X-ray Study with Synchrotron Radiation for New Filled Skutterudite GdFe4As12 at Ambient Pressure and High Pressures

ABSTRACTThe equation of state (EOS) of Li3N has been determined by energy-dispersive x-ray diffraction (EDXD) using synchrotron radiation up to 35 GPa at ambient temperature. Both the hexagonal D6h4(P63/mmc) and the hexagonal D6h1(P6/mmm) phases were present at ambient pressure. The D6h1 -structure completely transforms into the D6h4 -structure at modest pressure. The change in Gibb's free energy as a function of pressure for Li3N was calculated using the experimental EOS.

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High-pressure transformations of NbO2F

Acta Crystallographica Section B Structural Science ◽

10.1107/s0108768199015311 ◽

2000 ◽

Vol 56 (2) ◽

pp. 189-196 ◽

Cited By ~ 15

Author(s):

Stefan Carlson ◽

Ann-Kristin Larsson ◽

Franziska E. Rohrer

Keyword(s):

Phase Transition ◽

High Pressure ◽

High Pressures ◽

Ambient Pressure ◽

Close Packing ◽

Hexagonal Close Packing ◽

Rietveld Refinements ◽

X Ray ◽

Anion Coordination ◽

Diamond Anvil

The ReO3-type structure NbO2F, niobium dioxyfluoride, has been studied at high pressures using diamond anvil cells and synchrotron X-ray radiation. High-pressure powder diffraction measurements have been performed up to 40.1 GPa. A phase transition from the cubic (Pm3¯m) ambient pressure structure to a rhombohedral (R3¯c) structure at 0.47 GPa has been observed. Rietveld refinements at 1.38, 1.96, 3.20, 6.23, 9.00 and 10.5 GPa showed that the transition involves an a − a − a − tilting of the cation–anion coordination octahedra and a change of the anion–anion arrangement to approach hexagonal close packing. Compression and distortion of the Nb(O/F)6 octahedra is also revealed by the Rietveld refinements. At 17–18 GPa, the diffraction pattern disappears and the structure becomes X-ray amorphous.

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Small-angle x-ray scattering and density measurements of liquid Se50−Te50mixture at high temperatures and high pressures using synchrotron radiation

Journal of Physics Conference Series ◽

10.1088/1742-6596/215/1/012078 ◽

2010 ◽

Vol 215 ◽

pp. 012078 ◽

Cited By ~ 1

Author(s):

Y Kajihara ◽

M Inui ◽

K Matsuda ◽

Y Tomioka

Keyword(s):

Synchrotron Radiation ◽

High Temperatures ◽

Small Angle ◽

High Pressures ◽

Density Measurements ◽

X Ray ◽

X Ray Scattering ◽

Ray Scattering

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The solvothermal synthesis of γ-AlOOH nanoflakes and their compression behaviors under high pressures

RSC Advances ◽

10.1039/c6ra27571k ◽

2017 ◽

Vol 7 (9) ◽

pp. 4904-4911 ◽

Cited By ~ 11

Author(s):

Xudong Zhou ◽

Jian Zhang ◽

Yanmei Ma ◽

Hui Tian ◽

Yue Wang ◽

...

Keyword(s):

High Pressure ◽

Synchrotron Radiation ◽

Solvothermal Synthesis ◽

High Pressures ◽

X Ray Diffraction ◽

X Ray ◽

Radiation Angle

The compression behaviors of γ-AlOOH nanoflakes were investigated via in situ high pressure synchrotron radiation angle dispersive X-ray diffraction techniques.

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X-ray diffraction investigations of CaF2 at high pressure

Journal of Applied Crystallography ◽

10.1107/s0021889892004096 ◽

1992 ◽

Vol 25 (5) ◽

pp. 578-581 ◽

Cited By ~ 79

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.

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