The alunite supergroup under high pressure: the case of natrojarosite, NaFe3(SO4)2(OH)6

2013 ◽  
Vol 77 (7) ◽  
pp. 3007-3017 ◽  
Author(s):  
F. Nestola ◽  
S. J. Mills ◽  
B. Periotto ◽  
L. Scandolo
Keyword(s):  
High Pressure ◽  
Single Crystal ◽  
Maximum Pressure ◽  
X Ray Diffraction ◽  
Third Order ◽  
X Ray ◽  
Cell Parameters ◽  
Diamond Anvil ◽  
Murnaghan Equation ◽  
Volume Decrease

AbstractA single crystal of natrojarosite, NaFe3(SO4)2(OH)6, was investigated by single-crystal X-ray diffraction at high-pressure conditions (up to 8.8 GPa) using a diamond-anvil cell. The unit-cell parameters were determined at 11 different pressures and no indications of a phase transition were found up to the maximum pressure reached. The volume and axial moduli were fitted to a third-order Birch–Murnaghan equation-of-state which gave the following values: V0 = 769.6(2) Å3, KT0 = 50.6(9) GPa, K' = 9.9(4); a = 7.3172(6) Å, KT0 = 104(2), K' = 7.6(9); c = 16.5965(20) Å, KT0 = 24.6(4) and K' = 7.1(2). The crystal structure of natrojarosite was refined at seven different pressures up to 8.779(11) GPa [a = 7.3170(4), c = 16.5955(5) Å and V = 769.46(9) Å3 in Rm at 0.00010(1) GPa and a = 7.1594(8), c = 15.6003(17) Å and V = 692.49(8) Å3 at 8.779(11) GPa]. The structural analysis shows that the 12-fold Na polyhedron accommodates most of the deformation by a large volume decrease (14%) and strong polyhedral distortion (63%). Our results indicate that natrojarosite has the most compressible structure of the supergroup studied so far, and has a very strong axial anisotropy.

scholarly journals High Pressure Behavior of Mascagnite from Single Crystal Synchrotron X-ray Diffraction Data

Crystals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 976
Author(s):  
Paola Comodi ◽  
Maximiliano Fastelli ◽  
Giacomo Criniti ◽  
Konstantin Glazyrin ◽  
Azzurra Zucchini
Keyword(s):  
High Pressure ◽  
Single Crystal ◽  
Room Temperature ◽  
Diamond Anvil Cell ◽  
Geometrical Parameters ◽  
X Ray Diffraction ◽  
Third Order ◽  
X Ray ◽  
Diamond Anvil ◽  
Murnaghan Equation

High-pressure synchrotron X-ray diffraction was carried out on a single crystal of mascagnite, compressed in a diamond anvil cell. The sample maintained its crystal structure up to ~18 GPa. The volume–pressure data were fitted by a third-order Birch–Murnaghan equation of state (BM3-EOS) yielding K0 = 20.4(7) GPa, K’0 = 6.1(2), and V0 = 499(1) Å3, as suggested by the F-f plot. The axial compressibilities, calculated with BM3-EOS, were K0a = 35(3), K’0a = 7.7(7), K0b = 10(3), K’0b = 7(1), K0c = 25(1), and K’0c = 4.3(2) The axial moduli measured using a BM2-EOS and fixing K’0 equal to 4, were K0a = 52(2), K0b = 20 (1), and K0c = 29.6(4) GPa, and the anisotropic ratio of K0a:K0b:K0c = 1:0.4:0.5. The evolution of crystal lattice and geometrical parameters indicated no phase transition until 17.6 GPa. Sulphate polyhedra were incompressible and the density increase of 30% compared to investigated pressure should be attributed to the reduction of weaker hydrogen bonds. In contrast, some of them, directed along [100], were very short at room temperature, below 2 Å, and showed a very low compressibility. This configuration explains the anisotropic compressional behavior and the lowest compressibility of the a axis.

scholarly journals The High Pressure Behavior of Galenobismutite, PbBi2S4: A Synchrotron Single Crystal X-ray Diffraction Study

Crystals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 210 ◽  
Author(s):  
Paola Comodi ◽  
Azzurra Zucchini ◽  
Tonci Balić-Žunić ◽  
Michael Hanfland ◽  
Ines Collings
Keyword(s):  
High Pressure ◽  
Single Crystal ◽  
Structural Changes ◽  
Calcium Ferrite ◽  
X Ray Diffraction ◽  
Third Order ◽  
Electron Pairs ◽  
X Ray ◽  
Cation Sites ◽  
Murnaghan Equation

High-pressure single-crystal synchrotron X-ray diffraction data for galenobismutite, PbBi2S4 collected up to 20.9 GPa, were fitted by a third-order Birch-Murnaghan equation of state, as suggested by a FE-fE plot, yielding V0 = 697.4(8) Å3, K0 = 51(1) GPa and K’ = 5.0(2). The axial moduli were M0a = 115(7) GPa and Ma’ = 28(2) for the a axis, M0b = 162(3) GPa and Mb’ = 8(3) for the b axis, M0c = 142(8) GPa and Mc’ = 26(2) for the c axis, with refined values of a0, b0, c0 equal to 11.791(7) Å, 14.540(6) Å 4.076(3) Å, respectively, and a ratio equal to M0a:M0b:M0c = 1.55:1:1.79. The main structural changes on compression were the M2 and M3 (occupied by Bi, Pb) movements toward the centers of their respective trigonal prism bodies and M3 changes towards CN8. The M1 site, occupied solely by Bi, regularizes the octahedral form with CN6. The eccentricities of all cation sites decreased with compression testifying for a decrease in stereochemical expression of lone electron pairs. Galenobismutite is isostructural with calcium ferrite CaFe2O4, the suggested high pressure structure can host Na and Al in the lower mantle. The study indicates that pressure enables the incorporation of other elements in this structure, increasing its potential significance for mantle mineralogy.

A high-pressure study of Ti3O5 by X-ray diffraction and synchrotron radiation. 1. Pressures up to 38.6 GPa

1989 ◽  
Vol 22 (2) ◽  
pp. 119-122 ◽  
Author(s):  
S. Åsbrink ◽  
L. Gerward ◽  
J. S. Olsen
Keyword(s):  
High Pressure ◽  
Synchrotron Radiation ◽  
Maximum Pressure ◽  
X Ray Diffraction ◽  
Cell Axis ◽  
X Ray ◽  
Powder Samples ◽  
Diamond Anvil ◽  
Murnaghan Equation ◽  
High Pressure Study

High-pressure X-ray diffraction studies have been performed on powder samples of β-Ti3O5 (C2/m) for pressures up to 38.6 GPa using synchrotron radiation and a diamond-anvil cell. The compressibility is highly anisotropic. Thus, the compression Δl/l 0 for the maximum pressure investigated is 5.4, 0.8 and 6.7% for the unit-cell axis directions a, b and c, respectively. The anisotropy is reasonable, considering the crystal structure. The bulk modulus B 0, determined from the Murnaghan equation, is 173(10) GPa and B′0 is 7(1).

scholarly journals Comparison between beryllium and diamond-backing plates in diamond-anvil cells: Application to single-crystal x-ray diffraction high-pressure data

2011 ◽  
Vol 82 (5) ◽  
pp. 055111 ◽  
Author(s):  
Benedetta Periotto ◽  
Fabrizio Nestola ◽  
Tonci Balic-Zunic ◽  
Ross J. Angel ◽  
Ronald Miletich ◽  
...  
Keyword(s):  
High Pressure ◽  
Single Crystal ◽  
Pressure Data ◽  
X Ray Diffraction ◽  
Diamond Anvil Cells ◽  
X Ray ◽  
Diamond Anvil

Microporous crystal structure of labuntsovite-Fe and high-pressure behavior up to 23 GPa

2018 ◽  
Vol 74 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Sergey M. Aksenov ◽  
Elena A. Bykova ◽  
Ramiza K. Rastsvetaeva ◽  
Nikita V. Chukanov ◽  
Irina P. Makarova ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Single Crystal ◽  
Cross Section ◽  
Structure Refinement ◽  
Alkaline Complex ◽  
X Ray ◽  
Cell Parameters ◽  
Diamond Anvil ◽  
The Stability

Labuntsovite-Fe, an Fe-dominant member of the labuntsovite subgroup, was first discovered in the Khibiny alkaline massif on Mt Kukisvumchorr [Khomyakov et al. (2001). Zap. Vseross. Mineral. Oba, 130, 36–45]. However, no data are published about the crystal structure of this mineral. Labuntsovite-Fe from a peralkaline pegmatite located on Mt Nyorkpakhk, in the Khibiny alkaline complex, Kola Peninsula, Russia, has been investigated by means of electron microprobe analyses, single-crystal X-ray structure refinement, and IR and Raman spectroscopies. Monoclinic unit-cell parameters of labuntsovite-Fe are: a = 14.2584 (4), b = 13.7541 (6), c = 7.7770 (2) Å, β = 116.893 (3)°; V = 1360.22 (9) Å3; space group C2/m. The structure was refined to final R 1 = 0.0467, wR 2 = 0.0715 for 3202 reflections [I > 3σ(I)]. The refined crystal chemical formula is (Z = 2): Na2K2Ba0.7[(Fe0.5Ti0.1Mg0.05)(H2O)1.3]{[Ti2(Ti1.9Nb0.1)(O,OH)4][Si4O12]2}·4H2O. The high-pressure in situ single-crystal X-ray diffraction study of the labuntsovite-Fe has been carried out in a diamond anvil cell. The labuntsovite-type structure is stable up to 23 GPa and phase transitions are not observed. Calculations using the BM3 equation of state resulted in the bulk modulus K = 72 (2) GPa, K′0 = 3.7 (2) and V 0 = 1363 (2) Å3. Compressing of the heteropolyhedral zeolite-like framework leads to the deformation of main structural units. Octahedral rods show the gradual increase of distortion and the wave-like character of rods becomes more distinct. Rod deformations result in the distortion of the silicon–oxygen ring which is not equal in different directions. Structural channels are characterized by a different ellipticity–pressure relationship: the cross-section of the largest channel I and channel II demonstrates the stability of the geometrical characteristics which practically do not depend on pressure: ∊channel I ≃ 0.85 (4) (cross-section is rather regular) and ∊channel II ≃ 0.52 (2) within the whole pressure range. However, channel III is characterized by the increasing of ellipticity with pressure (∊ = 0.40 → 0.10).

X-ray Diffraction Study of the Crystal Structure of the Tl Ternary Chalcogenides Tl2x In2(1−x)Se2, x = 0.2, 0.3,...0.9

1998 ◽  
Vol 54 (4) ◽  
pp. 358-364 ◽  
Author(s):  
K. G. Hatzisymeon ◽  
S. C. Kokkou ◽  
A. N. Anagnostopoulos ◽  
P. I. Rentzeperis
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Rietveld Method ◽  
Direct Methods ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Single Crystal Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
Volume Decrease

A series of thallium ternary chalcogenides with the composition Tl2x In2(1−x)Se2, x = 0.2, 0.3,...0.9, have been studied by X-ray powder and, for some of them, single-crystal diffraction. They are tetragonal, space group I4/mcm, Z = 4, and isostructural with the binary semiconductor TlSe. Their crystal structures have been solved by direct methods and refined by the Rietveld method to a precision which is satisfactorily comparable to single-crystal results. As x is changed from x = 0.2 to x = 0.9 the unit-cell parameters and volume decrease or increase following Kurnakov's law, which is valid for solid solutions. Refined positional parameters of Se, In—Se and Tl—Se bond lengths vary with x also according to the same law. The distribution of In and Tl cations in 4(a) and 4(b) sites depends on the stoichiometry x and the crystals are composed of [In3+Se2]_{\infty}^- chains along the c axis in which InSe4 tetrahedra share edges; the chains are interconnected with Tl+(In+) ions.

HIGH-PRESSURE STRUCTURE STUDY OF CuBa2Ca3Cu4O10 + δ SUPERCONDUCTOR

2005 ◽  
Vol 19 (06) ◽  
pp. 313-316
Author(s):  
X. M. QIN ◽  
Y. YU ◽  
G. M. ZHANG ◽  
F. Y. LI ◽  
J. LIU ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Room Temperature ◽  
Diamond Anvil Cell ◽  
Structure Study ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diamond Anvil ◽  
Murnaghan Equation

In-situ high-pressure energy dispersive X-ray diffraction measurements on CuBa 2- Ca 3 Cu 4 O 10 + δ (Cu-1234) have been performed by using diamond anvil cell (DAC) device with synchrotron radiation. The results suggest that the crystal structure of Cu-1234 superconductor is stable under pressures up to 34 GPa at room temperature. According to the Birch–Murnaghan equation of state, the bulk modulus is obtained to be ~ 150 GPa.

High pressure single crystal X-ray diffraction study on α-quartz

1999 ◽  
Vol 214 (6) ◽  
Author(s):  
J. Kim-Zajonz ◽  
S. Werner ◽  
H. Schulz
Keyword(s):  
High Pressure ◽  
Single Crystal ◽  
The Other ◽  
Data Sets ◽  
Theoretical Studies ◽  
Intensity Data ◽  
X Ray Diffraction ◽  
Pressure Derivative ◽  
X Ray ◽  
Murnaghan Equation

AbstractSingle crystal X-ray diffraction experiments onVolumina of the unit cell were determined to 13.1 GPa, by combining the data with data taken from the literature; the bulk modulus and pressure derivative calculate to 38.7(3) GPa and 5.2(1) respectively according to a Birch-Murnaghan equation of state.Intensity data were collected at 10.9(1), 12.0(1), 12.1(1), 12.6(1) and 13.1(1) GPa. From the five intensity data sets, one was collected using synchrotron radiation at HASYLAB/DESY and the other four using a conventional X-ray tube. Results show that the SiOIn addition to the five intensity data sets collected, X-ray diffraction experiments were carried out up to 19.3 GPa in order to address the question of when the structure undergoes amorphization. It was observed that up to 19.3 GPa, no pressure-induced amorphization takes place. This result is in agreement with studies carried out on powder quartz and theoretical studies.

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