Pressure-Induced Fm-3m R-3 Phase Transition in NaSbF6

1997 ◽  
Vol 53 (1) ◽  
pp. 25-31 ◽  
Author(s):  
H. Sowa
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
High Pressure ◽  
Sphere Packing ◽  
Low Pressure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pressure Phase ◽  
Type Crystal

High-pressure X-ray diffraction measurements on NaSbF6 powder were performed up to 5.63 (7) GPa. At ∼0.1 GPa the cubic low-pressure phase with ordered ReO3-type crystal structure undergoes a phase transition into a rhombohedral LiSbF6-type modification. The high-pressure behaviour of this phase is characterized by rotations and distortions of the coordination octahedra, but it also can be described with a sphere-packing deformation. The octahedral distortions are probably caused by cation–cation repulsions.

X-ray diffraction investigations of CaF2 at high pressure

1992 ◽  
Vol 25 (5) ◽  
pp. 578-581 ◽  
Author(s):  
L. Gerward ◽  
J. S. Olsen ◽  
S. Steenstrup ◽  
M. Malinowski ◽  
S. Åsbrink ◽  
...  
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Synchrotron Radiation ◽  
High Pressures ◽  
Low Pressure ◽  
Single Crystal Sample ◽  
X Ray Diffraction ◽  
Crystal Sample ◽  
X Ray ◽  
Pressure Phase

Synchrotron-radiation X-ray diffraction studies of CaF2 at high pressures have been performed on a powder sample up to 45 GPa and on a single-crystal sample up to 9.4 GPa. The bulk modulus of the low-pressure phase was determined to be B 0 = 87 (5) GPa. A phase transition was observed at about 9.5 GPa. The transition is accompanied by a volume contraction of 11%. The high-pressure phase is orthorhombic PbCl2 type (space group Pbnm). The sample only partially reverts to the low-pressure phase upon release of pressure.

A new high-pressure phase transition in clinoferrosilite: In situ single-crystal X-ray diffraction study

2017 ◽  
Vol 102 (3) ◽  
pp. 666-673 ◽  
Author(s):  
Anna Pakhomova ◽  
Leyla Ismailova ◽  
Elena Bykova ◽  
Maxim Bykov ◽  
Tiziana Boffa Ballaran ◽  
...  
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Single Crystal ◽  
Diffraction Study ◽  
High Pressure Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Pressure Phase Transition ◽  
Pressure Phase

scholarly journals Crystal structure of the high-P polymorph of Ca2B6O6(OH)10·2(H2O) (meyerhofferite)

2021 ◽  
Vol 77 (6) ◽  
Author(s):  
Davide Comboni ◽  
Tomasz Poreba ◽  
Francesco Pagliaro ◽  
Tommaso Battiston ◽  
Paolo Lotti ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
High Pressure ◽  
Large Volume ◽  
Atomic Scale ◽  
Deformation Mechanisms ◽  
X Ray Diffraction ◽  
X Ray ◽  
First Order ◽  
Structural Differences

The crystal structure of the high-pressure polymorph of meyerhofferite, ideally Ca2B6O6(OH)10·2(H2O), has been determined by means of single-crystal synchrotron X-ray diffraction data. Meyerhofferite undergoes a first-order isosymmetric phase transition to meyerhofferite-II, bracketed between 3.15 and 3.75 GPa, with a large volume discontinuity. The phase transition is marked by an increase in the coordination number of the boron B1 site, from III to IV, leading to a more interconnected and less compressible structure. The main structural differences between the two polymorphs and the P-induced deformation mechanisms at the atomic scale are discussed.

Crystal structure and the equation of state of thorium monophosphide for pressures up to 50 GPa

1989 ◽  
Vol 22 (1) ◽  
pp. 61-63 ◽  
Author(s):  
J. S. Olsen ◽  
L. Gerward ◽  
U. Benedict ◽  
H. Luo ◽  
O. Vogt
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
High Pressure ◽  
Synchrotron Radiation ◽  
Diamond Anvil Cell ◽  
X Ray Diffraction ◽  
Pressure Derivative ◽  
X Ray ◽  
Cscl Structure ◽  
Diamond Anvil

High-pressure X-ray diffraction studies have been performed on ThP using synchrotron radiation and a diamond-anvil cell. The bulk modulus B 0 and its pressure derivative B′0 have been determined (B 0 = 137 GPa; B′0 = 5.1). A phase transition from the NaCl structure to the CsCl structure was observed at about 30 GPa.

High pressure phase transition in metallic LaB6: Raman and X-ray diffraction studies

2004 ◽  
Vol 129 (12) ◽  
pp. 791-796 ◽  
Author(s):  
Pallavi Teredesai ◽  
D.V.S. Muthu ◽  
N. Chandrabhas ◽  
S. Meenakshi ◽  
V. Vijayakumar ◽  
...  
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
High Pressure Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Pressure Phase Transition ◽  
Pressure Phase

High-pressure Synthesis, Crystal Structure, and Properties of the First Ternary Zirconium Borate β-ZrB2O5

2008 ◽  
Vol 63 (6) ◽  
pp. 707-712 ◽  
Author(s):  
Johanna S. Knyrim ◽  
Hubert Huppertz
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Room Temperature ◽  
High Pressure Phase ◽  
Structure And Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Pressure High Temperature ◽  
Pressure Synthesis ◽  
Pressure Phase

The high-pressure phase β -ZrB2O5 represents the first ternary borate in the system Zr-B-O. The compound was synthesized under high-pressure / high-temperature conditions of 7.5 GPa and 1100 °C in a Walker-type multianvil apparatus. The crystal structure was determined on the basis of single crystal X-ray diffraction data, collected at room temperature. The monoclinic zirconium borate crystallizes in the space group P21/c with the lattice parameters a = 439.04(9), b = 691.2(2), c = 896.8(2) pm, and β = 90.96(3)°. The structure is isotypic to the high-pressure phase β -HfB2O5, which is built up from layers of exclusively corner-sharing BO4 tetrahedra. Between these layers, the cations are coordinated square-antiprismatically by eight oxygen atoms.

High-Pressure Synthesis, Crystal Structure, And Properties Of δ-Ce(Bo2)3

2007 ◽  
Vol 62 (6) ◽  
pp. 759-764 ◽  
Author(s):  
Almut Haberer ◽  
Gunter Heymann ◽  
Hubert Huppertz
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
High Temperature ◽  
Diffraction Data ◽  
Structure And Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Pressure High Temperature ◽  
Pressure Synthesis ◽  
Pressure Phase

The cerium meta-oxoborate δ -Ce(BO2)3 was synthesized under high-pressure / high-temperature conditions of 3.5 GPa and 1050 °C in a Walker-type multianvil apparatus. The crystal structure was determined by single crystal X-ray diffraction data, collected at r. t. The compound crystallizes monoclinicly in the space group P21/c with the lattice parameters a = 422.52(8), b = 1169.7(2), c = 725.2(2) pm, and β = 91.33(3)°. The structure is isotypic to the recently published high-pressure phase δ -La(BO2)3, consisting exclusively of corner sharing [BO4]5− tetrahedra

scholarly journals Crystal Growth and Investigation of High-Pressure Physical Properties of Fe2As

Crystals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 790
Author(s):  
Guangyang Dai ◽  
Changling Zhang ◽  
Sijia Zhang ◽  
Xin He ◽  
Chongwen Ren ◽  
...  
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Physical Properties ◽  
Pressure Range ◽  
High Pressure Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lattice Constants ◽  
High Pressure Phase Transition ◽  
Pressure Phase

We reported the growth of Fe2As single crystals and the study of its physical properties via comprehensive measurements, such as transport properties under pressure and high-pressure synchrotron radiation X-ray diffraction. Fe2As is an antiferromagnetic metal with TN ~ 355 K. Within the pressure range of 100 GPa, no superconductivity was observed above 2 K. The abrupt drop in resistance from 21 to 31.7 GPa suggests a high-pressure phase transition happens. The high-pressure X-ray experiments indicate a new high-pressure phase appears, starting from 27.13 GPa. After the refinement of the high-pressure X-ray data, the pressure dependence of lattice constants of Fe2As (P4/nmm phase) was plotted and the bulk modulus B0 was obtained to be 168.6 GPa.

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