A5062563730- Diamond and Carbon-based Materials Research
- Graphene research and applications
- Carbon Nanotubes in Composites
- Metal and Thin Film Mechanics
- High-pressure geophysics and materials
- Boron and Carbon Nanomaterials Research
- MXene and MAX Phase Materials
- Mechanical and Optical Resonators
- Force Microscopy Techniques and Applications
- 2D Materials and Applications
- Electronic and Structural Properties of Oxides
- Graphite, nuclear technology, radiation studies
- Advanced Surface Polishing Techniques
- Advanced materials and composites
- Semiconductor materials and devices
- Tunneling and Rock Mechanics
- Ion-surface interactions and analysis
- Graphene and Nanomaterials Applications
- Retirement, Disability, and Employment
- Ga2O3 and related materials
- Advancements in Battery Materials
- Chemical and Physical Properties of Materials
- Fullerene Chemistry and Applications
- Laser-Ablation Synthesis of Nanoparticles
- Phase Equilibria and Thermodynamics
Korea Institute of Science and Technology
2008-2023
Heriot-Watt University
2004-2006
Korean Association Of Science and Technology Studies
1996
Stacked AA graphite has been synthesized using a high-density dc plasma in hydrogen-methane mixtures. Graphene layers have grown epitaxially with 2-1 registration between the graphitic edges and (111) surface of diamond. In addition, new crystal structure containing AA′ graphene layers, where alternate planes are translated by half hexagon width, is formed 1-1 registry. The resulting interplanar distances at interface range from 2.20Å for to 4.40Å measured directly high-resolution...
Abstract Two-dimensional gallium nitride (2D GaN) with a large direct bandgap of ~5.3 eV, high melting temperature ~2500 °C, and Young’s modulus ~20 GPa developed for miniaturized interactive electronic gadgets can function at thermal mechanical loading conditions. Having various electronic, optoelectronic, spintronic, energy storage devices sensors in perspective the robust nature 2D GaN, it is highly imperative to explore new pathways its synthesis. Moreover, free-standing sheets will be...
Over the history of carbon, it is generally acknowledged that Bernal AB stacking sp2 carbon layers unique crystalline form graphite. The universal graphite structure synthesized at 2,600~3,000 °C and exhibits a micro-polycrystalline feature. In this paper, we provide evidence for metastable with an AA' structure. non-Bernal allotrope by thermal- plasma-treatment graphene nanopowders ~1,500 °C. formation bilayer nuclei facilitates preferred texture growth results in single-crystal nanoribbons...
Raman spectra of single-wall carbon nanotubes (SWNTs) exhibit a unique radial breathing mode (RBM) band (∼100–300 cm–1) and G– peak (∼1570 cm–1), along with D (∼1350 cm–1). We show that the typical signals for SWNTs are signature their helical structure determined using density functional theory simulation structural analysis hydrogenated dehydrogenated SWNT samples. demonstrate at ∼1570 cm–1 is to opened tubular graphene structures ∼2 nm diameter. also ∼1350 originated from edge defects...
Abstract In this paper, we demonstrate the seeded growth of graphene under a plasma chemical vapor deposition condition. First, fabricate nanopowders (~5 nm) by ball-milling commercial multi-wall carbon nanotubes. The nanoparticles were subsequently subject to direct current generated in 100 Torr 10%CH 4 - 90%H 2 gas mixture. enlarged, over one hour, nuclei sheets larger than hundred nm area. Characterization electron and X-ray diffraction, high-resolution transmission microscopy images...
The low-frequency Raman signals of single-wall carbon nanotubes (SWNTs), appearing in the range 100-300 cm-1, have been interpreted as radial-breathing mode (RBM) comprising pure radial Eigenvectors. Here, we report that most and intermediate-frequency SWNTs are radial-tangential modes (RTMs) coexisting tangential Eigenvectors, while only first peak at side is RBM. Density functional theory simulation for ~ 2 nm diameter shows dozens RTMs exhibit following RBM (~ 150 cm-1) up to G-mode 1592...
Herein a method is proposed for engineering the electronic properties of diamond <italic>via</italic> surface hybridization with graphene.
Anisotropic metal nanostructures (e.g., Au–Ag, Au–Cu) are emerging for biomedical and catalytic applications in recent years. Herein, we report a modified synthesis of Cu–Au tripod nanocrystals through the controlled nucleation growth process with judicious purification photothermal based anticancer therapy. The distribution was analyzed by STEM-EDX mapping, indicating formation alloy nanocrystals. Theoretical calculations showed possible structures, that is, Cu3Au, Cu–Au, CuAu3 confirmed...
Evidence is presented in this paper that certain single-wall carbon nanotubes are not seamless tubes, but rather adopt a graphene helix resulting from the spiral growth of nano-graphene ribbon. The residual traces helices confirmed by high-resolution transmission electron microscopy and atomic force microscopy. analysis also shows tubular material may exhibit unique armchair structure chirality necessary condition for nanotubes. description helical nanomaterials generalized using plane...
One of the unsolved fundamental issues graphene is establishing an appropriate way to discern layers structures. We report a simple methodology analyze structures using Raman signals in range ∼100 ∼500 cm–1 comprising clear 118 or 175 peaks. demonstrate that low-energy on spectra plasma-seeded grown sheets originated from nanocurvature (c) mono- (175 and 325–500 signals) (c ≈ 1 nm) bilayer (118 peak) 2 with simulations, based radial mode (RM) Eigen vectors. Our RM model provides standard...
We elucidate the doping mechanism of suitable elements into borophene with first-principles density functional theory calculation. During nitrogen (N), sp
The structure of multi-wall carbon nanotubes has been attributed previously to disordered stacking the graphene planes.
Hexagonal boron nitride ( h -BN) has been generally interpreted as having an AA stacking sequence. Evidence is presented in this article indicating that typical commercial -BN platelets (∼10–500 nm thickness) exhibit stacks of parallel nanosheets (∼10 predominantly the AB The AB-stacked nanosheet occurs a metastable phase resulting from preferred texture and lateral growth armchair (110) planes. It appears independent or unit for platelets. analysis supported by simulation thin films (2–20...