Ti-V-C-Based Alloy with a FCC Lattice Structure for Hydrogen Storage

Here we report a Ti50V50-10 wt.% C alloy with a unique lattice and microstructure for hydrogen storage development. Different from a traditionally synthesized Ti50V50 alloy prepared by a melting method and having a body-centered cubic (BCC) structure, this Ti50V50-C alloy synthesized by a mechanical alloying method is with a face-centered cubic (FCC) structure (space group: Fm-3m No. 225). The crystalline size is 60 nm. This alloy may directly absorb hydrogen near room temperature without any activation process. Mechanisms of the good kinetics from lattice and microstructure aspects were discussed. Findings reported here may indicate a new possibility in the development of future hydrogen storage materials.

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Microstructure of Liquid Co50Ni50 During Rapid Solidification

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2020.18870 ◽

2020 ◽

Vol 20 (12) ◽

pp. 7593-7600 ◽

Cited By ~ 1

Author(s):

Min Li ◽

Quan Xie ◽

Shan Li

Keyword(s):

Rapid Solidification ◽

Cluster Structure ◽

Solidification Process ◽

Face Centered Cubic ◽

Index Method ◽

Bond Type ◽

Bcc Structure ◽

Hcp Structure ◽

Face Centered ◽

Fcc Structure

The rapid solidification process of Co50Ni50 alloy was simulated by molecular dynamics method, and the formation and evolution characteristics of cluster structure in the solidification process were analyzed by the pair distribution function, Honeycutt–Andersen bond type index method and the largest standard cluster. The results show that during the solidification process with a cooling rate of 1×1012 K·‐1, the probability of mutual bond formation between Co–Co atoms is always greater than that of Ni–Ni, and the formation of the 1421 bond type is dominant in the crystalline structure. The inflection point of the characteristic bond type 1421 varies with the crystalline transition temperature Tg of the system. The Co–Ni alloy is mainly composed of a face-centered cubic atomic group composed of the 1421 bond type. Meanwhile, there will also be a small amount of hcp structure and a smaller amount of bcc structure. Further analysis revealed that the formation of the fcc structure requires the fast decomposition of TCP structures (at 1450 K). That is to say, the TCP structure must be disassembled before the fcc structure is formed. These findings are useful to provide important guidance for the crystallization of Co50Ni50 alloy under rapid cooling in the experiment.

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Effects of C Addition on the Microstructures of As-Cast Cu–Fe–P Alloys

Materials ◽

10.3390/ma12172772 ◽

2019 ◽

Vol 12 (17) ◽

pp. 2772 ◽

Cited By ~ 1

Author(s):

Chen ◽

Hu ◽

Guo ◽

Zou ◽

Liu ◽

...

Keyword(s):

Orientation Relationship ◽

Supersaturated Solid Solution ◽

Face Centered Cubic ◽

Body Centered Cubic ◽

Matrix Microstructure ◽

The Matrix ◽

Bcc Structure ◽

The Difference ◽

Face Centered ◽

Fcc Structure

Effects of C addition on the microstructures of as-cast Cu–Fe–P (mass fraction) alloys were systematically investigated. The results show that C addition can refine the matrix microstructure and make Fe particles finer. The Fe particles observed in both the non-C-alloyed and C-alloyed specimens are α-Fe particles, which possess a body-centered cubic (bcc) structure with a Nishiyama–Wassermann orientation relationship with the matrix. C is reported to be an γ-Fe stabilizer in the literature. The reason for the difference between the phases of Fe particles observed in this study, and that reported in the literature, are finally discussed. Additionally, C addition facilitates the decomposition of the supersaturated solid solution which occurs by the simultaneous precipitation of very fine Fe particles. Such initial decomposition product has an face-centered cubic (fcc) structure with a cube-on-cube orientation relationship with the matrix.

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Configuration Optimization Design of Ti6Al4V Lattice Structure Formed by SLM

Materials ◽

10.3390/ma11101856 ◽

2018 ◽

Vol 11 (10) ◽

pp. 1856 ◽

Cited By ~ 12

Author(s):

Long Bai ◽

Junfang Zhang ◽

Xiaohong Chen ◽

Changyan Yi ◽

Rui Chen ◽

...

Keyword(s):

Mechanical Properties ◽

Optimization Design ◽

Lattice Structure ◽

Control Group ◽

Face Centered Cubic ◽

Lattice Structures ◽

Low Weight ◽

Configuration Generation ◽

Bcc Structure ◽

Face Centered

Previous studies have revealed the influence of various lattice structures on the material density and mechanical properties. However, the majority of the topologies that are considered as study objects directly refer to metal/non-crystal lattice cell configurations. Therefore, this paper proposes a configuration generation approach for generating a lattice structure, which can obtain a lattice configuration that enjoys the advantages of both ultra-low weight and favorable mechanical properties. Based on this approach, a new type of face-centered cubic lattice (all face-centered cubic, AFCC) structure with comprehensively optimal properties in terms of mass and mechanical properties is obtained. The experimental samples are formed with Ti6Al4V by the selective laser melting (SLM) method. Quasi-static uniaxial compression performance experiments and finite element analysis (FEA) are conducted on an AFCC structure and the control group body-centered cubic (BCC) structure. The results demonstrates that our optimized AFCC lattice structure is superior to the BCC structure, with elastic modulus and yield limit increases of 143% and 120%, respectively. For the same degree of deformation, the energy absorbed increases approximately 2.4 times. The AFCC demonstrates significant advantages in terms of its mechanical properties and anti-explosion impact resistance while maintaining favorable ultra-low weight, which validates the hypothesis that the proposed configuration generation approach can provide guidance for the design and further research on ultra-light lattice structures in related fields.

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Epitaxial Ni nanoparticles on CaF2(001), (110) and (111) surfaces studied by three-dimensional RHEED, GIXD and GISAXS reciprocal-space mapping techniques

Journal of Applied Crystallography ◽

10.1107/s160057671700512x ◽

2017 ◽

Vol 50 (3) ◽

pp. 830-839 ◽

Cited By ~ 4

Author(s):

S. M. Suturin ◽

V. V. Fedorov ◽

A. M. Korovin ◽

N. S. Sokolov ◽

A. V. Nashchekin ◽

...

Keyword(s):

Lattice Structure ◽

Three Dimensional ◽

Grazing Incidence ◽

High Energy ◽

Reciprocal Space ◽

Mapping Technique ◽

Face Centered Cubic ◽

X Ray ◽

Cubic Lattice ◽

Face Centered

The development of growth techniques aimed at the fabrication of nanoscale heterostructures with layers of ferroic 3dmetals on semiconductor substrates is very important for their potential usage in magnetic media recording applications. A structural study is presented of single-crystal nickel island ensembles grown epitaxially on top of CaF2/Si insulator-on-semiconductor heteroepitaxial substrates with (111), (110) and (001) fluorite surface orientations. The CaF2buffer layer in the studied multilayer system prevents the formation of nickel silicide, guides the nucleation of nickel islands and serves as an insulating layer in a potential tunneling spin injection device. The present study, employing both direct-space and reciprocal-space techniques, is a continuation of earlier research on ferromagnetic 3dtransition metals grown epitaxially on non-magnetic and magnetically ordered fluorides. It is demonstrated that arrays of stand-alone faceted nickel islands with a face-centered cubic lattice can be grown controllably on CaF2surfaces of (111), (110) and (001) orientations. The proposed two-stage nickel growth technique employs deposition of a thin seeding layer at low temperature followed by formation of the islands at high temperature. The application of an advanced three-dimensional mapping technique exploiting reflection high-energy electron diffraction (RHEED) has proved that the nickel islands tend to inherit the lattice orientation of the underlying fluorite layer, though they exhibit a certain amount of {111} twinning. As shown by scanning electron microscopy, grazing-incidence X-ray diffraction (GIXD) and grazing-incidence small-angle X-ray scattering (GISAXS), the islands are of similar shape, being faceted with {111} and {100} planes. The results obtained are compared with those from earlier studies of Co/CaF2epitaxial nanoparticles, with special attention paid to the peculiarities related to the differences in lattice structure of the deposited metals: the dual-phase hexagonal close-packed/face-centered cubic lattice structure of cobalt as opposed to the single-phase face-centered cubic lattice structure of nickel.

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Potential high-Tc superconducting lanthanum and yttrium hydrides at high pressure

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1704505114 ◽

2017 ◽

Vol 114 (27) ◽

pp. 6990-6995 ◽

Cited By ~ 214

Author(s):

Hanyu Liu ◽

Ivan I. Naumov ◽

Roald Hoffmann ◽

N. W. Ashcroft ◽

Russell J. Hemley

Keyword(s):

Group Structure ◽

High Temperature Superconductors ◽

Face Centered Cubic ◽

Superconducting Transition ◽

High Tc ◽

Structure Search ◽

Systematic Structure ◽

Face Centered ◽

Fcc Structure ◽

Very High

A systematic structure search in the La–H and Y–H systems under pressure reveals some hydrogen-rich structures with intriguing electronic properties. For example, LaH10 is found to adopt a sodalite-like face-centered cubic (fcc) structure, stable above 200 GPa, and LaH8 a C2/m space group structure. Phonon calculations indicate both are dynamically stable; electron phonon calculations coupled to Bardeen–Cooper–Schrieffer (BCS) arguments indicate they might be high-Tc superconductors. In particular, the superconducting transition temperature Tc calculated for LaH10 is 274–286 K at 210 GPa. Similar calculations for the Y–H system predict stability of the sodalite-like fcc YH10 and a Tc above room temperature, reaching 305–326 K at 250 GPa. The study suggests that dense hydrides consisting of these and related hydrogen polyhedral networks may represent new classes of potential very high-temperature superconductors.

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In Situ Synthesis of Polyaniline Based Ceramic Wastes Composites: Dielectric and Electrical Properties

10.21203/rs.3.rs-1111541/v1 ◽

2021 ◽

Author(s):

M. Sohail ◽

Adnan Shahzad ◽

Mian Gul Sayed ◽

Ihsan Ullah ◽

M. Omer ◽

...

Keyword(s):

Composite Material ◽

High Frequency ◽

Room Temperature ◽

In Situ Synthesis ◽

Face Centered Cubic ◽

Dielectric Analysis ◽

Photovoltaic Detectors ◽

Pani Composite ◽

Face Centered

Abstract In the present study, ceramic wastes collected from the premises of industrial zone in Peshawar, KP Pakistan were investigated. An effort has been made to recycle and use the ceramic wastes as fillers in polymeric composites. The negative cost ceramic wastes were purified and activated thermally. The elemental composition and pellets of the wastes were investigated through SEM/EDX analysis. Waste/Polyaniline (PANI) composite was synthesized via in-situ free radical polymerization technique. SEM of the composites showed the uniform distribution of fillers particles in the PANI matrix. XRD studies confirmed that the prepared composite material had a face- centered cubic geometry with distinct preferential orientations. Dielectric analysis showed that the materials exhibit active performance at high frequency regions (3MHz to 3GHz) at room temperature. The results show decrease in dielectric losses and capacitance (1.6 pF) at high frequency regions. AC conductivity of the composite has been increased up to 37.95 Scm-1. This revealed the effect of PANI on the ceramic wastes while increasing its conductance performance. This suggests that the composite material can be investigated for use in photovoltaic detectors, electro-responsive capacitors and power applications.

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Vanishing of room-temperature slip avalanches in a face-centered-cubic high-entropy alloy by ultrafine grain formation

Scripta Materialia ◽

10.1016/j.scriptamat.2018.06.034 ◽

2018 ◽

Vol 155 ◽

pp. 99-103 ◽

Cited By ~ 4

Author(s):

Jian Qiang ◽

Koichi Tsuchiya ◽

Haoyan Diao ◽

Peter K. Liaw

Keyword(s):

Room Temperature ◽

Ultrafine Grain ◽

High Entropy Alloy ◽

Face Centered Cubic ◽

High Entropy ◽

Grain Formation ◽

Face Centered

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Generalization of the Unified Analytic Melt-Shear Model to Multi-Phase Materials: Molybdenum as an Example

Crystals ◽

10.3390/cryst9020086 ◽

2019 ◽

Vol 9 (2) ◽

pp. 86 ◽

Cited By ~ 2

Author(s):

Leonid Burakovsky ◽

Darby Luscher ◽

Dean Preston ◽

Sky Sjue ◽

Diane Vaughan

Keyword(s):

Shear Modulus ◽

Solid Phase ◽

Model Parameters ◽

Quantum Molecular Dynamics ◽

Face Centered Cubic ◽

Shear Model ◽

Bcc Structure ◽

Face Centered ◽

Multi Phase ◽

Theoretical Results

The unified analytic melt-shear model that we introduced a decade ago is generalized to multi-phase materials. A new scheme for calculating the values of the model parameters for both the cold ( T = 0 ) shear modulus ( G ) and the melting temperature at all densities ( ρ ) is developed. The generalized melt-shear model is applied to molybdenum, a multi-phase material with a body-centered cubic (bcc) structure at low ρ which loses its dynamical stability with increasing pressure (P) and is therefore replaced by another (dynamically stable) solid structure at high ρ . One of the candidates for the high- ρ structure of Mo is face-centered cubic (fcc). The model is compared to (i) our ab initio results on the cold shear modulus of both bcc-Mo and fcc-Mo as a function of ρ , and (ii) the available theoretical results on the melting of bcc-Mo and our own quantum molecular dynamics (QMD) simulations of one melting point of fcc-Mo. Our generalized model of G ( ρ , T ) is used to calculate the shear modulus of bcc-Mo along its principal Hugoniot. It predicts that G of bcc-Mo increases with P up to ∼240 GPa and then decreases at higher P. This behavior is intrinsic to bcc-Mo and does not require the introduction of another solid phase such as Phase II suggested by Errandonea et al. Generalized melt-shear models for Ta and W also predict an increase in G followed by a decrease along the principal Hugoniot, hence this behavior may be typical for transition metals with ambient bcc structure that dynamically destabilize at high P. Thus, we concur with the conclusion reached in several recent papers (Nguyen et al., Zhang et al., Wang et al.) that no solid-solid phase transition can be definitively inferred on the basis of sound velocity data from shock experiments on Mo. Finally, our QMD simulations support the validity of the phase diagram of Mo suggested by Zeng et al.

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Pressure-Induced Dimerization of C60 at Room Temperature as Revealed by an In Situ Spectroscopy Study Using an Infrared Laser

Crystals ◽

10.3390/cryst10030182 ◽

2020 ◽

Vol 10 (3) ◽

pp. 182 ◽

Cited By ~ 1

Author(s):

Bing Li ◽

Jinbo Zhang ◽

Zhipeng Yan ◽

Meina Feng ◽

Zhenhai Yu ◽

...

Keyword(s):

Room Temperature ◽

Infrared Laser ◽

Face Centered Cubic ◽

X Ray Diffraction ◽

Simple Cubic ◽

Excitation Laser ◽

Face Centered ◽

830 Nm Laser ◽

Structure Evaluation

Using in situ high-pressure Raman spectroscopy and X-ray diffraction, the polymerization and structure evaluation of C60 were studied up to 16 GPa at room temperature. The use of an 830 nm laser successfully eliminated the photo-polymerization of C60, which has interfered with the pressure effect in previous studies when a laser with a shorter wavelength was used as excitation. It was found that face-centered cubic (fcc) structured C60 transformed into simple cubic (sc) C60 due to the hint of free rotation for the C60 at 0.3 GPa. The pressure-induced dimerization of C60 was found to occur at about 3.2 GPa at room temperature. Our results suggest the benefit and importance of the choice of the infrared laser as the excitation laser.

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