Formation of a New Phase of C60under the Combined Action of High‐Pressure and X‐Ray Radiation

2008 ◽  
Vol 16 (5-6) ◽  
pp. 486-493
Author(s):  
R. J. Papoular ◽  
R. Le Parc ◽  
C. Levelut ◽  
J. Haines ◽  
V. A. Davydov ◽  
...  
Keyword(s):  
High Pressure ◽  
X Ray ◽  
Combined Action ◽  
New Phase

X-ray evidence for the new phase β-iron at high temperature and high pressure

1996 ◽  
Vol 23 (18) ◽  
pp. 2441-2444 ◽  
Author(s):  
S. K. Saxena ◽  
L. S. Dubrovinsky ◽  
P. Häggkvist
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
X Ray ◽  
New Phase

scholarly journals Crystal structure of the λ-Al13Fe4-type intermetallic (Al,Cu)13(Fe,Cu)4

IUCrData ◽  
2018 ◽  
Vol 3 (3) ◽  
Author(s):  
Cong Liu ◽  
Changzeng Fan
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Structure Analysis ◽  
Structure Type ◽  
X Ray ◽  
X Ray Scattering ◽  
Iron Copper ◽  
Aluminium Copper ◽  
High Pressure Sintering ◽  
New Phase

An (Al,Cu)13(Fe,Cu)4phase of [trideca(aluminium/copper) tetra(iron/copper)] was obtained by the high-pressure sintering (HPS) process of a mixture with composition Al78Cu15Fe7. Structure analysis suggests that Cu atoms can replace both Al and Fe atoms. Such findings support previous anomalous X-ray scattering (AXS) results although deviate from other reports. The new phase adopts the λ-Al13Fe4structure type where Cu atoms partially occupy the 2cand 4isites for Al and Fe atoms, respectively, with occupancies of 0.233 (5) and 0.173 (16).

A new phase of coesite SiO2

1979 ◽  
Vol 149 (3-4) ◽  
Author(s):  
A. Kirfe ◽  
G. Will ◽  
J. Arndt
Keyword(s):  
Aqueous Solution ◽  
High Pressure ◽  
High Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lattice Constants ◽  
Temperature Conditions ◽  
High Pressure High Temperature ◽  
New Phase

AbstractA coesite crystal synthesized from aqueous solution (Arndt and Rombach, 1976) under static high-pressure high-temperature conditions of 44 – 49 kb and 610°C was investigated by X-ray diffraction. From the lattice constants

scholarly journals A new high-pressure polymorph of phosphoric acid

2017 ◽  
Vol 73 (6) ◽  
pp. 1068-1074 ◽  
Author(s):  
Craig L. Bull ◽  
Nicholas P. Funnell ◽  
Colin R. Pulham ◽  
William G. Marshall ◽  
David R. Allan
Keyword(s):  
High Pressure ◽  
Phosphoric Acid ◽  
Orthorhombic Phase ◽  
Void Space ◽  
Structural Behaviour ◽  
Single Crystal Diffraction ◽  
X Ray ◽  
Monoclinic Form ◽  
New Phase ◽  
Molecule Interaction

The high-pressure structural behaviour of phosphoric acid is described. A compression study of the monoclinic phase, using neutron powder diffraction and X-ray single-crystal diffraction, shows that it converts to a previously unobserved orthorhombic phase on decompression. Compression of this new phase is reported up to 6.3 GPa. The orthorhombic phase is found to be more efficiently packed, with reduced void space, resulting in a larger bulk modulus. Molecule–molecule interaction energies reveal a more extensive network of increased attractive forces in the orthorhombic form relative to the monoclinic form, suggesting greater thermodynamic stability.

Nano-probe x-ray analysis and high-resolution imaging on planar defects in high-pressure synthesized infinite-layer superconductor

1994 ◽  
Vol 52 ◽  
pp. 728-729
Author(s):  
Y. Y. Wang ◽  
H. Zhang ◽  
V. P. Dravid ◽  
H. Zhang ◽  
L. D. Marks ◽  
...  
Keyword(s):  
High Pressure ◽  
High Resolution ◽  
Atomic Structure ◽  
Emission Spectra ◽  
High Resolution Electron Microscopy ◽  
Planar Defects ◽  
X Ray ◽  
Infinite Layer ◽  
Resolution Electron ◽  
Resolution Imaging

Azuma et al. observed planar defects in a high pressure synthesized infinitelayer compound (i.e. ACuO2 (A=cation)), which exhibits superconductivity at ~110 K. It was proposed that the defects are cation deficient and that the superconductivity in this material is related to the planar defects. In this report, we present quantitative analysis of the planar defects utilizing nanometer probe xray microanalysis, high resolution electron microscopy, and image simulation to determine the chemical composition and atomic structure of the planar defects. We propose an atomic structure model for the planar defects.Infinite-layer samples with the nominal chemical formula, (Sr1-xCax)yCuO2 (x=0.3; y=0.9,1.0,1.1), were prepared using solid state synthesized low pressure forms of (Sr1-xCax)CuO2 with additions of CuO or (Sr1-xCax)2CuO3, followed by a high pressure treatment.Quantitative x-ray microanalysis, with a 1 nm probe, was performed using a cold field emission gun TEM (Hitachi HF-2000) equipped with an Oxford Pentafet thin-window x-ray detector. The probe was positioned on the planar defects, which has a 0.74 nm width, and x-ray emission spectra from the defects were compared with those obtained from vicinity regions.

Effect of high pressure-temperature on silicon layered structures as determined by X-ray diffraction and electron microscopy

2004 ◽  
Vol 27 (1-3) ◽  
pp. 415-418
Author(s):  
J. Bak-Misiuk ◽  
A. Misiuk ◽  
J. Ratajczak ◽  
A. Shalimov ◽  
I. Antonova ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
High Pressure ◽  
Layered Structures ◽  
X Ray Diffraction ◽  
X Ray

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.

Revisiting the High-Pressure Properties of the Metal-Organic Frameworks ZIF-8 and ZIF-67

2020 ◽  
Author(s):  
Pia Vervoorts ◽  
Stefan Burger ◽  
Karina Hemmer ◽  
Gregor Kieslich
Keyword(s):  
High Pressure ◽  
State Of The Art ◽  
Energy Landscape ◽  
Structural Flexibility ◽  
Zeolitic Imidazolate Frameworks ◽  
Stimuli Responsive ◽  
X Ray Diffraction ◽  
X Ray ◽  
Open Questions ◽  
Metal Organic

The zeolitic imidazolate frameworks ZIF-8 and ZIF-67 harbour a series of fascinating stimuli responsive properties. Looking at their responsitivity to hydrostatic pressure as stimulus, open questions exist regarding the isotropic compression with non-penetrating pressure transmitting media. By applying a state-of-the-art high-pressure powder X-ray diffraction setup, we revisit the high-pressure behaviour of ZIF-8 and ZIF-67 up to <i>p</i> = 0.4 GPa in small pressure increments. We observe a drastic, reversible change of high-pressure powder X-ray diffraction data at <i>p</i> = 0.3 GPa, discovering large volume structural flexibility in ZIF-8 and ZIF-67. Our results imply a shallow underlying energy landscape in ZIF-8 and ZIF-67, an observation that might point at rich polymorphism of ZIF-8 and ZIF-67, similar to ZIF-4(Zn).<br>

Revisiting the High-Pressure Properties of the Metal-Organic Frameworks ZIF-8 and ZIF-67

2020 ◽  
Author(s):  
Pia Vervoorts ◽  
Stefan Burger ◽  
Karina Hemmer ◽  
Gregor Kieslich
Keyword(s):  
High Pressure ◽  
State Of The Art ◽  
Energy Landscape ◽  
Structural Flexibility ◽  
Zeolitic Imidazolate Frameworks ◽  
Stimuli Responsive ◽  
X Ray Diffraction ◽  
X Ray ◽  
Open Questions ◽  
Metal Organic

The zeolitic imidazolate frameworks ZIF-8 and ZIF-67 harbour a series of fascinating stimuli responsive properties. Looking at their responsitivity to hydrostatic pressure as stimulus, open questions exist regarding the isotropic compression with non-penetrating pressure transmitting media. By applying a state-of-the-art high-pressure powder X-ray diffraction setup, we revisit the high-pressure behaviour of ZIF-8 and ZIF-67 up to <i>p</i> = 0.4 GPa in small pressure increments. We observe a drastic, reversible change of high-pressure powder X-ray diffraction data at <i>p</i> = 0.3 GPa, discovering large volume structural flexibility in ZIF-8 and ZIF-67. Our results imply a shallow underlying energy landscape in ZIF-8 and ZIF-67, an observation that might point at rich polymorphism of ZIF-8 and ZIF-67, similar to ZIF-4(Zn).<br>

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