A5037607144- Iron-based superconductors research
- Physics of Superconductivity and Magnetism
- Advanced Photocatalysis Techniques
- Speech and Audio Processing
- Superconductivity in MgB2 and Alloys
- Gas Sensing Nanomaterials and Sensors
- Corporate Taxation and Avoidance
- Speech Recognition and Synthesis
- Copper-based nanomaterials and applications
- TiO2 Photocatalysis and Solar Cells
- Liquid Crystal Research Advancements
- Phonetics and Phonology Research
- Blind Source Separation Techniques
- Advanced Adaptive Filtering Techniques
- Advanced Materials and Mechanics
- Graphene research and applications
- Linguistic Variation and Morphology
- Nanomaterials for catalytic reactions
- ZnO doping and properties
- Rare-earth and actinide compounds
- Spectroscopy and Chemometric Analyses
- Fiber-reinforced polymer composites
- Surfactants and Colloidal Systems
- Air Quality and Health Impacts
- Industrial Technology and Control Systems
Northeast Petroleum University
2012-2024
State Grid Corporation of China (China)
2024
Horological Research Institute of Light Industry
2024
Xi'an Polytechnic University
2024
Taiyuan University of Technology
2024
Tianjin University of Finance and Economics
2024
PLA Rocket Force University of Engineering
2018-2023
Chinese University of Hong Kong
2023
China University of Geosciences (Beijing)
2023
Xi'an High Tech University
2010-2022
We present detailed measurements of the longitudinal resistivity ${\ensuremath{\rho}}_{xx}(T,H)$ and upper critical field ${H}_{c2}$ ${\text{NdFeAsO}}_{0.7}{\text{F}}_{0.3}$ single crystals in strong dc pulsed magnetic fields up to 45 60 T, respectively. found that scale is comparable ${H}_{c2}\ensuremath{\sim}100\text{ }\text{T}$ high-${T}_{c}$ cuprates. ${H}_{c2}(T)$ parallel $c$ axis exhibits a pronounced upward curvature similar what was extracted from earlier on polycrystalline...
Less than two years after the discovery of high temperature superconductivity in oxypnictide LaFeAs(O,F) several families superconductors based on Fe layers (1111, 122, 11, 111) are available. They share characteristics with cuprate that compromise easy applications, such as layered structure, small coherence length, and unconventional pairing, On other hand Fe-based have metallic parent compounds, their electronic anisotropy is generally smaller does not strongly depend level doping,...
The effect of the 2-methylimidazole (Hmim)/zinc nitrate hexahydrate (Zn) molar ratio on physicochemical characteristics zeolitic imidazolate framework-8 (ZIF-8) was investigated. ZIF-8 crystals were synthesized by mixing Hmim with Zn at room temperature without any additives in methanol solution. It found that Hmim/Zn had significant influence crystallinity, yield, particle size and porosity ZIF-8. samples low showed a cubic shape, whereas higher ratios truncated rhombic dodecahedron or...
Zeolitic imidazolate framework-8 (ZIF-8) was introduced on the surface of fibers a non-woven fabric made polyethylene terephthalate (PET). The phase structure, morphology, textural properties and chemical structure were studied using X-ray diffraction (XRD), scanning electron microscopy (SEM), nitrogen (N2) adsorption analyzer Fourier transform infrared spectroscopy (FTIR). XRD, SEM FTIR results indicated that ZIF-8 had been successfully coated PET fibers. N2 analyses suggested addition...
We report a systematic investigation, together with theoretical analysis, of the resistivity and Hall effect in single crystals $\text{Ba}{({\text{Fe}}_{1\ensuremath{-}x}{\text{Co}}_{x})}_{2}{\text{As}}_{2}$ over wide doping range. find surprisingly great disparity between relaxation rates holes electrons excess one order magnitude low-doping, low-temperature regime. The ratio electron to hole mobilities diminishes temperature (away from magnetically ordered state) becomes more conventional....
By using flux method, we have grown single crystals of NdFeAsO0.82F0.18 at ambient pressures. Resistive measurements reveal a surprising discovery that the anisotropy Γ=(mc∕mab)1∕2 is below 5, which much smaller than theoretically calculated value. The data measured up to 400K show curved feature, prevents conjectured linear behavior for an unconventional metal. upper critical fields determined based on Werthamer–Helfand–Hohenberg formula [N. R. Werthamer et al., Phys. Rev. 147, 295 (1966)]...
By substituting the Fe with $4d$- and $5d$-transition metals Rh, Ir, Pd in ${\text{SrFe}}_{2}{\text{As}}_{2}$, we have successfully synthesized a series of superconductors ${\text{SrFe}}_{2\ensuremath{-}x}{M}_{x}{\text{As}}_{2}$ ($M=\text{Rh}$, Pd) explored phase diagrams them. The systematic evolution lattice constants indicated that part ions were replaced by transition Pd. increasing doping content Pd, antiferromagnetic (AF) state parent is suppressed progressively superconductivity...
Each discovery of a new high temperature superconductor drives the expectation that advanced engineering materials defect structures will enable effective vortex pinning and values electrical current density. Here, we demonstrate single crystals iron-based Ba0.6K0.4Fe2As2 with Tc = 37.5 K can accommodate an unprecedented large concentration strong-pinning defects in form discontinuous nm-sized nanorods no degradation superconducting transition temperature. At 5 K, find critical density...
A new critical-current-by-design paradigm is presented. It aims at predicting the optimal defect landscape in superconductors for targeted applications by elucidating vortex dynamics responsible bulk critical current. To this end, current measurements on commercial high-temperature are combined with large-scale time-dependent Ginzburg-Landau simulations of dynamics.
We have studied the current-carrying capability of high quality epitaxial MgB2 films synthesized using hybrid physical-chemical vapor deposition technique by both transport measurement in nanobridge constrictions and magnetization measurement. An extremely self-field critical current density Jc(0)>108A∕cm2, approaching theoretical depairing MgB2, was observed on a 150nm bridge, indicating an excellent these films. The also showed very Jc.
Hall effect and magnetoresistance have been measured on single crystals of ${\text{NdFeAsO}}_{1\ensuremath{-}x}{\text{F}}_{x}$ with $x=0$ $({T}_{c}=0\text{ }\text{K})$ $x=0.18$ $({T}_{c}=50\text{ }\text{K})$. For the undoped samples, strong temperature dependence were found below about 150 K. The was to be as large 30% at 15 K a magnetic field 9 T. From transport data we that transition near 155 accomplished in two steps: first one occurs which may associated structural transition, second...
We report a comprehensive investigation of the suppression critical temperature Tc NdFeAs(OF) single crystal by alpha-particle irradiation. Our data indicate that irradiation defects produce both nonmagnetic and magnetic scattering, resulting in Kondo-like excess resistance $\Delta\rho(T)\propto ln T$ over 2 decades temperatures above $T_c$. Despite high densities defects, dose at which $T_c$ is suppressed to zero comparable for MgB2 but well corresponding values cuprates.
We have measured the normal state temperature dependence of Hall effect and magnetoresistance in epitaxial ${\mathrm{MgB}}_{2}$ thin films with variable disorders characterized by residual resistance ratio $RRR$ ranging from 4.0 to 33.3. A strong nonlinearity been found clean samples, they decrease gradually increase or temperature. By fitting data theoretical model based on Boltzmann equation ab initio calculations for a four-band system, first time, we derived scattering rates these four...
The in-field critical current of commercial YBa2Cu3O7 coated conductors can be substantially enhanced by post-fabrication irradiation with 4 MeV protons. Irradiation to a fluence 8 × 1016 p/cm2 induces near doubling the in fields 6 T || c at temperature 27 K, field and range interest for applications, such as rotating machinery. A mixed pinning landscape preexisting precipitates twin boundaries small, finely dispersed induced defects may account improved vortex high magnetic fields. Our data...
We report on the systematic evolution of vortex pinning behavior in isovalent doped single crystals BaFe${}_{2}$(As${}_{1\ensuremath{-}x}$P${}_{x}$)${}_{2}$. Proceeding from optimal to overdoped samples, we find a clear transformation magnetization hysteresis fishtail distinct peak effect, followed by reversible and Bean-Livingston surface barriers. Strong point dominates at low fields whereas weak collective determines higher fields. In addition doping effects, show that particle...
Mixed pinning landscapes in superconductors are emerging as an effective strategy to achieve high critical currents high, applied magnetic fields. Here, we use heavy-ion and proton irradiation create correlated point defects explore the vortex behavior of each combined constituent iron-based superconductor Ba0.6K0.4Fe2As2 find that mechanisms non-additive. The major effect p-irradiation mixed is generation field-independent very At 7 T ‖ c 5 K, current density exceeds MA/cm2.
Surfactant vesicles containing monomers in the interior of bilayer were used to template hollow polymer nanocapsules. This study investigated formation surfactant/monomer assemblies by two loading methods, concurrent and diffusion loading. The assembly process resulting aggregates with dynamic light scattering, small angle neutron small-angle X-ray scattering. Acrylic formed a mixture cationic anionic surfactants broad range surfactant ratios. Regions predominant broader for compositions...
Yolk–shell nanostructures, or nanorattles, are created by growing metal nanoparticles exclusively inside hollow porous polymer nanocapsules. Metal ions enter the nanocapsules through size-selective nanopores. Synthesis of is initiated an agent entrapped in Tannic acid, β-cyclodextrin, and polyether dendrimer were used as sacrificial molecules for initiation growth gold nanoparticles. If needed, initiator can be fragmented acid hydrolysis removed from Variations reaction conditions yield...
Nanoprobes for surface-enhanced Raman scattering (SERS) were prepared by creating nanorattles, or yolk-shell structures, containing gold silver nanoparticles entrapped in porous hollow polymer nanocapsules. Controlled permeability of the shells nanocapsules, achieved controlling pore size and/or shell surface functionalization, resulted size- and charge-selective SERS analyses. For example, a trace amount phenanthroline, model analyte, was detected human blood plasma without preprocessing...