A5026695970- Electronic and Structural Properties of Oxides
- Semiconductor materials and devices
- ZnO doping and properties
- Ga2O3 and related materials
- GaN-based semiconductor devices and materials
- Ferroelectric and Negative Capacitance Devices
- Metallurgy and Material Forming
- Magnetic and transport properties of perovskites and related materials
- Metal and Thin Film Mechanics
- Magnetic properties of thin films
- Mechanical Engineering and Vibrations Research
- Catalytic Processes in Materials Science
- Metal Forming Simulation Techniques
- Magnetism in coordination complexes
- Material Properties and Applications
- Transition Metal Oxide Nanomaterials
- Advanced Machining and Optimization Techniques
- Advancements in Battery Materials
- Nanoporous metals and alloys
- Advanced Surface Polishing Techniques
- Agricultural Engineering and Mechanization
- Metallurgical and Alloy Processes
- Electromagnetic wave absorption materials
- Advanced Thermoelectric Materials and Devices
- Gear and Bearing Dynamics Analysis
Korea Institute of Energy Research
2024-2025
Pusan National University
2017-2023
Abstract Hafnium oxides‐based ferroelectric materials are promising for applications in nonvolatile memory devices. To control the ferroelectricity of such materials, it is necessary to tune their polymorphism, interfacial features, and defect (oxygen vacancy) distribution. A strategy described enhancing properties polycrystalline hafnium zirconium oxide (HZO) ultrathin films by modifying oxygen pressure during device preparation stage, which involves thermal annealing TiN electrodes that...
Abstract Since the discovery of two-dimensional electron gas at LaAlO 3 /SrTiO interface, its intriguing physical properties have garnered significant interests for device applications. Yet, understanding response to electrical stimuli remains incomplete. Our in-situ transmission microscopy analysis a under bias reveals key insights. Inline holography visualized field-induced modulation while energy loss spectroscopy showed negligible electromigration oxygen vacancies. Instead, atom-resolved...
Understanding the ion transport mechanism in nanocomposite solid polymer electrolytes is necessary to develop next-generation electrochemical devices. We investigate role of inorganic nanoparticle on conduction and segmental dynamics cross-linked epoxy-based electrolytes, complexed with Li+F3CSO2NSO2CF3– (LiTFSI) salt Al2O3 nanowire, using dielectric relaxation spectroscopy. The addition not only increases ionic conductivity σDC by up ∼10 times but also accelerates α motion compared host...
Abstract The evaporation and crystal growth rates of ZnO are highly anisotropic fastest on the Zn-terminated (0001) polar surface. Herein, we study this behavior by direct atomic-scale observations simulations dynamic processes surface during evaporation. is accelerated dramatically at around 300 °C with spontaneous formation a few nanometer-thick quasi-liquid layer. This structurally disordered chemically Zn-deficient derived from inward diffusion Zn vacancies that stabilize controls...
Despite being a requisite for modern transparent electronics, few metals have sufficiently high infrared transmittance due to the free electron response. Here, upon alloying correlated metal SrVO3 with BaVO3, medium wavelength at of 4 μm is found be 50% higher than those Sn-doped In2O3 (ITO) and La-doped BaSnO3 (BLSO). The room temperature resistivity alloy ∼100 μΩ cm 1 order magnitude lower ITO BLSO, guaranteeing profound electromagnetic shielding effectiveness 22–31 dB 10 GHz in X-band....
The alloying behavior of crystalline SnSe<sub>1−x</sub>S<sub>x</sub> was investigated at the atomic level by combining STM experiments and DFT calculations.
Abstract Correlated transparent conductors (TCs) have attracted great attention because they can overcome the limitations of conventional TCs owing to their high visible transmittance and low sheet resistance. However, most widely studied TC 3 d 1 SrVO exhibits ultraviolet transmittance, recently investigated 4 2 SrMoO has infrared transmittance. Here, it is proposed that wide transparency range correlated arises from both correlation strength transition energy O‐2 p metal orbitals. Applying...
Individual molecular spins are promising quantum states for emerging computation technologies. The "on surface" configuration of molecules in proximity to a magnetic film allows control over the orientations and coupling between them. stacking planar could favor antiferromagnetic interlayer couplings lead pinning underlayer via exchange bias, which is extensively utilized ultrafast high-density spintronics. However, fundamental understanding bias its operating features on device has not been...
Abstract Heterointerfaces may exhibit unexpected physical properties distinct from intrinsic of component materials. In particular, metal–organic interfaces can drive unique interfacial spin moments, which are often called molecular spinterface. Here, van der Waals stacking layers lead to variations in the intra/interlayer exchange coupling resulting multiple ground states, is highly desired for multifunctional magnetic devices. this report, emergence multispinterface paramagnetic...
Abstract Polar surfaces are intrinsically unstable and thus highly reactive due to the uncompensated surface charges. The charge compensation is accompanied by various reconstructions, establishing novel functionality for their applications. present in situ atomic‐scale electron microscopy study directly shows that atomic step step‐assisted reconstruction play central roles of polar oxide surfaces. flat (LaO) + ‐terminated LaAlO 3 (001) surface, when annealed at high temperature vacuum,...
This paper develops and evaluates a mechanical machining process which involves drilling on PVS material. According to the material, two treatment experiments were conducted, one involving in wet condition or using lubricant dry with no lubricant. Drilling showed better performance terms of cutting time than condition. Otherwise, has several advantages. The influenced burr diameter size minimized temperature surface work piece. During process, smaller was noted as compared linear correlation...
In electric agricultural machine a reduction gear is needed to convert the high speed rotation motion generated by DC motor lower used vehicle. The consists of several spur gears. Spur gears are most easily visualized that transmit between two parallel shafts and easy produce. modelling simulation in important predict actual behaviour. A pair tooth action generally subjected types cyclic stress: contact stress bending stress. may not attain their maximum values at same point fatigue. These...
Polar Oxide Surfaces In article number 2303051, Jaekwang Lee, Sang Ho Oh, and co-workers discover a hitherto unknown stabilization mechanism of polar oxide surfaces using in situ atomic-scale electron microscopy combined with atomic simulation. The dynamic motion steps, activated at high temperature, converts the LaAlO3 (001) surface to nonpolar (015) vicinal via step reconstruction involving cation vacancy formation, which completely cancels electric fields along all radial directions.