Seon-Keun Choi
Hanyang University · 材料科学
研究室紹介
Professor Seon-Keun Choi's research lab specializes in the synthesis and characterization of advanced magnetic nanomaterials, with a focus on ferrite-based composites and core/shell-structured nanoparticles. The lab employs innovative fabrication techniques such as the self-propagating combustion method and hydrogen reduction to develop materials with tailored magnetic properties, including enhanced saturation magnetization and high-frequency stability. Their work also extends to the fundamental study of magnetic thin films and dusty plasma systems, using advanced measurement techniques like coplanar waveguide methods and planar electric probes to investigate frequency-dependent permeability and particle-plasma interactions. The lab's interdisciplinary approach bridges materials science, magnetism, and plasma physics, aiming to advance applications in high-frequency electronics and energy-related technologies.
Research Overview
Research Output Trend
Figures are computed from collected data and may differ slightly.
Selected Papers
5Abstract Ba‐hexaferrite and Ni 0.5 Zn 0.5 ferrite nano composites have been successfully fabricated by a self‐propagating combustion method. Transmission electron microscopy and X‐ray diffractometer analysis showed that two ferrite phases were homogeneously distributed and the measured grain size of them around 20nm. The saturation magnetizations of the composites were revealed to be increased compared with the theoretical values. These increments of the saturation magnetization values could be
Ferromagnetic nanoparticles with a core/shell structure were fabricated by a self-propagating combustion method and subsequent hydrogen reduction process. Before the reduction process, synthesized particles were Fe oxide phases. Transmission electron micrographs confirmed that the nanoparticles were composed of α-Fe core and Fe–Al oxide shell after the reduction process. The saturation magnetization of the nanoparticles was measured about 180 emu/g and the permeability kept constant value of abo
Abstract A broadband coplanar waveguide method, recognized as a simple and effective broadband permeability measurement tool, was used to measure the frequency dependent permeability of various magnetic thin films. It was revealed that measured permeability was strongly dependent on the dimension of the films and the geometry of the waveguide. This dependency was proven to result from the confinement of magnetic fields in the films by LLG equation. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, W
We investigated charged dust and its effect on RF plasma by using a planar electric probe in a large-scale device. In background plasmas, the particle density is 108 to 109 cm−3 and the electron temperature is 2 to 4 eV. When dust is contained in plasma, it is negatively charged by electrons attached to the dust. The charged dust density and the charge were calculated by comparing dusty helium plasma to pure helium plasma. Depending on the increase in the amount of dust, the charged dust density