A5010697119- Superconductivity in MgB2 and Alloys
- Physics of Superconductivity and Magnetism
- Iron-based superconductors research
- Graphene research and applications
- Magnesium Alloys: Properties and Applications
- Diamond and Carbon-based Materials Research
- Metal-Organic Frameworks: Synthesis and Applications
- Covalent Organic Framework Applications
- Semiconductor materials and devices
- Carbon Nanotubes in Composites
- Thermal Expansion and Ionic Conductivity
- Advancements in Battery Materials
- Graphene and Nanomaterials Applications
- Supercapacitor Materials and Fabrication
- Electronic and Structural Properties of Oxides
- Membrane Separation and Gas Transport
- Mesoporous Materials and Catalysis
- Organic and Molecular Conductors Research
- High-pressure geophysics and materials
- Engineering Applied Research
- Chalcogenide Semiconductor Thin Films
- Advanced Sensor and Energy Harvesting Materials
- Electromagnetic wave absorption materials
- Copper-based nanomaterials and applications
- Quantum Dots Synthesis And Properties
Institute for Basic Science
2018-2025
Sungkyunkwan University
2007-2021
Korea Institute of Science and Technology
2012-2015
Korean Association Of Science and Technology Studies
2012
Kwangshin University
2008
Abstract Zinc‐based batteries have a high capacity and are safe, cost‐effective, environmentally‐friendly, capable of scalable production. However, dendrite formation poor reversibility hinder their performance. Metal‐organic framework (MOF)‐based Zn anodes made by wet chemistry to address these issues. These MOF‐based exhibit efficiency during plating‐stripping prevent formation, as shown ex situ SEM analysis. The practicality the is demonstrated in aqueous ion batteries, which show...
Turning many into one Single-crystal metal foils are valuable for their surface properties that allow synthesis of materials like graphene. Jin et al. present a strategy creating colossal single-crystal called “contact-free annealing” (see the Perspective by Rollett). The method relies on hanging and heating commercially available, inexpensive, cold-rolled foils. Almost as if magic, polycrystalline grains rotate anneal large sheet with specific crystal orientation. allows creation much...
We report a versatile method to make liquid metal composites by vigorously mixing gallium (Ga) with non-metallic particles of graphene oxide (G-O), graphite, diamond, and silicon carbide that display either paste or putty-like behavior depending on the volume fraction. Unlike Ga, mixtures can be kneaded rolled any surface without leaving residue. By changing temperature, these materials stiffened, softened, and, for G-O-containing composite, even made porous. The putty (GalP) containing...
Abstract Room‐temperature synthesis of 2D graphitic materials (2D‐GMs) remains an elusive aim, especially with electrochemical means. Here, it is shown that liquid metals render this possible as they offer catalytic activity and ultrasmooth templating interface promotes Frank–van der Merwe regime growth, while allowing facile exfoliation due to the absence interfacial forces a nonpolar liquid. The 2D‐GMs are formed at low onset potential can be in situ doped depending on choice organic...
We report the synthesis and characterization of a two-dimensional (2D) MX2Y2-type (M = metal, X, Y N, S, O, X ≠ Y) copper 1,3,5-triamino-2,4,6-benzenetriol metal-organic framework (Cu3(TABTO)2-MOF). The role oxygen in this MOF was investigated. Copper metal is formed along with when done argon as suggested by XRD. When reaction exposed to air vigorous stirring, not observed However, if there no then formed, we learned that because allowed enter solvent due formation film at air/water...
We report the synthesis and characterization of a two-dimensional (2D) conjugated Ni(II) tetraaza[14]annulene-linked metal organic framework (NiTAA-MOF) where NiTAA is macrocyclic MN4 (M = metal, N nitrogen) compound. The structure NiTAA-MOF was elucidated by Fourier-transform infrared, X-ray photoemission, diffraction spectroscopies, in combination with density functional theory (DFT) calculations. When chemically oxidized iodine, insulating bulk (σ < 10-10 S/cm) exhibits an electrical...
A macroscopic film (2.5 cm × 2.5 cm) made by layer-by-layer assembly of 100 single-layer polycrystalline graphene films is reported. The layers are transferred and stacked one using a wet process that leads to layer defects interstitial contamination. Heat-treatment the sample up 2800 °C results in removal contaminants healing defects. resulting freestanding with near-perfect in-plane crystallinity but mixed stacking order through thickness, which separates it from all existing carbon...
Abstract The development of different classes porous polymers by linking organic molecules using new chemistries still remains a great challenge. Herein, we introduce for the first time synthesis covalent quinazoline networks (CQNs) an ionothermal protocol. Zinc chloride (ZnCl 2 ) was used as solvent and catalyst condensation aromatic ortho ‐aminonitriles to produce tricycloquinazoline linkages. resulting CQNs show high porosity with surface area up 1870 m g −1 . Varying temperature amount...
The production of multifunctional pure organic materials that combine different sizes pores and a large number electron spins is highly desirable due to their potential applications as polarizers for dynamic nuclear polarization-nuclear magnetic resonance catalysts separation media. Here, we report polychlorotriphenylmethyl radical-linked covalent triazine framework (PTMR-CTF). Two micropores were established by N2 sorption the presence unpaired electrons (carbon radicals) spin...
The clogging of zeolites with carbon-containing precursors is an industrial challenge in some applications but when the deposition carbon deliberate and ‘works well’, a source material intriguing properties others. Zeolite-templated carbons (ZTCs) are often compared to activated due their shared characteristics, such as high surface area, chemical composition, thermal stability under various conditions. However, key distinction lies controllable pore size, which makes ZTCs exceptionally...
The clogging of zeolites with carbon-containing precursors is an industrial challenge in some applications but when the deposition carbon deliberate and ‘works well’, a source material intriguing properties others. Zeolite-templated carbons (ZTCs) are often compared to activated due their shared characteristics, such as high surface area, chemical composition, thermal stability under various conditions. However, key distinction lies controllable pore size, which makes ZTCs exceptionally...
Abstract Epitaxial MgB 2 thick films are grown on Al O 3 substrates at 600 °C by using the hybrid physical (HP)CVD technique. In order to obtain a high magnesium vapor pressure around substrates, we use special susceptor having cap and achieve very growth rate of 0.17 μm min –1 . Hexagonal‐shaped columnar structures observed cross‐sectional planar‐view transmission electron microscope (TEM) images. For 1.7 film, T c is be 40.5 K with J 1.5 × 10 6 A cm –2 30 K. The vortex pinning mechanism...
Abstract We report a method to create self‐cleaning, transparent surface on poly(methyl methacrylate) (PMMA) using dry etching with CF 4 plasma and subsequent hydrolysis process water immersion. During the treatment, nanoscale pillar structures were formed its aspect ratio tended increase. However, transparency was reduced due deposition accumulation of undesired capping layers, which cover structures. The used remove layers metal fluoride. As result, improves their clarity based...
A reliable method for preparing a conformal amorphous carbon (a-C) layer with thickness of 1-nm-level, is tested as possible Cu diffusion barrier next-generation ultrahigh-density semiconductor device miniaturization. polystyrene brush uniform grafted onto 4-inch SiO2 /Si wafer substrates "self-limiting" chemistry favoring such layer. UV crosslinking and subsequent carbonization transforms this polymer film into an ultrathin a-C without pinholes or hillocks. The coating nonplanar regions...
In this study, it is analyzed how sample geometry (spheres, nanofibers, or films) influences the graphitization behavior of polyacrylonitrile (PAN) molecules. The chemical bonding and changes in composition these three geometries are studied at oxidation, carbonization, stages via scanning electron microscopy (SEM), situ thermogravimetric-infrared (TGA-IR) analysis, elemental Raman spectroscopy, X-ray photoelectron spectroscopy (XPS). influence molecular alignment on investigated using...
Columnar grain boundaries are widely known to be a very effective source for flux pinning in MgB2 films. In this study, we have investigated the effect of columnar boundary at various temperatures 5, 10, 20, 30, and 35 K structured films with an average size ∼300 nm. The vortex-vortex spacing (a0) is estimated specific magnetic field, Bpeak, where Bpeak field when force density (Fp) reaches maximum. values a0/2, which largely affect interaction, much closer coherence length MgB2, than...
We have found that single-crystal films can be grown on (0001) Al 2 O 3 substrates through the golden relation of a perfect lattice-matching ratio (8:3√3) between -axis lattice constants MgB and . Selected-area electron diffraction patterns evidently indicate hexagonal film with 30° in-plane rotation respect to substrate. The critical current density at zero field is comparable depairing rapidly decreases increasing applied owing lack pinning sites, as observed for high-quality single crystals.
We report a study of the kinetics dissolution (100) and (110) single-crystal diamond plates ("D(100)" "D(110)") in thin films nickel (Ni) cobalt (Co). This occurs at metal–D(100) or metal–D(110) interface was studied presence also absence water vapor temperatures near 1000 °C. The D(100) dissolves Ni, Co, temperature range 900–1050 is too slow to measure below 900 In an argon (Ar) atmosphere (under Ar(g) flow sccm 1 atm pressure, with no present reaction chamber) any °C, metal film rapidly...
We investigated the effect of SiC doping on critical current density (Jc) in MgB2 thick films using amorphous impurity layers various thicknesses: 7, 14, 35, and 70?nm. were first deposited Al2O3(0001) substrates at room temperature by a pulsed laser deposition system, after which grown precursor hybrid physical?chemical vapor technique low growth 480??C. All samples showed high transition ~40?K irrespective thickness layer. The grain sizes slightly increased from 400 to 488?nm with...