A5051772867- Advanced Materials Characterization Techniques
- Microstructure and Mechanical Properties of Steels
- High Temperature Alloys and Creep
- Microstructure and mechanical properties
- Hydrogen embrittlement and corrosion behaviors in metals
- Aluminum Alloy Microstructure Properties
- High-Temperature Coating Behaviors
- Metal and Thin Film Mechanics
- Intermetallics and Advanced Alloy Properties
- Metal Alloys Wear and Properties
- ZnO doping and properties
- Aluminum Alloys Composites Properties
- GaN-based semiconductor devices and materials
- Ga2O3 and related materials
- Force Microscopy Techniques and Applications
- Advanced materials and composites
- Graphene research and applications
- Magnetic Properties and Applications
- Semiconductor materials and devices
- Diamond and Carbon-based Materials Research
- Welding Techniques and Residual Stresses
- Quantum Dots Synthesis And Properties
- Electronic and Structural Properties of Oxides
- Metallurgical Processes and Thermodynamics
- Titanium Alloys Microstructure and Properties
Northwestern University
2015-2024
Materials Science & Engineering
2011-2023
Seoul National University
2004-2020
Korea Research Institute of Standards and Science
2005-2008
Seoul National University Hospital
2008
Core/shell upconverting nanoparticles (UCNPs) of NaGdF4:Er3+,Yb3+/NaGdF4 (see figure) are shown to serve as a multimodal imaging probe that works for both background-free optical and magnetic resonance (MRI). The nonblinking nonbleaching properties UCNPs can contribute minimization possible artifacts in long-term experiments. Owing Gd3+ ions the host matrix, contrast is enhanced T1-weighted MRI.
Quantum-sized ZnS nanocrystals with quasi-spherical and rod shapes were synthesized by the aging reaction mixtures containing diethylzinc, sulfur, amine. Uniform-sized nanorods average dimension of 5 nm × 21 nm, along a small fraction nm-sized nanocrystals, adding diethylzinc to solution sulfur hexadecylamine at 125 °C, followed 300 °C. Subsequent secondary in oleylamine 60 °C for 24 h produced nearly pure nanorods. Structural characterizations showed that these had cubic zinc blende...
An effort to develop a new class of air-stable tin-based molecular semiconducting iodosalts for solar cell application.
We synthesized various hollow oxide nanoparticles from as-prepared MnO and iron nanocrystals. Heating metal nanocrystals dispersed in technical grade trioctylphosphine (TOPO) at 300 degrees C for hours yielded retaining the size shape uniformity of original The method was highly reproducible could be generalized to synthesize sizes, shapes, compositions. Control experiments revealed that impurities TOPO, especially alkylphosphonic acid, were responsible etching structures. Elemental mapping...
Ti-Nb based β-Ti alloys are a promising new class of superelastic, shape-memory, and low-modulus materials for wide range applications. A critical phase in is the ω phase, which greatly affects mechanical properties superelastic/shape-memory behaviour these materials. Zirconium, an important alloying constituent many alloys, generally regarded as suppressant, but body evidence supporting this view unconvincing includes number conflicting reports. In article, role Zr on formation clarified...
EBSD mapping was used for phase analysis of multi-phase steels. Some products austenite decomposition could be discriminated using a range grain-average functions and properties derived from the map data. In DP steels, martensite extracted ferrite matrix average band contrast or set geographic information. Bainite in TRIP steel identified with local variations orientation inside grain. As proposed method reproduced map, visual confirmation result additional analyses were possible.
We report magnetic properties of Y3Fe5O12 (YIG) films on thermally oxidized Si (100) and (Gd3Ga5O12) GGG (111) substrates. Amorphous YIG with the cation ratio Y:Fe=3.04:4.96, deposited by rf-magnetron sputtering at room temperature in pure argon atmosphere, were crystallized postannealing (600–900 °C) amorphous air 500 ppm oxygen. While postannealed substrates well textured, those randomly oriented. High-quality could be better obtained reduced (500 O2) oxygen atmosphere than since more...
Deformation and work hardening behavior of Fe-17Mn-0.02C steel containing ε-martensite within the austenite matrix have been investigated by means in situ microstructural observations x-ray diffraction analysis. During deformation, shows deformation-induced transformation → α'-martensite as well direct α'-martensite. Based on calculation changes fraction each constituent phase, we found that phase is more effective than Moreover, reverse has also observed during deformation. It originates...
Nanoparticles with high-index facets are intriguing because such can lend the structure useful functionality, including enhanced catalytic performance and wide-ranging optical tunability. Ligand-free solid-state syntheses of high index-facet nanoparticles, through an alloying-dealloying process foreign volatile metals, attractive owing to their materials generality yields. However, role atoms in stabilizing dynamic nature transformation coarsening facet regulation still poorly understood....
Structural studies on ultrathin SrRuO3∕BaTiO3∕SrRuO3 capacitors, with BaTiO3 thicknesses of between 5nm and 30nm, show well-defined interfaces ferroelectric electrode SrRuO3 layers. In these we cannot observe any extrinsic electrical effects due to either the formation an insulating interfacial passive layer or passive-layer-induced charge injection. Such high-quality result in very good fatigue endurance, even for thick capacitor.
A model in which cracks propagate by nucleation, growth, and coalescence with cavities front of the crack tip is analysed detail. The applied stress field assumed to be elastic or elastic–plastic, relaxation stresses from growth cavitation damage included analysis. spacing cavities, threshold for nucleation self-diffusion coefficients are important material parameters. results a intensity K In dependence steady-state propagation rate when I > th. distribution during transient steady states...