Structural aspects of dense solid halogens under high pressure studied by x-ray diffraction—Molecular dissociation and metallization

1995 ◽  
Vol 56 (10) ◽  
pp. 1439-1444 ◽  
Author(s):  
Hiroshi Fujihisa ◽  
Yasuhiko Fujii ◽  
Kenichi Takemura ◽  
Osamu Shimomura
Author(s):  
Kenichi Takemura ◽  
Kyoko Sato ◽  
Hiroshi Fujihisa ◽  
Mitsuko Onoda

AbstractHigh-pressure powder X-ray diffraction experiments have been carried out on solid iodine at room temperature. A new intermediate phase V has been identified in the pressure range 24–28 GPa, in the close vicinity of the pressure-induced molecular dissociation. The structure is incommensurately modulated, a rare case for elemental solids. The nearest interatomic distances are distributed over a range 2.8–3.2 Å, which characterizes phase V as a transient state between the molecular and monatomic states. We discuss the overall change of the crystal structure of iodine with pressure, which gives an insight into the process of molecular formation and dissociation.


1991 ◽  
Vol 231 ◽  
Author(s):  
Y. Fujii ◽  
Y. Ohishi ◽  
H. Konishi ◽  
N. Nakayama ◽  
T. Shinjo

AbstractThis paper has made an overview on elastic and structural aspects of three distinct superlattices under hydrostatic pressure up to about 8GPa, which were studied by our unique x-ray diffraction technique incorporated with a diamond-anvil cell. They are metallic fcc/fcc Au/Ni, bcc/fcc Mo/Ni, and semiconductive epitaxially-grown PbSe/SnSe superlattices. In their layer-stacking direction, both metallic superlattices show the supermodulus behavior while the semiconductive one doesn't. However, its pressure-driven cubic-to-orthorhombic phase transition, successively taking place in the SnSe and PbSe layers, has been found to significantly shift by stress due to its epitaxial growth.


1980 ◽  
Vol 45 (23) ◽  
pp. 1881-1884 ◽  
Author(s):  
K. Takemura ◽  
S. Minomura ◽  
O. Shimomura ◽  
Y. Fujii

2004 ◽  
Vol 27 (1-3) ◽  
pp. 415-418
Author(s):  
J. Bak-Misiuk ◽  
A. Misiuk ◽  
J. Ratajczak ◽  
A. Shalimov ◽  
I. Antonova ◽  
...  

2020 ◽  
Author(s):  
Pia Vervoorts ◽  
Stefan Burger ◽  
Karina Hemmer ◽  
Gregor Kieslich

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>


2020 ◽  
Author(s):  
Pia Vervoorts ◽  
Stefan Burger ◽  
Karina Hemmer ◽  
Gregor Kieslich

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>


2019 ◽  
Vol 74 (4) ◽  
pp. 357-363
Author(s):  
Daniela Vitzthum ◽  
Hubert Huppertz

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.


Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 724
Author(s):  
Sara Massardo ◽  
Alessandro Cingolani ◽  
Cristina Artini

Rare earth-doped ceria thin films are currently thoroughly studied to be used in miniaturized solid oxide cells, memristive devices and gas sensors. The employment in such different application fields derives from the most remarkable property of this material, namely ionic conductivity, occurring through the mobility of oxygen ions above a certain threshold temperature. This feature is in turn limited by the association of defects, which hinders the movement of ions through the lattice. In addition to these issues, ionic conductivity in thin films is dominated by the presence of the film/substrate interface, where a strain can arise as a consequence of lattice mismatch. A tensile strain, in particular, when not released through the occurrence of dislocations, enhances ionic conduction through the reduction of activation energy. Within this complex framework, high pressure X-ray diffraction investigations performed on the bulk material are of great help in estimating the bulk modulus of the material, and hence its compressibility, namely its tolerance toward the application of a compressive/tensile stress. In this review, an overview is given about the correlation between structure and transport properties in rare earth-doped ceria films, and the role of high pressure X-ray diffraction studies in the selection of the most proper compositions for the design of thin films.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Michael Zoller ◽  
Hubert Huppertz

AbstractThe rare earth oxoborates REB5O8(OH)2 (RE = Ho, Er, Tm) were synthesized in a Walker-type multianvil apparatus at a pressure of 2.5 GPa and a temperature of 673 K. Single-crystal X-ray diffraction data provided the basis for the structure solution and refinement. The compounds crystallize in the monoclinic space group C2 (no. 5) and are composed of a layer-like structure containing dreier and sechser rings of corner sharing [BO4]5− tetrahedra. The rare earth metal cations are coordinated between two adjacent sechser rings. Further characterization was performed utilizing IR spectroscopy.


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