scholarly journals High-pressure-induced structural changes, amorphization and molecule penetration in MFI microporous materials: a review

2014 ◽  
Vol 70 (3) ◽  
pp. 444-451 ◽  
Author(s):  
Giovanna Vezzalini ◽  
Rossella Arletti ◽  
Simona Quartieri
Keyword(s):  
High Pressure ◽  
Comparative Study ◽  
Structural Changes ◽  
Microporous Materials ◽  
Deformation Mechanisms ◽  
Silica Phase ◽  
Pressure Behavior ◽  
Framework Composition

This is a comparative study on the high-pressure behavior of microporous materials with an MFI framework type (i.e.natural mutinaite, ZSM-5 and the all-silica phase silicalite-1), based onin-situexperiments in which penetrating and non-penetrating pressure-transmitting media were used. Different pressure-induced phenomena and deformation mechanisms (e.g.pressure-induced over-hydration, pressure-induced amorphization) are discussed. The influence of framework and extra-framework composition and of the presence of silanol defects on the response to the high pressure of MFI-type zeolites is discussed.

Comparative study of the high-pressure behavior of ZnV2O6, Zn2V2O7, and Zn3V2O8

2020 ◽  
Vol 837 ◽  
pp. 155505 ◽  
Author(s):  
D. Díaz-Anichtchenko ◽  
D. Santamaria-Perez ◽  
T. Marqueño ◽  
J. Pellicer-Porres ◽  
J. Ruiz-Fuertes ◽  
...  
Keyword(s):  
High Pressure ◽  
Comparative Study ◽  
Pressure Behavior

Structural properties of ammonium iodide under high pressure

RSC Advances ◽  
2015 ◽  
Vol 5 (50) ◽  
pp. 40336-40340 ◽  
Author(s):  
Yanping Huang ◽  
Xiaoli Huang ◽  
Lu Wang ◽  
Gang Wu ◽  
Defang Duan ◽  
...  
Keyword(s):  
High Pressure ◽  
Raman Scattering ◽  
Structural Properties ◽  
Ammonium Iodide ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pressure Behavior

The high-pressure behavior of ammonium iodide (NH4I) has been investigated by in situ synchrotron X-ray diffraction (XRD) and Raman scattering up to 40 GPa.

scholarly journals High-pressure behavior of Fe2O3

2014 ◽  
Vol 70 (a1) ◽  
pp. C49-C49
Author(s):  
Elena Bykova ◽  
Maxim Bykov ◽  
Vitali Prakapenka ◽  
Zuzana Konôpková ◽  
Hanns-Peter Liermann ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Laser Heating ◽  
Structural Changes ◽  
Structural Information ◽  
Orthorhombic Phase ◽  
Structural Data ◽  
Type Structure ◽  
Pressure Behavior ◽  
High Temperature Xrd

High pressure behavior of Fe2O3has been a long-standing subject of research due to its high importance for understanding Earth's interiors. At pressures from 40 to 60 GPa it undergoes a series of transformations, such as structural changes with a large volume discontinuity (~10 %), a drop of the resistivity, a spin crossover of Fe3+, and a disappearance of the ordered magnetic state. The crystal structure of the phase(s) observed on compression at ambient temperature above 50 GPa is still under question since only powder X-ray diffraction (XRD) data were available so far. Mössbauer and Raman spectroscopy studies cannot provide definitive structural information. Applying laser heating to Fe2O3, compressed up to 70 GPa and above, results in a distinct reconstructive phase transition to the CaIrO3-type structure, according to powder XRD. Poverty of the available structural data encouraged us to perform a series of high-pressure and high-temperature XRD experiments on single crystals of Fe2O3in diamond anvil cells. We have studied the behavior of Fe2O3at pressures up to 100 GPa and temperatures up to 2500 K. Here we report crystal structures of two novel high-pressure Fe2O3polymorphs, as well as the relations between a spin state of iron atoms and the crystal chemistry of the iron compound. In our compression experiments initially hematite-structured Fe2O3transformed to a new phase at ~54 GPa with 10 % of the volume reduction. This phase has a triclinic distorted perovskite-type structure. The second reconstructive transition occurred at 66–70 GPa with 3 % of the volume discontinuity and resulted in formation of an orthorhombic phase. Laser heating to ~21001100 K at pressures above 70 GPa promoted a transition to a Cmcm CaIrO3-type phase, whose crystal structure was refined by means of single crystal XRD to R1~ 9.7 %. Decompression experiments showed that the Cmcm phase transforms back to hematite at pressures between ~25 and 15 GPa.

Comparative Study of the High-Pressure Behavior of As, Sb, and Bi

ChemInform ◽  
2003 ◽  
Vol 34 (16) ◽  
Author(s):  
Ulrich Haeussermann ◽  
Karin Soederberg ◽  
Rolf Norrestam
Keyword(s):  
High Pressure ◽  
Comparative Study ◽  
Pressure Behavior

scholarly journals High-pressure behavior and thermoelastic properties of niobium studied by in situ x-ray diffraction

2014 ◽  
Vol 116 (1) ◽  
pp. 013516 ◽  
Author(s):  
Yongtao Zou ◽  
Xintong Qi ◽  
Xuebing Wang ◽  
Ting Chen ◽  
Xuefei Li ◽  
...  
Keyword(s):  
High Pressure ◽  
X Ray Diffraction ◽  
Thermoelastic Properties ◽  
X Ray ◽  
Pressure Behavior

scholarly journals Development of synchrotron X-ray micro-tomography under extreme conditions of pressure and temperature

2017 ◽  
Vol 24 (1) ◽  
pp. 240-247 ◽  
Author(s):  
M. Álvarez-Murga ◽  
J. P. Perrillat ◽  
Y. Le Godec ◽  
F. Bergame ◽  
J. Philippe ◽  
...  
Keyword(s):  
High Pressure ◽  
Structural Changes ◽  
Three Dimensional ◽  
Crystallographic Structure ◽  
Three Dimensional Imaging ◽  
X Ray ◽  
Wide Range ◽  
Micro Tomography ◽  
Non Destructive

X-ray tomography is a non-destructive three-dimensional imaging/microanalysis technique selective to a wide range of properties such as density, chemical composition, chemical states and crystallographic structure with extremely high sensitivity and spatial resolution. Here the development of in situ high-pressure high-temperature micro-tomography using a rotating module for the Paris–Edinburgh cell combined with synchrotron radiation is described. By rotating the sample chamber by 360°, the limited angular aperture of ordinary high-pressure cells is surmounted. Such a non-destructive high-resolution probe provides three-dimensional insight on the morphological and structural evolution of crystalline as well as amorphous phases during high pressure and temperature treatment. To demonstrate the potentials of this new experimental technique the compression behavior of a basalt glass is investigated by X-ray absorption tomography, and diffraction/scattering tomography imaging of the structural changes during the polymerization of C60 molecules under pressure is performed. Small size and weight of the loading frame and rotating module means that this apparatus is portable, and can be readily installed on most synchrotron facilities to take advantage of the diversity of three-dimensional imaging techniques available at beamlines. This experimental breakthrough should open new ways for in situ imaging of materials under extreme pressure–temperature–stress conditions, impacting diverse areas in physics, chemistry, geology or materials sciences.

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