The Use of Quartz as an Internal Pressure Standard in High-Pressure Crystallography

1997 ◽  
Vol 30 (4) ◽  
pp. 461-466 ◽  
Author(s):  
R. J. Angel ◽  
D. R. Allan ◽  
R. Miletich ◽  
L. W. Finger
Keyword(s):  
High Pressure ◽  
Equation Of State ◽  
Order Equation ◽  
Unit Cell ◽  
Unit Cell Parameters ◽  
Third Order ◽  
Single Crystal Diffraction ◽  
Cell Parameters ◽  
Diamond Anvil ◽  
Pressure Standard

The unit-cell parameters of quartz, SiO2, have been determined by single-crystal diffraction at 22 pressures to a maximum pressure of 8.9 GPa (at room temperature) with an average precision of 1 part in 9000. Pressure was determined by the measurement of the unit-cell volume of CaF2 fluorite included in the diamond-anvil pressure cell. The variation of quartz unit-cell parameters with pressure is described by: a −4.91300 (11) = −0.0468 (2) P + 0.00256 (7) P 2 − 0.000094 (6) P 3, c − 5.40482 (17) = − 0.03851 (2) P + 0.00305 (7) P 2 − 0.000121 (6) P 3, where P is in GPa and the cell parameters are in ångstroms. The volume–pressure data of quartz are described by a Birch–Murnaghan third-order equation of state with parameters V 0 = 112.981 (2) å3, K T0 = 37.12 (9) GPa and K′ = 5.99 (4). Refinement of K′′ in a fourth-order equation of state yielded a value not significantly different from the value implied by the third-order equation. The use of oriented quartz single crystals is proposed as an improved internal pressure standard for high-pressure single-crystal diffraction experiments in diamond-anvil cells. A measurement precision of 1 part in 10 000 in the volume of quartz leads to a precision in pressure measurement of 0.009 GPa at 9 GPa.

High-pressure studies of three polymorphs of a palladium(II) oxathioether macrocyclic complex

2016 ◽  
Vol 72 (3) ◽  
pp. 357-371 ◽  
Author(s):  
Jeremiah P. Tidey ◽  
Henry L. S. Wong ◽  
Jonathan McMaster ◽  
Martin Schröder ◽  
Alexander J. Blake
Keyword(s):  
High Pressure ◽  
Macrocyclic Complex ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Third Order ◽  
X Ray ◽  
Cell Parameters ◽  
Disordered Structure ◽  
High Pressure Studies

The three reported phases of the mononuclear macrocyclic PdIIcomplex [PdCl2([9]aneS2O)] [(1); [9]aneS2O = 1-oxa-4,7-dithiacyclononane] were each studied up to pressures exceeding 9 GPa using high-pressure single-crystal X-ray diffraction. The α- and γ-phases both exhibit smooth compression of the unit-cell parameters with third-order Birch–Murnaghan bulk moduli of 14.4 (8) and 7.6 (6) GPa, respectively. Between 6.81 and 6.87 GPa β-[PdCl2([9]aneS2O)] was found to undergo a reversible transition to a phase denoted as β′ and characterized by a tripling of the unit-cell volume. Across the phase transition, rearrangement of the conformation of the bound macrocycle at two of the resulting three unique sites gives rise to an extensively disordered structure.

XRPD and Scanning Electron Microscopy of Alloys of the CuAlS2 – CuFeS2 System Prepared by Thermobaric Treatment

MRS Advances ◽  
2018 ◽  
Vol 3 (56) ◽  
pp. 3323-3328
Author(s):  
Barys Korzun ◽  
Anatoly Pushkarev
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
High Pressure ◽  
Unit Cell Volume ◽  
Unit Cell ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Lattice Constants ◽  
Scanning Electron

ABSTRACTAlloys of the CuAlS2 – CuFeS2 system were prepared by thermobaric treatment at high pressure of 5.5 GPa and temperatures ranging from 573 to 1573 K and phase formation in the system was investigated using X-ray powder diffraction, optical microscopy and scanning electron microscopy equipped with energy dispersive spectroscopy. The unit-cell parameters (the lattice constants and the unit-cell volume) were computed as a function of the composition. Absence of complete solubility in the (CuAlS2)1-x-(CuFeS2)x system was established. Formation of solid solutions with the tetragonal structure of chalcopyrite was detected for compositions with the molar part of CuFeS2 x not exceeding 0.10.

SINGLE: a program to control single-crystal diffractometers

2010 ◽  
Vol 44 (1) ◽  
pp. 247-251 ◽  
Author(s):  
R. J. Angel ◽  
L. W. Finger
Keyword(s):  
Single Crystal ◽  
Operating Systems ◽  
Unit Cell ◽  
Unit Cell Parameters ◽  
Cell Parameters ◽  
Diamond Anvil

SINGLE, a program that runs under Windows operating systems, can be used to control a variety of four-circle Eulerian-cradle single-crystal diffractometers including Huber instruments equipped with Huber motor controllers, the Stoe Stadi-4 and the Siemens P4. The software can be configured,viavariables set by the user, to operate any of these diffractometers with a variety of environmental devices including furnaces and diamond-anvil pressure cells. It is specifically designed to determine unit-cell parameters to a precision of 1 part in 30 000.

The crystal structure of wolframite type tungstates at high pressure

1993 ◽  
Vol 207 (2) ◽  
Author(s):  
J. Macavei ◽  
H. Schulz
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Standard Deviation ◽  
Diamond Anvil Cell ◽  
Scheelite Structure ◽  
Unit Cell Parameters ◽  
Cell Parameters ◽  
Heavy Atoms ◽  
Structure Determinations ◽  
Diamond Anvil

AbstractSingle-crystal structure determinations of wolframite-type structures were performed using a diamond anvil cell with beryllium gaskets. Unit cell parameters of MgWOAll investigated compounds compress anisotropically with theIn all compounds, the WOWith increasing pressure the oxygen atomic positions remain constant within one standard deviation, while the heavy atoms positions show a different pressure dependence: a shift ofWith increasing pressure the A and W cations approach each other, indicating a tendency of a transition from the wolframite structure to the scheelite structure, where the A and W cations lie in the same plane.

Powder X-ray diffraction data of a new polymorph of HfMo2O8

2003 ◽  
Vol 18 (2) ◽  
pp. 147-149 ◽  
Author(s):  
S. N. Achary ◽  
G. D. Mukherjee ◽  
A. K. Tyagi ◽  
B. K. Godwal
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Diffraction Data ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Lattice Space ◽  
Monoclinic Lattice

A new polymorph of HfMo2O8 (β-form) is synthesized under high pressure and high temperature conditions. The powder X-ray diffraction (XRD) data could be explained based on a monoclinic lattice (Space Group: C2/c No. 15) with the unit cell parameters as: a=11.415(3), b=7.906(2), c=7.438(2) Å and β=122.37(2)°, V=566.9(2) Å3. The detailed powder XRD data and analysis are reported herein.

Powder X-ray diffraction study of a new polymorph of Al2(WO4)3

2006 ◽  
Vol 21 (1) ◽  
pp. 63-66 ◽  
Author(s):  
G. D. Mukherjee ◽  
V. Vijayakumar ◽  
B. K. Godwal ◽  
S. N. Achary ◽  
A. K. Tyagi
Keyword(s):  
High Pressure ◽  
Diffraction Study ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Lattice Space ◽  
Monoclinic Lattice

A new polymorph of Al2(WO4)3 is observed from in situ high pressure powder X-ray diffraction (ADXRD) measurements at 3.4 GPa. The ADXRD pattern at 3.4 GPa could be explained based on a monoclinic lattice (space group P21) with unit cell parameters: a=9.5884(24), b=12.5204(38), c=7.8463(33) Å, and β=91.98(2)°.

scholarly journals Structure and Behavior of the Ni End-Member Schreibersite Ni3P under Compression to 50 GPa

Minerals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 306
Author(s):  
Sasithorn Chornkrathok ◽  
Dongzhou Zhang ◽  
Przemyslaw Dera
Keyword(s):  
Single Crystal ◽  
Diamond Anvil Cell ◽  
Light Element ◽  
Magnetic Ordering ◽  
Binary Compound ◽  
Unit Cell ◽  
Unit Cell Parameters ◽  
Cell Parameters ◽  
Diamond Anvil ◽  
And Behavior

To better understand the potential presence of light element alloys of Fe and Ni in the Earth’s interior, the crystal structure and compressional behavior of the Ni-P binary compound, schreibersite (Ni3P), have been investigated using synchrotron X-ray diffraction experiments. Both powder and two single-crystal samples of synthetic Ni3P (in different orientations with respect to the loading axis of the diamond anvil cell) were compressed up to approximately 50 GPa at ambient temperature. The compressional data obtained for Ni3P were fitted with a 3rd order Birch–Murnaghan equation of state. All data indicated that the c/a ratio of unit cell parameters remained approximately constant up to about 30 GPa but then increased progressively with pressure, exhibiting a second slight discontinuity at approximately 40 GPa. The changes in unit cell parameters at ~30 GPa and ~40 GPa suggested discontinuous changes in magnetic ordering. Moreover, the threshold of these subtle discontinuities is sensitive to the stress state and orientation of the crystal in the diamond anvil cell. This study is the first report on the compressional behavior of both powder and single-crystal schreibersite at high-pressure (up to 50 GPa). It offers insights into the effects of Ni3P components on the compressional behavior of the Earth’s core.

scholarly journals High-pressure crystal chemistry of coesite-I and its transition to coesite-II

2014 ◽  
Vol 229 (11) ◽  
Author(s):  
Ana Černok ◽  
Elena Bykova ◽  
Tiziana Boffa Ballaran ◽  
Hanns-Peter Liermann ◽  
Michael Hanfland ◽  
...  
Keyword(s):  
High Pressure ◽  
Synchrotron Radiation ◽  
Crystal Chemistry ◽  
Diffraction Data ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Diamond Anvil ◽  
Pressure Interval

AbstractThe high-pressure crystal chemistry of coesite was studied by means of single crystal X-ray diffraction in the pressure interval ∼2–34 GPa and at ambient temperature. We compressed the samples using diamond-anvil cells loaded with neon as pressure-transmitting medium and collected X-ray diffraction data using synchrotron radiation. The thermodynamically stable coesite – coesite-I – was observed up to ∼20 GPa, with the following unit-cell parameters:

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