scholarly journals Superconductivity above 200K Observed in Superhydrides of Calcium

2021 ◽  
Author(s):  
Zhiwen Li ◽  
Xin He ◽  
Changling Zhang ◽  
Sijia Zhang ◽  
Yating Jia ◽  
...  
Keyword(s):  
Room Temperature ◽  
Diamond Anvil Cell ◽  
Upper Critical Field ◽  
X Ray ◽  
Experimental Discovery ◽  
Potential Applications ◽  
Diamond Anvil ◽  
Pressure Resistance ◽  
Critical Temperature Tc

Abstract Searching for superconductivity with Tc near room temperature is of great interest both for fundamental science & potential applications. Here we report the experimental discovery of superconductivity with maximum critical temperature(Tc) above 210 K in calcium superhydrides, the third type hydride experimentally showing superconductivity above 200K in addition to sulfur hydride & rare earth hydride system. The materials are synthesized at the synergetic conditions of 160~190 GPa and ~2000K using diamond anvil cell combined with in-situ laser heating technique. The superconductivity was studied through in situ high pressure resistance measurements in applied magnetic field for the sample quenched from high temperature while maintained at the synthesized pressure. The upper critical field was estimated to be ~268T while the GL coherent length is ~11 Å. The in situ x ray diffractions with synchrotron suggest that the synthesized calcium hydrides are primarily composed of CaH6 while there also exist other calcium hydrids with different hydrogen.

HIGH-PRESSURE STRUCTURE STUDY OF CuBa2Ca3Cu4O10 + δ SUPERCONDUCTOR

2005 ◽  
Vol 19 (06) ◽  
pp. 313-316
Author(s):  
X. M. QIN ◽  
Y. YU ◽  
G. M. ZHANG ◽  
F. Y. LI ◽  
J. LIU ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Room Temperature ◽  
Diamond Anvil Cell ◽  
Structure Study ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diamond Anvil ◽  
Murnaghan Equation

In-situ high-pressure energy dispersive X-ray diffraction measurements on CuBa 2- Ca 3 Cu 4 O 10 + δ (Cu-1234) have been performed by using diamond anvil cell (DAC) device with synchrotron radiation. The results suggest that the crystal structure of Cu-1234 superconductor is stable under pressures up to 34 GPa at room temperature. According to the Birch–Murnaghan equation of state, the bulk modulus is obtained to be ~ 150 GPa.

Reversible phase transitions in Na2S under pressure: a comparison with the cation array in Na2SO4

2001 ◽  
Vol 57 (2) ◽  
pp. 151-156 ◽  
Author(s):  
A. Vegas ◽  
A. Grzechnik ◽  
K. Syassen ◽  
I. Loa ◽  
M. Hanfland ◽  
...  
Keyword(s):  
Room Temperature ◽  
Diamond Anvil Cell ◽  
Lattice Parameters ◽  
X Ray Diffraction ◽  
Rietveld Refinements ◽  
X Ray ◽  
Diamond Anvil ◽  
Binary Compounds ◽  
Reversible Phase

The structural behavior of the antifluorite Na2S, disodium sulfide, has been studied under pressure up to 22 GPa by in situ synchrotron X-ray diffraction experiments in a diamond anvil cell at room temperature. At approximately 7 GPa, Na2S undergoes a first phase transition to the orthorhombic anticotunnite (PbCl2) structure (Pnma, Z = 4). The lattice parameters at 8.2 GPa are a = 6.707 (5), b = 4.120 (3), c = 8.025 (4) Å. At approximately 16 GPa, Na2S undergoes a second transition adopting the structure of the Ni2In-type (P63/mmc, Z = 2). The lattice parameters at 16.6 GPa are a = 4.376 (18), c = 5.856 (9) Å. Both pressure-induced phases have been confirmed by full Rietveld refinements. An inspection of the cation array of Na2SO4 reveals that its Na2S subarray is also of the Ni2In-type. This feature represents a new example of how the cation arrangements in ternary oxides correspond to the topology of the respective binary compounds. We discuss analogies between the insertion of oxygen and the application of pressure.

Halogen...halogen interactions in pressure-frozen ortho- and meta-dichlorobenzene isomers

2007 ◽  
Vol 63 (1) ◽  
pp. 124-131 ◽  
Author(s):  
Maciej Bujak ◽  
Kamil Dziubek ◽  
Andrzej Katrusiak
Keyword(s):  
Intermolecular Interactions ◽  
Room Temperature ◽  
Diamond Anvil Cell ◽  
Crystal Packing ◽  
Molecular Shape ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diamond Anvil ◽  
Steric Hindrances

Isomers 1,2-dichlorobenzene (o-DCB) and 1,3-dichlorobenzene (m-DCB) were high-pressure frozen in-situ in a Merrill–Bassett diamond–anvil cell and their structures determined at room temperature and at 0.18 (5) GPa for o-DCB, and 0.17 (5) GPa for m-DCB by single-crystal X-ray diffraction. The patterns of halogen...halogen intermolecular interactions in these structures can be considered to be the main cohesive forces responsible for the molecular arrangements in these crystals. The molecular packing of dichlorobenzene isomers, including three polymorphs of 1,4-dichlorobenzene (p-DCB), have been compared and relations between their molecular symmetry, packing arrangements, intermolecular interactions and melting points discussed. The topology of the crystal packing in dichlorobenzene isomers results from the interplay of the molecular shape, steric hindrances and intermolecular interactions. The non-planar arrangement of the dichlorobenzene molecules in the crystal structures can be justified by the distributions of the electrostatic potential on molecular surfaces, which determines electrostatic intermolecular interactions.

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.

Construction of laser-heated diamond anvil cell system for in situ x-ray diffraction study at SPring-8

2001 ◽  
Vol 72 (2) ◽  
pp. 1289 ◽  
Author(s):  
Tetsu Watanuki ◽  
Osamu Shimomura ◽  
Takehiko Yagi ◽  
Tadashi Kondo ◽  
Maiko Isshiki
Keyword(s):  
Diffraction Study ◽  
Diamond Anvil Cell ◽  
Cell System ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diamond Anvil ◽  
Laser Heated

In situ synchrotron X-ray diffraction study of the formation of TaB2 from the elements in a laser heated diamond anvil cell

2010 ◽  
Vol 12 (12) ◽  
pp. 2059-2064 ◽  
Author(s):  
Björn Winkler ◽  
Erick A. Juarez-Arellano ◽  
Alexandra Friedrich ◽  
Lkhamsuren Bayarjargal ◽  
Florian Schröder ◽  
...  
Keyword(s):  
Diffraction Study ◽  
Diamond Anvil Cell ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diamond Anvil ◽  
Laser Heated

scholarly journals Structural Study of δ-AlOOH Up to 29 GPa

Minerals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1055
Author(s):  
Dariia Simonova ◽  
Elena Bykova ◽  
Maxim Bykov ◽  
Takaaki Kawazoe ◽  
Arkadiy Simonov ◽  
...  
Keyword(s):  
Phase Transition ◽  
Synchrotron Radiation ◽  
Equation Of State ◽  
Room Temperature ◽  
Diamond Anvil Cell ◽  
Volume Data ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diamond Anvil ◽  
Murnaghan Equation

A structure and equation of the state of δ-AlOOH has been studied at room temperature, up to 29.35 GPa, by means of single crystal X-ray diffraction in a diamond anvil cell using synchrotron radiation. Above ~10 GPa, we observed a phase transition with symmetry changes from P21nm to Pnnm. Pressure-volume data were fitted with the second order Birch-Murnaghan equation of state and showed that, at the phase transition, the bulk modulus (K0) of the calculated wrt 0 pressure increases from 142(5) to 216(5) GPa.

Equation of state and electrical transport properties of mixture of Li1.2Mn0.54Co0.13Ni0.13O2 and LiNi0.87Co0.09Mn0.03Al0.01O2 at high pressure

2021 ◽  
pp. 2150227
Author(s):  
Lun Xiong ◽  
Pu Tu ◽  
Yongqing Hu ◽  
Xiang Hou ◽  
Shiyun Wu ◽  
...  
Keyword(s):  
High Pressure ◽  
Equation Of State ◽  
Electrical Transport ◽  
Room Temperature ◽  
Diamond Anvil Cell ◽  
Hexagonal Structure ◽  
X Ray Diffraction ◽  
Electrical Transport Properties ◽  
X Ray ◽  
Diamond Anvil

The equation of state (EOS) of mixture of Li[Formula: see text]Mn[Formula: see text]Co[Formula: see text]Ni[Formula: see text]O2 and LiNi[Formula: see text] Co[Formula: see text]Mn[Formula: see text]Al[Formula: see text]O2 was studied by synchrotron radiation X-ray diffraction (XRD) at room-temperature in a diamond anvil cell (DAC). The results showed that the hexagonal structure is maintained to the highest pressure of 23.1 GPa. The bulk modulus and its first derivative obtained from XRD data are [Formula: see text] GPa and [Formula: see text], respectively. In addition, we have investigated the high-pressure electrical conductivity of the mixture of Li[Formula: see text]Mn[Formula: see text]Co[Formula: see text]Ni[Formula: see text]O2 and LiNi[Formula: see text]Co[Formula: see text]Mn[Formula: see text]Al[Formula: see text]O2 to 22.9 GPa in a DAC. It is found that the resistance decreases with the increase of pressure and changes exponentially.

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