Changes of the crystal structure and the lattice parameter of SrO at high pressure

1973 ◽  
Vol 78 (35) ◽  
pp. 8470-8473 ◽  
Author(s):  
Lin-gun Liu ◽  
William A. Bassett
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Lattice Parameter

Neutron diffraction study of the crystal structure of TlInSe2 at high pressure

2019 ◽  
Vol 33 (15) ◽  
pp. 1950149 ◽  
Author(s):  
N. T. Mamedov ◽  
S. H. Jabarov ◽  
D. P. Kozlenko ◽  
N. A. Ismayilova ◽  
M. Yu. Seyidov ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Neutron Diffraction ◽  
Tetragonal Phase ◽  
Unit Cell Volume ◽  
Diffraction Method ◽  
Lattice Parameter ◽  
Neutron Diffraction Study ◽  
Pressure Derivative ◽  
Neutron Diffraction Method

We have investigated the crystal structure of strongly anisotropic semiconductor TlInSe2 by neutron diffraction method under high pressure upto P = 3.3 GPa. It was shown that the tetragonal phase of TlInSe2 crystal (the space group I4/mcm) is stable in the whole investigated range of pressure. The lattice parameters dependence of the pressure and the unit cell volume are obtained, the linear coefficients of compressibility and the bulk moduli are calculated. At the low pressure, obtained value of compressibility for the lattice parameter a is k[Formula: see text] = 14.23 × 10[Formula: see text] GPa[Formula: see text] and for c is k[Formula: see text] = 5.93 × 10[Formula: see text] GPa[Formula: see text]. Obtained values for bulk modulus B0 and its pressure derivative B[Formula: see text] in tetragonal phase are 30(7) GPa and 4(1), respectively.

High-Pressure Synthesis of Novel Hydride in Ca-TM Systems

2007 ◽  
Vol 26-28 ◽  
pp. 885-888 ◽  
Author(s):  
Y. Yambe ◽  
R. Kataoka ◽  
D. Kyoi ◽  
Atsunori Kamegawa ◽  
Hitoshi Takamura ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Applied Pressure ◽  
Lattice Parameter ◽  
The Novel ◽  
Hydrogen Storage Materials ◽  
High Pressure Synthesis ◽  
Unknown Phase ◽  
Pressure Synthesis ◽  
Fcc Structure

Hydrogen storage materials are attracting much attention as media of storing hydrogen. High-pressure synthesis has been widely used for exploration of novel materials. We have reported that many new Mg-based hydrides or alloys have been synthesized by anvil-type apparatus under the pressure of GPa-order. In Mg - TM ( TM = Nb, Ta ) - H systems, it was reported that novel FCC-type hydride which is similar in crystal structure and composition to Mg7TiH13-16 was synthesized under 8 GPa. On the other hand, there is few reports of novel Ca-based hydrides to be synthesized under high pressure. However, the compressibility of calcium is higher than that of magnesium. Thus, there is a tendency for Ca compounds to be synthesized by lower pressure than Mg ones. This study describes the synthesis of new Ca-based hydrides by this high-pressure techniques. In Ca - TM ( TM = Ti, Hf, V, Nb and Ta ) systems, the influence of applied pressure on present phases were investigated. For the composition of CaH2 - 14.3 mol%ZrH2 in Ca - Zr - H system, novel hydride was synthesized at 1073 K for 2 h under 5 GPa. Crystal structure of the novel hydride was found to be FCC-type with a lattice parameter of a = 0.531 nm. In addition, the thermal stability and hydrogen contents of this novel hydride were investigated. In Ca - Hf - H system, the unknown phase was observed in the sample of CaH2 - 12.5 mol%HfH2 prepared 1073 K for 2 h under 5 GPa. This unknown phase is FCC structure with lattice parameter of a = 0.528(2) nm.

Single Crystal Growth of High-Pressure Phases of Ice and Salt Hydrate Far Below the Original Melting Point by Mixing Alcohol: Crystal Structure Determination of Magnesium Chloride Heptahydrate

2020 ◽  
Author(s):  
Keishiro Yamashita ◽  
Kazuki Komatsu ◽  
Hiroyuki Kagi
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Crystal Growth ◽  
Single Crystal ◽  
Room Temperature ◽  
Growth Technique ◽  
Salt Hydrate ◽  
X Ray

An crystal-growth technique for single crystal x-ray structure analysis of high-pressure forms of hydrogen-bonded crystals is proposed. We used alcohol mixture (methanol: ethanol = 4:1 in volumetric ratio), which is a widely used pressure transmitting medium, inhibiting the nucleation and growth of unwanted crystals. In this paper, two kinds of single crystals which have not been obtained using a conventional experimental technique were obtained using this technique: ice VI at 1.99 GPa and MgCl<sub>2</sub>·7H<sub>2</sub>O at 2.50 GPa at room temperature. Here we first report the crystal structure of MgCl2·7H2O. This technique simultaneously meets the requirement of hydrostaticity for high-pressure experiments and has feasibility for further in-situ measurements.

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.

scholarly journals New high-pressure phases of Fe7N3 and Fe7C3 stable at Earth's core conditions: evidences for carbon–nitrogen isomorphism in Fe-compounds

RSC Advances ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 3577-3581 ◽  
Author(s):  
Nursultan Sagatov ◽  
Pavel N. Gavryushkin ◽  
Talgat M. Inerbaev ◽  
Konstantin D. Litasov
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Ab Initio ◽  
Structure Prediction ◽  
Harmonic Approximation ◽  
Crystal Structure Prediction ◽  
Earth’S Core ◽  
Earth's Core ◽  
Core Conditions

We carried out ab initio calculations on the crystal structure prediction and determination of P–T diagrams within the quasi-harmonic approximation for Fe7N3 and Fe7C3.

scholarly journals Crystal Structure of c‐M5B12O25(OH) (M = Al, Al/Ga, Ga/In) – Three Disordered Cubic Trielborates synthesized under High‐Pressure Conditions

2021 ◽  
Author(s):  
Daniela Vitzthum ◽  
Ingo Widmann ◽  
Daniel S. Wimmer ◽  
Klaus Wurst ◽  
Bastian Joachim-Mrosko ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Pressure

High pressure structural study of MnGeO3 ilmenite

1993 ◽  
Vol 204 (1) ◽  
Author(s):  
N. L. Ross ◽  
B. Reynard ◽  
F. Guyot
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Structural Study

AbstractThe crystal structure of MnGeO

PHASE TRANSITION IN LAYERED PEROVSKITE LIKE MANGANATE Ca3Mn2O7 UNDER HIGH PRESSURE

2001 ◽  
Vol 15 (18) ◽  
pp. 2491-2497 ◽  
Author(s):  
J. L. ZHU ◽  
L. C. CHEN ◽  
R. C. YU ◽  
F. Y. LI ◽  
J. LIU ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Diamond Anvil Cell ◽  
The Other ◽  
Layered Perovskite ◽  
X Ray Diffraction ◽  
Two Phase ◽  
X Ray ◽  
Diamond Anvil

In situ high pressure energy dispersive X-ray diffraction measurements on layered perovskite-like manganate Ca 3 Mn 2 O 7 under pressures up to 35 GPa have been performed by using diamond anvil cell with synchrotron radiation. The results show that the structure of layered perovskite-like manganate Ca 3 Mn 2 O 7 is unstable under pressure due to the easy compression of NaCl-type blocks. The structure of Ca 3 Mn 2 O 7 underwent two phase transitions under pressures in the range of 0~35 GPa. One was at about 1.3 GPa with the crystal structure changing from tetragonal to orthorhombic. The other was at about 9.5 GPa with the crystal structure changing from orthorhombic back to another tetragonal.

High-pressure Syntheses and Characterization of the Rare-earth Fluoride Borates RE2(BO3)F3 (RE=Tb, Dy, Ho)

2013 ◽  
Vol 68 (11) ◽  
pp. 1198-1206 ◽  
Author(s):  
Ernst Hinteregger ◽  
Michael Enders ◽  
Almut Pitscheider ◽  
Klaus Wurst ◽  
Gunter Heymann ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Rare Earth ◽  
Monoclinic Space Group ◽  
Rare Earth Fluoride ◽  
Earth Fluoride ◽  
Structure Determinations ◽  
New Compounds ◽  
Rare Earth Fluorides

The new rare-earth fluoride borates RE2(BO3)F3 (RE=Tb, Dy, Ho) were synthesized under highpressure/ high-temperature conditions of 1:5 GPa=1200 °C for Tb2(BO3)F3 and 3:0 GPa=900 °C for Dy2(BO3)F3 and Ho2(BO3)F3 in a Walker-type multianvil apparatus from the corresponding rareearth sesquioxides, rare-earth fluorides, and boron oxide. The single-crystal structure determinations revealed that the new compounds are isotypic to the known rare-earth fluoride borate Gd2(BO3)F3. The new rare-earth fluoride borates crystallize in the monoclinic space group P21/c (Z = 8) with the lattice parameters a=16:296(3), b=6:197(2), c=8:338(2) Å , b =93:58(3)° for Tb2(BO3)F3, a= 16:225(3), b = 6:160(2), c = 8:307(2) Å , b = 93:64(3)° for Dy2(BO3)F3, and a = 16:189(3), b = 6:124(2), c = 8:282(2) Å , β= 93:69(3)° for Ho2(BO3)F3. The four crystallographically different rare-earth cations (CN=9) are surrounded by oxygen and fluoride anions. All boron atoms form isolated trigonal-planar [BO3]3- groups. The six crystallographically different fluoride anions are in a nearly planar coordination by three rare-earth cations.

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