron powder diffraction data: The low-temperature β phase crystallizes in P21/c, the high-temperature α phase in Pa\overline{3}. Temperature-dependant X-ray powder diffraction shows that the phase transition occurs at 168 K.

New Applications of Electron Diffraction in the Pharmaceutical Industry: Polymorph Determination by Using a Combination of Electron Diffraction and Synchrotron X-ray Powder Diffraction Techniques

2002 ◽  
Vol 8 (2) ◽  
pp. 134-138 ◽  
Author(s):  
Z.G. Li ◽  
R.L. Harlow ◽  
C.M. Foris ◽  
H. Li ◽  
P. Ma ◽  
...  
Keyword(s):  
Pharmaceutical Industry ◽  
Electron Diffraction ◽  
Powder Diffraction ◽  
Unit Cell ◽  
X Ray ◽  
Cell Parameters ◽  
Synchrotron Powder Diffraction ◽  
Transmission Electron ◽  
Diffraction Patterns ◽  
New Applications

Electron diffraction has been recently used in the pharmaceutical industry to study the polymorphism in crystalline drug substances. While conventional X-ray diffraction patterns could not be used to determine the cell parameters of two forms of the microcrystalline GP IIb/IIIa receptor antagonist roxifiban, a combination of electron single-crystal and synchrotron powder diffraction techniques were able to clearly distinguish the two polymorphs. The unit-cell parameters of the two polymorphs were ultimately determined using new software routines designed to take advantage of each technique's unique capabilities. The combined use of transmission electron microscopy (TEM) and synchrotron patterns appears to be a good general approach for characterizing complex (low-symmetry, large-unit-cell, micron-sized) polymorphic pharmaceutical compounds.

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