scholarly journals In‐Situ Synchrotron X‐Ray Diffraction During High Pressure Torsion Deformation of Ni and NiTi

2021 ◽  
Author(s):  
Michael Bernhard Kerber ◽  
Florian Spieckermann ◽  
Roman Schuster ◽  
Cornelia von Baeckmann ◽  
Torben Fischer ◽  
...  
Keyword(s):  
High Pressure ◽  
High Pressure Torsion ◽  
X Ray Diffraction ◽  
X Ray ◽  
Torsion Deformation

scholarly journals Influence of HPT and Accumulative High-Pressure Torsion on the Structure and Hv of a Zirconium Alloy

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 573
Author(s):  
Dmitry Gunderov ◽  
Andrey Stotskiy ◽  
Yuri Lebedev ◽  
Veta Mukaeva
Keyword(s):  
High Pressure ◽  
Zirconium Alloy ◽  
High Pressure Torsion ◽  
Ti Alloy ◽  
Micro Hardness ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ω Phase ◽  
First Time ◽  
Torsion Deformation

The authors previously used the accumulative high-pressure torsion (ACC HPT) method for the first time on steel 316, β-Ti alloy, and bulk metallic glass vit105. On low-alloyed alloys, in particular, the zirconium alloy Zr-1%Nb, the new method was not used. This alloy has a tendency to α → ω phase transformations at using simple HPT. When using ACC HPT, the α → ω transformation can be influenced to a greater extent. This article studies the sliding effect and accumulation of shear strain in Zr-1%Nb alloy at various stages of high-pressure torsion (HPT). The degree of shear deformation at different stages of HPT was estimated. The influence of various high-pressure torsion conditions on the micro-hardness and phase composition by X-ray diffraction (XRD) of Zr-1%Nb was analyzed. It is shown that at high-pressure torsion revolutions of n = 2, anvils and the specimen significantly slip, which is a result of material strengthening. It was found that despite sliding, regular high-pressure torsion resulted in the high strengthening of Zr-1%Nb alloy (micro-hardness more than doubled), and after high-pressure torsion n = 10, up to 97% of the high-pressure ω-phase was formed in it (as in papers of other researchers). Accumulative high-pressure torsion deformation leads to the strongest transformation of the Zr-1%Nb structure and Hv and, therefore, to a higher real strain of the material due to composition by upsetting and torsion in strain cycles.

scholarly journals Pressure-induced Jahn-Teller Switch in the Homoleptic Hybrid Perovskite [(CH3)2NH2]Cu(HCOO)3: Orbital Reordering by Unconventional Degrees of Freedom

2021 ◽  
Author(s):  
Rebecca Scatena ◽  
Michał Andrzejewski ◽  
Roger D Johnson ◽  
Piero Macchi
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Coordination Polymer ◽  
Degrees Of Freedom ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hybrid Perovskite ◽  
Jahn Teller

Through in-situ, high-pressure x-ray diffraction experiments we have shown that the homoleptic perovskite-like coordination polymer [(CH3)2NH2]Cu(HCOO)3 undergoes a pressure-induced orbital reordering phase transition above 5.20 GPa. This transition is distinct...

PHASE TRANSITION IN LAYERED PEROVSKITE LIKE MANGANATE Ca3Mn2O7 UNDER HIGH PRESSURE

2001 ◽  
Vol 15 (18) ◽  
pp. 2491-2497 ◽  
Author(s):  
J. L. ZHU ◽  
L. C. CHEN ◽  
R. C. YU ◽  
F. Y. LI ◽  
J. LIU ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Diamond Anvil Cell ◽  
The Other ◽  
Layered Perovskite ◽  
X Ray Diffraction ◽  
Two Phase ◽  
X Ray ◽  
Diamond Anvil

In situ high pressure energy dispersive X-ray diffraction measurements on layered perovskite-like manganate Ca 3 Mn 2 O 7 under pressures up to 35 GPa have been performed by using diamond anvil cell with synchrotron radiation. The results show that the structure of layered perovskite-like manganate Ca 3 Mn 2 O 7 is unstable under pressure due to the easy compression of NaCl-type blocks. The structure of Ca 3 Mn 2 O 7 underwent two phase transitions under pressures in the range of 0~35 GPa. One was at about 1.3 GPa with the crystal structure changing from tetragonal to orthorhombic. The other was at about 9.5 GPa with the crystal structure changing from orthorhombic back to another tetragonal.

scholarly journals In situ observation of phase changes of a silica-supported cobalt catalyst for the Fischer–Tropsch process by the development of a synchrotron-compatible in situ/operando powder X-ray diffraction cell

2018 ◽  
Vol 25 (6) ◽  
pp. 1673-1682 ◽  
Author(s):  
Adam S. Hoffman ◽  
Joseph A. Singh ◽  
Stacey F. Bent ◽  
Simon R. Bare
Keyword(s):  
High Pressure ◽  
Elevated Pressure ◽  
Phase Changes ◽  
In Situ Observation ◽  
X Ray Diffraction ◽  
Fischer Tropsch ◽  
X Ray ◽  
And Performance ◽  
Co Nanoparticles

In situ characterization of catalysts gives direct insight into the working state of the material. Here, the design and performance characteristics of a universal in situ synchrotron-compatible X-ray diffraction cell capable of operation at high temperature and high pressure, 1373 K, and 35 bar, respectively, are reported. Its performance is demonstrated by characterizing a cobalt-based catalyst used in a prototypical high-pressure catalytic reaction, the Fischer–Tropsch synthesis, using X-ray diffraction. Cobalt nanoparticles supported on silica were studied in situ during Fischer–Tropsch catalysis using syngas, H2 and CO, at 723 K and 20 bar. Post reaction, the Co nanoparticles were carburized at elevated pressure, demonstrating an increased rate of carburization compared with atmospheric studies.

scholarly journals In-situ high-pressure x-ray diffraction study of zinc ferrite nanoparticles

2016 ◽  
Vol 56 ◽  
pp. 68-72 ◽  
Author(s):  
S. Ferrari ◽  
R.S. Kumar ◽  
F. Grinblat ◽  
J.C. Aphesteguy ◽  
F.D. Saccone ◽  
...  
Keyword(s):  
High Pressure ◽  
Diffraction Study ◽  
Zinc Ferrite ◽  
Ferrite Nanoparticles ◽  
X Ray Diffraction ◽  
X Ray

scholarly journals In Situ High-Pressure X-ray Diffraction and Raman Spectroscopy Study of Ti3C2Tx MXene

2018 ◽  
Vol 13 (1) ◽  
Author(s):  
Luxi Zhang ◽  
Weitao Su ◽  
Yanwei Huang ◽  
He Li ◽  
Li Fu ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
High Pressure ◽  
Spectroscopy Study ◽  
X Ray Diffraction ◽  
X Ray

scholarly journals The Viscosity and Atomic Structure of Volatile-Bearing Melilititic Melts at High Pressure and Temperature and the Transport of Deep Carbon

Minerals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 267 ◽  
Author(s):  
Vincenzo Stagno ◽  
Veronica Stopponi ◽  
Yoshio Kono ◽  
Annalisa D’Arco ◽  
Stefano Lupi ◽  
...  
Keyword(s):  
Experimental Data ◽  
High Pressure ◽  
Atomic Structure ◽  
Ex Situ ◽  
X Ray Diffraction ◽  
High Pressure And Temperature ◽  
X Ray ◽  
Falling Sphere ◽  
Basaltic Melts

Understanding the viscosity of mantle-derived magmas is needed to model their migration mechanisms and ascent rate from the source rock to the surface. High pressure–temperature experimental data are now available on the viscosity of synthetic melts, pure carbonatitic to carbonate–silicate compositions, anhydrous basalts, dacites and rhyolites. However, the viscosity of volatile-bearing melilititic melts, among the most plausible carriers of deep carbon, has not been investigated. In this study, we experimentally determined the viscosity of synthetic liquids with ~31 and ~39 wt% SiO2, 1.60 and 1.42 wt% CO2 and 5.7 and 1 wt% H2O, respectively, at pressures from 1 to 4.7 GPa and temperatures between 1265 and 1755 °C, using the falling-sphere technique combined with in situ X-ray radiography. Our results show viscosities between 0.1044 and 2.1221 Pa·s, with a clear dependence on temperature and SiO2 content. The atomic structure of both melt compositions was also determined at high pressure and temperature, using in situ multi-angle energy-dispersive X-ray diffraction supported by ex situ microFTIR and microRaman spectroscopic measurements. Our results yield evidence that the T–T and T–O (T = Si,Al) interatomic distances of ultrabasic melts are higher than those for basaltic melts known from similar recent studies. Based on our experimental data, melilititic melts are expected to migrate at a rate ~from 2 to 57 km·yr−1 in the present-day or the Archaean mantle, respectively.

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