scholarly journals Ultrafast X-ray diffraction measurements of shock-compressed iron and iron alloys

2020 ◽  
Author(s):  
Andrew Krygier ◽  
Marion Harmand ◽  
Bruno Albertazzi ◽  
Emma McBride ◽  
Kohei Miyanishi ◽  
...  
Keyword(s):  
Phase Stability ◽  
Density Functional ◽  
Solid Phase ◽  
Dynamic Compression ◽  
Density Functional Theory Calculations ◽  
Rapid Onset ◽  
Great Promise ◽  
X Ray Diffraction ◽  
Static Compression ◽  
X Ray

Abstract The extreme pressures achievable with dynamic compression holds great promise for studying planetary interiors. Phase stability of Fe-Si alloys, which are complex to address, is particularly relevant to understanding telluric planetary cores due to the widely varying properties produced by small changes in Si concentration. Here we report the study of phase stability of pure iron and Fe-Si alloys by x-ray diffraction measurements carried out on shocked samples using an x-ray free electron laser (XFEL). Our setup combined with the brilliance of the XFEL allows us to observe the rapid onset of high-pressure solid-solid phase transformation in Fe and Fe-Si8.5wt%; we observe no such evidence in Fe-Si16wt% up to 110 GPa on the nanosecond timescale. Density Functional Theory calculations provide the conceptual framework to rationalize these observations. Taken together our experiments and calculations support recent dynamic compression measurements and shed light on conflicting static compression results. Our work highlights the need to properly consider the differing intrinsic timescales of the static and dynamic experiments when comparing results, and the complementarity of the techniques in assessing phase diagram and transition mechanisms.

scholarly journals High-Pressure Structural Behavior and Equation of State of Kagome Staircase Compound, Ni3V2O8

Crystals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 910
Author(s):  
Daniel Diaz-Anichtchenko ◽  
Robin Turnbull ◽  
Enrico Bandiello ◽  
Simone Anzellini ◽  
Daniel Errandonea
Keyword(s):  
High Pressure ◽  
Equation Of State ◽  
Density Functional ◽  
Room Temperature ◽  
Ambient Pressure ◽  
Density Functional Theory Calculations ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
A Chain

We report on high-pressure synchrotron X-ray diffraction measurements on Ni3V2O8 at room-temperature up to 23 GPa. According to this study, the ambient-pressure orthorhombic structure remains stable up to the highest pressure reached in the experiments. We have also obtained the pressure dependence of the unit-cell parameters, which reveals an anisotropic compression behavior. In addition, a room-temperature pressure–volume third-order Birch–Murnaghan equation of state has been obtained with parameters: V0 = 555.7(2) Å3, K0 = 139(3) GPa, and K0′ = 4.4(3). According to this result, Ni3V2O8 is the least compressible kagome-type vanadate. The changes of the crystal structure under compression have been related to the presence of a chain of edge-sharing NiO6 octahedral units forming kagome staircases interconnected by VO4 rigid tetrahedral units. The reported results are discussed in comparison with high-pressure X-ray diffraction results from isostructural Zn3V2O8 and density-functional theory calculations on several isostructural vanadates.

A high-pressure study of HfC and nano-crystalline TiC by X-ray diffraction and density functional theory calculations

2020 ◽  
Vol 34 (34) ◽  
pp. 2050393
Author(s):  
Lun Xiong ◽  
Bin Li ◽  
Bi Liang ◽  
Jinxia Zhu ◽  
Hong Yi ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
High Pressure ◽  
Bulk Modulus ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
X Ray ◽  
Nano Crystalline

The equation of state (EOS) of HfC and nanosized TiC at high pressure has been studied by means of synchrotron radiation X-ray diffraction (XRD) in a diamond anvil cell (DAC) at ambient temperature, and density functional theory (DFT) calculations. XRD analysis showed that the cubic structure of HfC and nanosized TiC maintained to the maximum pressures. The XRD data yield a bulk modulus [Formula: see text] GPa with [Formula: see text] of HfC. In addition, the bulk modulus of nanosized TiC derived from XRD data is [Formula: see text] GPa with [Formula: see text].

Investigation of Structural Evolution of Li1.1V3O8 by In Situ X-ray Diffraction and Density Functional Theory Calculations

2017 ◽  
Vol 29 (5) ◽  
pp. 2364-2373 ◽  
Author(s):  
Qing Zhang ◽  
Alexander B. Brady ◽  
Christopher J. Pelliccione ◽  
David C. Bock ◽  
Andrea M. Bruck ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Structural Evolution ◽  
Density Functional Theory Calculations ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
X Ray

scholarly journals Experimental and theoretical charge density distribution in Pigment Yellow 101

2015 ◽  
Vol 17 (6) ◽  
pp. 4677-4686 ◽  
Author(s):  
Jonathan J. Du ◽  
Linda Váradi ◽  
Jinlong Tan ◽  
Yiliang Zhao ◽  
Paul W. Groundwater ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Density Distribution ◽  
Charge Density ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
X Ray Diffraction ◽  
Charge Density Distribution ◽  
Functional Theory ◽  
X Ray ◽  
Multipole Refinement

The charge density distribution in 2,2′-dihydroxy-1,1′-naphthalazine (Pigment Yellow 101; P.Y.101) has been determined using high-resolution X-ray diffraction and multipole refinement, along with density functional theory calculations.

Meso-1,4-phenylene bridged nickel norcorrole dimer

2020 ◽  
Vol 24 (01n03) ◽  
pp. 191-199
Author(s):  
Ji-Young Shin
Keyword(s):  
Density Functional ◽  
Spectroscopic Analysis ◽  
Computational Simulation ◽  
Density Functional Theory Calculations ◽  
Laser Pulses ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
X Ray ◽  
Solid States ◽  
Anti Conformation

Nickel norcorrole dimer 3 linked with a phenylene bridge was prepared by a nickel-mediated homolytic cross-coupling of meso-phenylene bisdipyrrin nickel(II) dimer 2b. The structures of 2b and 3 were elucidated by X-ray diffraction analysis. Each nickel norcorrole fraction of the nickel norcorrole dimer 3 exposed a bowl-like structure, which conserved anti-conformation. Structural distinctions between the monomeric and dimeric nickel norcorroles were established by vibrational spectroscopic analysis and assessed with density functional theory calculations. Enhanced flexibility of the norcorrole planes in solution states of monomeric nickel norcorrole was compromised to that of bowl-shaped norcorroles in the solid states of nickel norcorrole dimer 3, where C[Formula: see text] was the formulated conformation. The deformation of the planarity derived from the objection of laser pulses effectuated vibration shifts of specific Raman-active motions toward a higher-frequency region, as associating with a paratropic nature of the [Formula: see text]-electron delocalization circuit of norcorrole. Computational simulation exposed a reliable drift of the Raman frequencies.

The crystal structure of Zr2NiD4.5

2006 ◽  
Vol 62 (6) ◽  
pp. 972-978 ◽  
Author(s):  
M. H. Sørby ◽  
A. E. Gunnæs ◽  
O. M. Løvvik ◽  
H. W. Brinks ◽  
H. Fjellvåg ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Neutron Diffraction Data ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
X Ray ◽  
Tetrahedral Sites ◽  
Powder Neutron Diffraction ◽  
Powder Neutron Diffraction Data

The crystal structure of Zr2NiD4.5 has been determined by a combination of synchrotron radiation powder X-ray diffraction, electron diffraction and powder neutron diffraction data. Deuterium ordering results in a triclinic supercell given by a super = 6.81560 (7), b super = 8.85137 (9), c super = 8.88007 (10) Å, αsuper = 79.8337 (8), βsuper = 90.0987 (9), γsuper = 90.3634 (9)°, which relates to the non-super unit cell as a super = −a, b super = −b − c, c super = −b + c. The centrosymmetric and fully ordered deuterium sublattice was determined by simulated annealing and Rietveld refinement. Deuterium was found to occupy three types of tetrahedral sites: two that are coordinated by four Zr atoms and one that is coordinated by three Zr atoms and one Ni atom. All D—D distances are longer than 2 Å. The feasibility of the crystal structure was supported by density functional theory calculations.

scholarly journals Boosting the Stability of Boron Peroxides through Subphthalocyanine Coordination

2021 ◽  
Vol 03 (02) ◽  
pp. 141-145
Author(s):  
Jorge Labella ◽  
Elisa López-Serrano ◽  
Tomás Torres
Keyword(s):  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Lewis Base ◽  
Ambient Conditions ◽  
X Ray Diffraction ◽  
Functional Theory ◽  
X Ray ◽  
The Stability ◽  
The Impact ◽  
Structural And Optoelectronic Properties

The great potential of subphthalocyanines (SubPcs) to stabilize boron peroxides has been demonstrated. In particular, a subphthalocyanato boron (III) peroxide has been prepared in good yield via boron triflate. This derivative is remarkably stable under ambient conditions and can be fully characterized. The impact of the peroxide group on the structural and optoelectronic properties of SubPc was examined by NMR and UV/Vis spectroscopies, as well as single-crystal X-ray diffraction analysis. Moreover, density functional theory calculations were performed to explain the experimental results. The reactivity of this peculiar boron peroxide as an oxidant and a Lewis base was also studied.

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