scholarly journals Synthesis of magnesium-nitrogen salts of polynitrogen anions

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Dominique Laniel ◽  
Bjoern Winkler ◽  
Egor Koemets ◽  
Timofey Fedotenko ◽  
Maxim Bykov ◽  
...  
Keyword(s):  
High Pressures ◽  
Molecular Nitrogen ◽  
High Energy ◽  
High Energy Density ◽  
Ambient Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Energy Density Materials ◽  
Polynitrogen Compounds ◽  
Laser Heated

Abstract The synthesis of polynitrogen compounds is of fundamental importance due to their potential as environmentally-friendly high energy density materials. Attesting to the intrinsic difficulties related to their formation, only three polynitrogen ions, bulk stabilized as salts, are known. Here, magnesium and molecular nitrogen are compressed to about 50 GPa and laser-heated, producing two chemically simple salts of polynitrogen anions, MgN4 and Mg2N4. Single-crystal X-ray diffraction reveals infinite anionic polythiazyl-like 1D N-N chains in the crystal structure of MgN4 and cis-tetranitrogen N44− units in the two isosymmetric polymorphs of Mg2N4. The cis-tetranitrogen units are found to be recoverable at atmospheric pressure. Our results respond to the quest for polynitrogen entities stable at ambient conditions, reveal the potential of employing high pressures in their synthesis and enrich the nitrogen chemistry through the discovery of other nitrogen species, which provides further possibilities to design improved polynitrogen arrangements.

scholarly journals Carbon clusters formed from shocked benzene

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
D. M. Dattelbaum ◽  
E. B. Watkins ◽  
M. A. Firestone ◽  
R. C. Huber ◽  
R. L. Gustavsen ◽  
...  
Keyword(s):  
High Pressures ◽  
Complex Mixture ◽  
Carbon Clusters ◽  
X Rays ◽  
Reaction Products ◽  
Ambient Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Liquid Benzene ◽  
X Ray Scattering

AbstractBenzene (C6H6), while stable under ambient conditions, can become chemically reactive at high pressures and temperatures, such as under shock loading conditions. Here, we report in situ x-ray diffraction and small angle x-ray scattering measurements of liquid benzene shocked to 55 GPa, capturing the morphology and crystalline structure of the shock-driven reaction products at nanosecond timescales. The shock-driven chemical reactions in benzene observed using coherent XFEL x-rays were a complex mixture of products composed of carbon and hydrocarbon allotropes. In contrast to the conventional description of diamond, methane and hydrogen formation, our present results indicate that benzene’s shock-driven reaction products consist of layered sheet-like hydrocarbon structures and nanosized carbon clusters with mixed sp2-sp3 hybridized bonding. Implications of these findings range from guiding shock synthesis of novel compounds to the fundamentals of carbon transport in planetary physics.

scholarly journals Synthesis of clathrate cerium superhydride CeH9 at 80-100 GPa with atomic hydrogen sublattice

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Nilesh P. Salke ◽  
M. Mahdi Davari Esfahani ◽  
Youjun Zhang ◽  
Ivan A. Kruglov ◽  
Jianshi Zhou ◽  
...  
Keyword(s):  
Atomic Hydrogen ◽  
High Pressures ◽  
Structure Stability ◽  
X Ray Diffraction ◽  
Detailed Chemistry ◽  
X Ray ◽  
3 Dimensional ◽  
Diamond Anvil ◽  
Laser Heated ◽  
Very High

Abstract Hydrogen-rich superhydrides are believed to be very promising high-Tc superconductors. Recent experiments discovered superhydrides at very high pressures, e.g. FeH5 at 130 GPa and LaH10 at 170 GPa. With the motivation of discovering new hydrogen-rich high-Tc superconductors at lowest possible pressure, here we report the prediction and experimental synthesis of cerium superhydride CeH9 at 80–100 GPa in the laser-heated diamond anvil cell coupled with synchrotron X-ray diffraction. Ab initio calculations were carried out to evaluate the detailed chemistry of the Ce-H system and to understand the structure, stability and superconductivity of CeH9. CeH9 crystallizes in a P63/mmc clathrate structure with a very dense 3-dimensional atomic hydrogen sublattice at 100 GPa. These findings shed a significant light on the search for superhydrides in close similarity with atomic hydrogen within a feasible pressure range. Discovery of superhydride CeH9 provides a practical platform to further investigate and understand conventional superconductivity in hydrogen rich superhydrides.

3D high-energy-density and low sensitivity materials: synthesis, structure and physicochemical properties of an azide–Cu(ii) complex with 3,5-dinitrobenzoic acid

RSC Advances ◽  
2014 ◽  
Vol 4 (31) ◽  
pp. 16087-16093 ◽  
Author(s):  
Xiangyu Liu ◽  
Qi Yang ◽  
Zhiyong Su ◽  
Sanping Chen ◽  
Gang Xie ◽  
...  
Keyword(s):  
Energy Density ◽  
Coordination Polymer ◽  
Physicochemical Properties ◽  
Single Crystal ◽  
High Energy ◽  
High Energy Density ◽  
X Ray Diffraction ◽  
Materials Synthesis ◽  
X Ray ◽  
Low Sensitivity

A novel 3D energetic coordination polymer of azide–Cu(ii), Cu(3,5-DNBA)(N3), was synthesized and structurally characterized by single crystal X-ray diffraction, where 3,5-DNBA represents 3,5-dinitrobenzoic acid.

Lithium superionic conductors Li10MP2O12 (M = Ge, Si)

2018 ◽  
Vol 11 (02) ◽  
pp. 1850039 ◽  
Author(s):  
Shufeng Song ◽  
Zhencai Dong ◽  
Fan Deng ◽  
Ning Hu
Keyword(s):  
Room Temperature ◽  
High Energy ◽  
High Energy Density ◽  
Superionic Conductors ◽  
X Ray Diffraction ◽  
Melt Quenching ◽  
Lithium Ions ◽  
X Ray ◽  
Migration Mechanism ◽  
Dc Polarization

The exploration for superionic conductors with new structures and compositions is challengeable for developing safer and high-energy-density batteries. Here, we report lithium superionic conductors with the compositions of Li[Formula: see text]GeP2O[Formula: see text] and Li[Formula: see text]SiP2O[Formula: see text]. The materials are prepared by melt-quenching and characterized by X-ray diffraction (XRD), AC impedance, DC polarization and cyclic voltammetry. Both germanium and silicon members demonstrate same orders of magnitude of bulk and grain-boundary conductivities of 10[Formula: see text] S[Formula: see text]cm[Formula: see text] at room temperature. The crystal structure is investigated by the Rietveld refinement of powder XRD and the migration mechanism of lithium ions is proposed.

scholarly journals Nitrogen-Rich Carbon Nitrides as Novel High Energy Density Materials

2014 ◽  
Vol 70 (a1) ◽  
pp. C758-C758
Author(s):  
Dominique Laniel ◽  
Elena Sebastiao ◽  
Cyril Cook ◽  
Muralee Murugesu ◽  
Serge Desgreniers
Keyword(s):  
Raman Spectroscopy ◽  
Energy Density ◽  
Energetic Materials ◽  
Hexagonal Lattice ◽  
High Energy ◽  
Unit Cell ◽  
High Density ◽  
High Energy Density ◽  
X Ray Diffraction ◽  
X Ray

Nitrogen-rich carbon nitride materials hold the promise of constituting novel high density energetic materials if recoverable as metastable polymeric networks of single-bonded atoms at ambient conditions. Upon transition to a lowest-energy configuration, this high pressure synthesized nitrogen-heavy material would release a large amount of energy. In this work, two nitrogen-rich molecular precursors, namely, 5'-bis(1H-tetrazolyl)amine (BTA) and cyanuric triazide (CTA), were studied in their condensed states at elevated pressures and room temperature. Powder x-ray diffraction using synchrotron radiation and micro-Raman spectroscopy were carried out to pressures as high as 12.9 and 59.6 GPa, for BTA and CTA, respectively. In our study, dense BTA is shown to conserve its room condition crystalline structure, an orthorhombic unit cell (Pbca), up to the highest pressure. In the case of CTA, results of Raman spectroscopy and x-ray diffraction indicate structural changes between 29.6 and 33.4 GPa. From numerical simulations of dense CTA [1], a phase transition into either tritetrazole (hexagonal lattice, P-6) or the sought-after polymeric CTA (monoclinic lattice, P21) is expected to take place at a pressure close to 30 GPa. Preliminary results of x-ray diffraction data indicate a transition from a hexagonal to a monoclinic unit cell with parameters similar to those predicted. Moreover, theoretically calculated polymeric nitrogen Raman peaks [2] are well matched to those observed for the high-density phase of CTA [1]. Studies of BTA and CTA under extreme conditions provide a deeper understanding of the behaviour of dense nitrogen-rich materials and guidance for further developments of high energy density compounds.

High-quality structures at high pressure? Insights from inclusions in diamonds

2016 ◽  
Vol 231 (8) ◽  
Author(s):  
Ross J. Angel ◽  
Sula Milani ◽  
Matteo Alvaro ◽  
Fabrizio Nestola
Keyword(s):  
High Pressure ◽  
Single Crystal ◽  
High Pressures ◽  
Dominant Factor ◽  
Good Precision ◽  
Ambient Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Experimental Protocols ◽  
Diamond Anvil

AbstractWe describe the experimental protocols necessary to measure the crystal structures of minerals trapped within diamonds by single-crystal X-ray diffraction to the same quality as obtained from minerals studied at ambient conditions. The results show that corrections for X-ray absorption in complex cases can be made with good precision. Comparison of the refined structure of a single-crystal olivine inclusion inside a diamond with the structure of a similar olivine held in a high-pressure diamond-anvil cell shows that data resolution, not the correction for absorption effects, is the dominant factor in influencing the quality of structures determined at high pressures by single-crystal X-ray diffraction.

scholarly journals Experimental Issues in In-Situ Synchrotron X-Ray Diffraction at High Pressure and Temperature by Using a Laser-Heated Diamond-Anvil Cell

1997 ◽  
Vol 499 ◽  
Author(s):  
C. S. Yoo ◽  
H. Cynn ◽  
A. Campbell ◽  
J.-Z. Hu
Keyword(s):  
Diamond Anvil Cell ◽  
High Pressures ◽  
Thermal Gradients ◽  
X Ray Diffraction ◽  
High Pressure And Temperature ◽  
X Ray ◽  
Diamond Anvil ◽  
Integrated Technique ◽  
Laser Heated

ABSTRACTAn integrated technique of diamond-anvil cell, laser-heating and synchrotron x-ray diffraction technologies is capable of structural investigation of condensed matter in an extended region of high pressures and temperatures above 100 GPa and 3000 K. The feasibility of this technique to obtain reliable data, however, strongly depends on several experimental issues, including optical and x-ray setups, thermal gradients, pressure homogeneity, preferred orientation, and chemical reaction. In this paper, we discuss about these experimental issues together with future perspectives of this technique for obtaining accurate data.

scholarly journals Conceptual design of initial opacity experiments on the national ignition facility

2017 ◽  
Vol 83 (1) ◽  
Author(s):  
R. F. Heeter ◽  
J. E. Bailey ◽  
R. S. Craxton ◽  
B. G. DeVolder ◽  
E. S. Dodd ◽  
...  
Keyword(s):  
Inertial Confinement Fusion ◽  
High Energy ◽  
High Energy Density ◽  
Inertial Confinement ◽  
X Rays ◽  
X Ray ◽  
Confinement Fusion ◽  
Final Design ◽  
Laser Heated ◽  
Point Projection

Accurate models of X-ray absorption and re-emission in partly stripped ions are necessary to calculate the structure of stars, the performance of hohlraums for inertial confinement fusion and many other systems in high-energy-density plasma physics. Despite theoretical progress, a persistent discrepancy exists with recent experiments at the Sandia Z facility studying iron in conditions characteristic of the solar radiative–convective transition region. The increased iron opacity measured at Z could help resolve a longstanding issue with the standard solar model, but requires a radical departure for opacity theory. To replicate the Z measurements, an opacity experiment has been designed for the National Facility (NIF). The design uses established techniques scaled to NIF. A laser-heated hohlraum will produce X-ray-heated uniform iron plasmas in local thermodynamic equilibrium (LTE) at temperatures ${\geqslant}150$ eV and electron densities ${\geqslant}7\times 10^{21}~\text{cm}^{-3}$. The iron will be probed using continuum X-rays emitted in a ${\sim}200$ ps, ${\sim}200~\unicode[STIX]{x03BC}\text{m}$ diameter source from a 2 mm diameter polystyrene (CH) capsule implosion. In this design, $2/3$ of the NIF beams deliver 500 kJ to the ${\sim}6$ mm diameter hohlraum, and the remaining $1/3$ directly drive the CH capsule with 200 kJ. Calculations indicate this capsule backlighter should outshine the iron sample, delivering a point-projection transmission opacity measurement to a time-integrated X-ray spectrometer viewing down the hohlraum axis. Preliminary experiments to develop the backlighter and hohlraum are underway, informing simulated measurements to guide the final design.

scholarly journals Recognition of V3+/V4+/V5+ Multielectron Reactions in Na3V(PO4)2: A Potential High Energy Density Cathode for Sodium-Ion Batteries

Molecules ◽  
2020 ◽  
Vol 25 (4) ◽  
pp. 1000 ◽  
Author(s):  
Rui Liu ◽  
Ziteng Liang ◽  
Yuxuan Xiang ◽  
Weimin Zhao ◽  
Haodong Liu ◽  
...  
Keyword(s):  
Solid State ◽  
Energy Density ◽  
High Energy ◽  
Sodium Ion ◽  
High Energy Density ◽  
Sodium Ion Batteries ◽  
X Ray Diffraction ◽  
Solid State Method ◽  
X Ray ◽  
Open Question

Na3V(PO4)2 was reported recently as a novel cathode material with high theoretical energy density for Sodium-ion batteries (SIBs). However, whether V3+/V4+/V5+ multielectron reactions can be realized during the charging process is still an open question. In this work, Na3V(PO4)2 is synthesized by using a solid-state method. Its atomic composition and crystal structure are verified by X-ray diffraction (XRD) and neutron diffraction (ND) joint refinement. The electrochemical performance of Na3V(PO4)2 is evaluated in two different voltage windows, namely 2.5–3.8 and 2.5–4.3 V. 51V solid-state NMR (ssNMR) results disclose the presence of V5+ in Na2−xV(PO4)2 when charging Na3V(PO4)2 to 4.3 V, confirming Na3V(PO4)2 is a potential high energy density cathode through realization of V3+/V4+/V5+ multielectron reactions.

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