A5101804918- MXene and MAX Phase Materials
- Boron and Carbon Nanomaterials Research
- Advanced ceramic materials synthesis
- Metal and Thin Film Mechanics
- Advanced materials and composites
- Intermetallics and Advanced Alloy Properties
- Concrete and Cement Materials Research
- Innovative concrete reinforcement materials
- Aluminum Alloys Composites Properties
- High-pressure geophysics and materials
- Diamond and Carbon-based Materials Research
- Innovations in Concrete and Construction Materials
- Grouting, Rheology, and Soil Mechanics
- Iron-based superconductors research
- Corporate Taxation and Avoidance
- Advanced Chemical Physics Studies
- Microwave Dielectric Ceramics Synthesis
- Hydrogen Storage and Materials
- Ferroelectric and Piezoelectric Materials
- Thermal Expansion and Ionic Conductivity
- Layered Double Hydroxides Synthesis and Applications
- Intellectual Capital and Performance Analysis
- Surface Chemistry and Catalysis
- Advanced Battery Materials and Technologies
- COVID-19 and healthcare impacts
Institute of New Materials
2021-2024
Guangdong Provincial People's Hospital
2023
Guangdong Academy of Agricultural Sciences
2020
Farmland Irrigation Research Institute
2020
China State Construction Engineering (China)
2020
Schlumberger (British Virgin Islands)
2017
Chinese University of Hong Kong
2017
Central China Normal University
2015
Los Alamos National Laboratory
2008-2014
Chinese Academy of Sciences
2005-2013
Among transition metal nitrides, tungsten nitrides possess unique and/or superior chemical, mechanical, and thermal properties. Preparation of these however, is challenging because the incorporation nitrogen into lattice thermodynamically unfavorable at atmospheric pressure. To date, most materials in W–N system are form thin films produced by nonequilibrium processes often poorly crystallized, which severely limits their use diverse technological applications. Here we report synthesis...
An integrated (Cu,Ni)O mesoporous nanowire array that delivers a high specific capacitance has been used to construct high-performance aqueous asymmetric supercapacitors of (Cu,Ni)O<sub>(+)</sub>//AC<sub>(−)</sub>.
Direct atomic resolution observations of the layered stacking characteristics TaC x slabs and Al planes in ternary Ta–Al–C carbides were achieved. Layered compounds have diverse structures. A previously unknown Ta 6 AlC 5 carbide, as well intergrown 2 AlC–Ta 4 3 –Ta structures identified. Theoretical lattice parameters bulk modulus AlC, , are presented. Furthermore, Ta–C bonds much stronger than Ta–Al carbides, which accounts for enhancement with increasing layers.
Single-phase bulk Cr2AlC, a non-Ti-containing carbide with superior expected properties, was successfully fabricated by in-situ hot pressing/solid-liquid reaction process. The process investigated using differential scanning calorimetry. products were characterized X-ray diffraction and electron microscopy. Four distinguished stages of the reactions from Cr, Al, C elemental powders discussed. obtained data are in good agreement calculated ones those JCPDS card No. 29-0017. A new set Xray...
The elastic stiffness and shear deformation mode of Al3BC3, a metal borocarbide containing linear C–B–C units, are studied based on the first-principles total energy calculations. predominant effect units mechanical properties is reported by leading to low modulus. shear-strain resistance originates from as follows: rigid tilt with respect c direction easily, corner-sharing Al5C bipyramid slabs simultaneously slide along basal plane resistance. proposed may be universal for ternary...
Bulk Ta 4 AlC 3 ceramic was prepared by an in situ reaction synthesis/hot‐pressing method using Ta, Al, and C powders as the starting materials. The lattice parameter a new set of X‐ray diffraction data were obtained. physical mechanical properties investigated. is good electrical thermal conductor. flexural strength fracture toughness are 372 MPa 7.7 MPa·m 1/2 , respectively. Typically, plate‐like layered grains contribute to damage tolerance . After indentation up 200 N load, no obvious...
We perform first-principles density functional calculations on a newly discovered tantalum nitride with an orthorhombic ${\mathrm{U}}_{2}{\mathrm{S}}_{3}$ structure to assess its thermodynamic and mechanical stabilities. Our random search unveils tetragonal ${\mathrm{Ta}}_{2}{\mathrm{N}}_{3}$ that is energetically more favorable than at zero pressure. predict the transforms into phase above relatively low pressure of 7.7 GPa. Single-crystal elastic constant reveal mechanically unstable...
The effect of pressure on the crystalline structure and superconducting transition temperature (Tc) 111-type Na1–xFeAs system using in situ high-pressure synchrotron X-ray powder diffraction diamond anvil cell techniques is studied. A pressure-induced tetragonal to isostructural phase was found. systematic evolution FeAs4 tetrahedron as a function based Rietveld refinements patterns obtained. nonmonotonic Tc(P) behavior found correlate with anomalies distance between anion (As) iron layer...
In this study, magnetic biochar nanocomposites (FeC–S) were prepared by employing ethylene glycol as a liquefaction agent of corn stalks and solvent for the solvothermal synthesis approach. The effects urea/Fe3+ molar ratio, final temperature, residence time on properties FeC–S investigated. Magnetic synthesized through pyrolysis chemical co-precipitation method (FeC–P) was employed comparison. As revealed Fourier transform infrared spectroscopy, X-ray diffraction, photoelectron scanning...
In this letter, the full set of elastic coefficients LaPO4 monazite is presented based on first-principles plane-wave pseudopotential total energy method. Mechanical parameters (bulk modulus, shear Young’s moduli, and Poisson’s ratio) are also compared with experimental results for polycrystalline monazite. The responses electronic structure chemical bonds to a series {010}⟨001⟩ strains examined in order study mechanism low strain resistance. show that small moduli originate from...
Raman active phonon frequencies and corresponding vibrational eigenmodes are reported for two M2AlC ceramics, Ti2AlC Cr2AlC, by means of first-principles calculations. The theoretical modes approved the experimental spectrum Ti2AlC. Compared with that Ti3SiC2 counterpart, number is definitely determined chemical formula transition-metal carbide layers; example, TiC0.67 in TiC0.5 M2AlC. All originate from stretching bending Al–M–C covalent bond chains, whereas vibration M–C localized inside...
In this paper, we predicted the possible mechanical properties and presented electronic structure of ${\mathrm{Zr}}_{3}{\mathrm{Al}}_{3}{\mathrm{C}}_{5}$ by means first-principles pseudopotential total energy method. The equation state, elastic parameters (including full set second order coefficients, bulk shear moduli, Young's Poisson's ratio), ideal tensile strengths are reported compared with those binary compound ZrC. Furthermore, bond relaxation breaking under deformation from...
Polycrystalline Zr 2 Al 3 C 4 was fabricated by an in situ reactive hot‐pressing process using zirconium (zirconium hydrides), aluminum, and graphite as starting materials. The investigation on reaction path revealed that the liquid played important role triggering formation of ternary aluminum carbides. mechanical properties at room temperature were measured (Vickers hardness 10.1 GPa, Young's modulus 362 flexural strength 405 MPa, fracture toughness 4.2 MPa·m 1/2 ). electrical resistivity...
An in situ reactive hot‐pressing process using zirconium (zirconium hydride), aluminum, and graphite as staring materials Si Y 2 O 3 additives was used to synthesize bulk Zr Al C 5 ceramics. This method demonstrates the advantages of easy synthesis, lower sintering temperature, high purity density, improved mechanical properties synthesized . Its electrical thermal were measured. Compared with ZrC, has a relatively low hardness (Vickers 12.5 GPa), comparable stiffness (Young's modulus 374...
We report experimental results of phase stability and incompressibility CrN. The obtained bulk moduli for cubic orthorhombic CrN are 257 262 GPa, respectively. These invalidate the conclusion phase-transition-induced elastic softening recently reported based on nonmagnetic simulations [Nature Mater. 8, 947 (2009)]. On other hand, they provide only evidence to support computational models involving local magnetic moment Cr atoms 9, 283 (2010)], indicating that atomic spin has a profound...
Microstructures of oxidized Ti 3 AlC 2 and were investigated using transmission electron microscopy. The presence Ti‐rich precipitates in the Al O oxide scale enrichment grain boundaries identified. High diffusivity carbides contributes to selective oxidation Al. Moreover, adhesive strength between scales substrates exceeds 85 MPa. Strong thermal‐cyclic stability scales.
Abstract Most traditional polycrystalline diamond compact (PDC) cutting elements have a flat table at the end of cylindrically shaped tungsten carbide body. During drilling, engages formation and shears rock layer by layer. A new ridge-shaped element (RDE) has similar cylindrical base; however, is like saddle with an elongated ridge running through center normal to cutter axis. The intended portion, "ridge," fracture shear same time. design intent was create unique that could combine crush...
Silicon nanowires (Si NWs), one-dimensional single crystalline, have recently drawn extensive attention, thanks to their robust applications in electrical and optical devices as well the strengthening of diamond/SiC superhard composites. Here, we conducted high-pressure synchrotron diffraction experiments a diamond anvil cell study phase transitions compressibility Si NWs. Our results revealed that onset pressure for I−II transformation NWs is approximately 2.0 GPa lower than previously...
We investigate the compressibility of nanocrystalline tungsten carbide (nano-WC) using synchrotron x-ray diffraction. Nano-WC displays a bulk modulus (452 GPa) comparable to that diamond; it is 10%–15% larger than previously reported values for WC. This finding consistent with generalized model nanocrystal compressed surface layer. The linear moduli nano-WC along a- and c-axes were determined be 407 546 GPa, respectively. First-principles density functional theory (DFT) calculations confirm...
The structural and mechanical properties of γ-B28 are investigated using first-principles density functional calculations. single-crystal elastic constants calculations show that is mechanically stable under ambient conditions. predicted bulk shear moduli comparable to those boron suboxide, suggesting can be a superhard material. We also obtained the ideal tensile strength for through deformation from regime instability. find breaking B1–B1 B1–B2 bonds responsible failure ⟨100⟩ ⟨010⟩...