scholarly journals Compressional Behavior of Hydrous Orthoenstatite: Insight into the Nature of LVZ under Continental Plate

Minerals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 71
Author(s):  
Florian Tian-Siang Hua ◽  
Przemyslaw Dera ◽  
Jennifer Kung
Keyword(s):  
Crystal Structure ◽  
Upper Mantle ◽  
Ambient Conditions ◽  
X Ray Diffraction ◽  
Low Velocity ◽  
X Ray ◽  
Low Level ◽  
Al Content ◽  
Continental Plate ◽  
Influence Of Water

A suite of hydrous orthoenstatite crystals were synthesized at 5–7 GPa and 1100–1300 °C, corresponding to the mid upper mantle conditions in continental regions. The synthetic crystals presented a clear, inclusion-free, and euhedral form with a size range from 100 to a few hundred microns. The Al- and water content of crystals were less than 2 wt. % and ranging from ~500 ppm to 1000 ppm, respectively, characterized by Raman and IR spectroscopy, electron microscopy, and SIMS. The analysis shows that the capability of water incorporation for this suite of hydrous orthoenstatite is correlated to the Al-content in the crystal structure. To understand how the detailed crystal structure reflects the influence of water and Al, single crystal X ray diffraction analysis was performed for this suite of hydrous orthoenstatite. By comparing the results obtained at ambient conditions, we find that for low-level of Al-content, <2 wt. %, the Al3+ cation tends to occupy one of tetrahedral sites (TB) only. Analysis of the X ray diffraction results under high pressure indicates that the elasticity of orthoenstatites is insensitive to the presence of low-level water and Al. We use this finding to evaluate the velocity profile at the mid upper mantle of continental regions to compare with seismic observation. The comparison indicates that the cause of the low velocity zone in continental regions originates from the geotherm profile rather than the effect of water on the elasticity of mantle phases.

scholarly journals Discovery of Fe7O9: a new iron oxide with a complex monoclinic structure

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Ryosuke Sinmyo ◽  
Elena Bykova ◽  
Sergey V. Ovsyannikov ◽  
Catherine McCammon ◽  
Ilya Kupenko ◽  
...  
Keyword(s):  
Applied Sciences ◽  
Crystal Structure ◽  
Iron Oxide ◽  
Iron Oxides ◽  
Industrial Applications ◽  
Ambient Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Pressure High Temperature ◽  
Insight Into

Abstract Iron oxides are fundamentally important compounds for basic and applied sciences as well as in numerous industrial applications. In this work we report the synthesis and investigation of a new binary iron oxide with the hitherto unknown stoichiometry of Fe7O9. This new oxide was synthesized at high-pressure high-temperature (HP-HT) conditions, and its black single crystals were successfully recovered at ambient conditions. By means of single crystal X-ray diffraction we determined that Fe7O9 adopts a monoclinic C2/m lattice with the most distorted crystal structure among the binary iron oxides known to date. The synthesis of Fe7O9 opens a new portal to exotic iron-rich (M,Fe)7O9 oxides with unusual stoichiometry and distorted crystal structures. Moreover, the crystal structure and phase relations of such new iron oxide groups may provide new insight into the cycling of volatiles in the Earth’s interior.

Consolidation of Mg2Si Powder Using Shockwave Generated by Projectile Impact

2013 ◽  
Vol 767 ◽  
pp. 177-182 ◽  
Author(s):  
Hiroaki Kishimura ◽  
Yuki Yano ◽  
Hitoshi Matsumoto
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
Milled Powder ◽  
Shock Pressure ◽  
Original Structure ◽  
Ambient Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Shock Compaction ◽  
Phase Transition Pressure

A series of shock compaction experiments on as-received and ball-milled Mg2Si powder were conducted. The crystalline size in the shocked compacts obtained from the ball-milled powder was equivalent to that of the compacts obtained from the as-received powder. Although the shock pressure was higher than the phase transition pressure, the crystal structure reverted to its original structure under ambient conditions. For the shocked compact obtained from the ball-milled powder, a MgO peak appeared in the X-ray diffraction pattern.

scholarly journals CH3NH3PbI3: precise structural consequences of water absorption at ambient conditions

2016 ◽  
Vol 72 (5) ◽  
pp. 716-722 ◽  
Author(s):  
Alla Arakcheeva ◽  
Dmitry Chernyshov ◽  
Massimo Spina ◽  
László Forró ◽  
Endre Horváth
Keyword(s):  
Crystal Structure ◽  
Direct Consequence ◽  
Ambient Conditions ◽  
X Ray Diffraction ◽  
Lead Iodide ◽  
X Ray ◽  
Space Groups ◽  
Tetragonal Unit Cell ◽  
Synchrotron Light ◽  
The Difference

The crystal structure of the pristine (I) and aged (II) crystals of CH3NH3PbI3(hereafter MAPbI3) hybrid organic–inorganic lead iodide has been studied at 293 K with high-precision single-crystal X-ray diffraction using a synchrotron light source. We show that (I) and (II) are characterized by an identical tetragonal unit cell but different space groups:I422 for (I) andP42212 for (II). Both space groups are subgroups ofI4/mcm, which is widely used for MAPbI3. The main difference between (I) and (II) comes from the difference in hydrogen bonds between the MA+cation and the PbI3framework which is the direct consequence of H2O insertion in the aged crystal (II).

Structural and Band-Edge Properties of Cu(AlxIn1-X)S2 (0≤x≤1) Series Chalcopyrite Semiconductors

2012 ◽  
Vol 194 ◽  
pp. 133-138 ◽  
Author(s):  
Ching Hwa Ho ◽  
Chia Chi Pan ◽  
Jian Rong Cai ◽  
Guan Tzu Huang ◽  
Dumitru O. Dumcenco ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Photoelectron Spectroscopy ◽  
Measurement Techniques ◽  
X Ray Diffraction ◽  
Valence Band Structure ◽  
X Ray ◽  
Al Content ◽  
Chalcopyrite Semiconductors ◽  
Structural And Electronic Properties ◽  
Enhanced Strain

We have demonstrated structural and electronic properties of a series solar energy crystals Cu(AlxIn1-x)S2 (0<=x<=1) by using measurement techniques of X-ray diffraction, polarized thermoreflectance (PTR), and X-ray photoelectron spectroscopy (XPS). Single crystals of Cu(AlxIn1-x)S2 (0<=x<=1) (0 and E ^ polarizations. The PTR spectra clearly showed that the energy value of D increases with the increase of Al content x in the Cu(AlxIn1-x)S2 (0<=x<=1) series due to the enhanced strain in the lattice. The composition-dependent crystal-field-splitting energies can be evaluated and determined to be D(x)= (10±2)+( 139±5)×x meV. Based on the experimental analyses, the crystal structure and valence-band structure of the Cu(AlxIn1-x)S2 (0<=x<=1) (0<=x<=1) series are thus realized.

Effect of hydrostatic pressures on the crystal structure of InS

1995 ◽  
Vol 210 (7) ◽  
Author(s):  
U. Schwarz ◽  
H. Hillebrecht ◽  
K. Syassen
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Diffraction Data ◽  
Ambient Pressure ◽  
Lattice Parameters ◽  
Ambient Conditions ◽  
X Ray Diffraction ◽  
X Ray

AbstractWe have measured single crystal X-ray diffraction data of InS at ambient pressure and under hydrostatic pressures up to 4.3 GPa. The redetermination of the crystal structure at ambient conditions shows no major deviations from previous results. Determination of lattice parameters at various pressures confirms an extraordinary large compressibility for the

Crystal Structure Refinements of Ge(tP12), Physical Properties and Pressure-induced Phase Transformation Ge(tP12) ↔ Ge(tI4)

2008 ◽  
Vol 63 (6) ◽  
pp. 608-614 ◽  
Author(s):  
Aron Wosylus ◽  
Yurii Prots ◽  
Walter Schnelle ◽  
Michael Hanfland ◽  
Ulrich Schwarz
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Theoretical Calculations ◽  
Structural Similarity ◽  
Phase Region ◽  
Maximum Pressure ◽  
Ambient Conditions ◽  
X Ray Diffraction ◽  
Two Phase ◽  
X Ray

Single crystals of the modification Ge(tP12) are prepared by compressing semiconductor-grade germanium to pressures above 11(1) GPa and heating to temperatures between 1200(100) and 1500(150) K before a stepwise cooling precedes a complete pressure release. The tetragonal crystal structure of Ge(tP12) is refined by means of single crystal X-ray diffraction data collected at ambient conditions (a = 592.81(2), c = 698.03(3) pm, space group P43212). The atomic arrangement comprising interconnected spiral chains of fourfold symmetry bears a structural similarity to the high-pressure modification S(t I16). High-pressure ambient-temperature powder X-ray diffraction measurements reveal a significant anisotropy of the compressibility compatible with the selected crystal structure description. The determined bulk modulus of Ge(tP12) amounts to 70(1) GPa which is in good agreement with theoretical calculations and similar to experimental values of other four-coordinated germanium allotropes. Ge(tP12) is a diamagnetic semiconductor with χ0 = −3.1(3) ·10−7 emu g−1 and ρ300 K ≈ 6 Ωm at 300 K. At 10.1(3) GPa, the beginning of the formation of Ge(t I 4) indicates the onset of a structural transition. The two-phase region extends up to a maximum pressure of 13.0(5) GPa in the direction of increasing pressures. Upon stepwise decompression, the phase Ge(t P12) is reformed from Ge(t I4) at 9(1) GPa.

Crystal structure of an inclusion complex between chiral monoaza-15-crown-5 and S(–)-1-phenyl-ethyl ammonium percholorate

2003 ◽  
Vol 218 (5) ◽  
Author(s):  
Süheyla Özbey ◽  
F. B. Kaynak ◽  
M. Toğrul ◽  
N. Demirel ◽  
H. Hoşgören
Keyword(s):  
Crystal Structure ◽  
Inclusion Complex ◽  
Single Crystal ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
New Type

AbstractA new type of inclusion complex, S(–)-1 phenyl ethyl ammonium percholorate complex of R-(–)-2-ethyl - N - benzyl - 4, 7, 10, 13 - tetraoxa -1- azacyclopentadecane, has been prepared and studied by NMR, IR and single crystal X-ray diffraction techniques. The compound crystallizes in space group

Crystal Forms of Semisynthetic Ergot Alkaloid Terguride

2002 ◽  
Vol 67 (4) ◽  
pp. 479-489 ◽  
Author(s):  
Michal Hušák ◽  
Bohumil Kratochvíl ◽  
Ivana Císařová ◽  
Ladislav Cvak ◽  
Alexandr Jegorov ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Ergot Alkaloid ◽  
Simplified Model ◽  
Quantum Mechanical ◽  
Quantum Mechanical Calculations ◽  
X Ray Diffraction ◽  
Torsion Angles ◽  
Crystal Forms ◽  
X Ray ◽  
Independent Molecules

Two new structures of semisynthetic ergot alkaloid terguride created by unusual number of symmetry-independent molecules were determined by X-ray diffraction methods at 150 K. Form A (monoclinic, P212121, Z = 12) contains three symmetry-independent terguride molecules and two molecules of water in the asymmetric part of the unit cell. The form CA (monoclinic, P21, Z = 8) is an anhydrate remarkable by the presence of four symmetry-independent molecules in the crystal structure. Conformations of twelve symmetry-independent molecules that were found in four already described terguride structures are compared with torsion angles obtained by ab initio quantum-mechanical calculations for the simplified model of N-cyclohexyl-N'-diethylurea.

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.

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