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Papers by Yongsul Song

Research paper thumbnail of Effect Of Crystallization Annealing And Surface Oxidation On Electromagnetic Wave Absorption Behavior Of FeSiBNbCu Nanocrystalline Alloy

AIP Conference Proceedings, 2008

The oxidation effect of Fe73Si16B7Nb3Cu1 nanocrystalline powder on the electromagnetic (EM) wave ... more The oxidation effect of Fe73Si16B7Nb3Cu1 nanocrystalline powder on the electromagnetic (EM) wave absorption behavior has been investigated. The oxidation did not improve the absorption characteristics of the nanocrystalline soft magnetic material. The pulverization and milling lowered the optimum crystallization temperature of the nanocrystalline material because of the accumulated internal energy due to impact during fragmentation and powder thinning.

Research paper thumbnail of Effect of crystallization condition on the Microwave properties of Fe-based amorphous alloy flakes and polymer composites

Journal of Physics: Conference Series, 2009

ABSTRACT The electromagnetic (EM) wave absorption properties with a variation of crystallization ... more ABSTRACT The electromagnetic (EM) wave absorption properties with a variation of crystallization temperature have been investigated in a sheet-type absorber made of the amorphous Fe73Si16B7Nb3Cu1Finemet powder. With the variation of the annealing temperature, the magnetic and dielectric properties of the crystallized Fe-based absorber with a nano-structure were changed. The complex permittivity increased with increasing the annealing temperature, whereas the complex permeability was maximized after annealing at 530°C for 1 hour. The absolute value of the reflection parameter, |S11|, increased with increasing annealing temperature of the nanocrystalline alloy powder. On the contrary, the transmission one, |S21|, showed the highest value after annealing at 530°C for 1 hour, which is regarded as the optimum temperature for the improvement of EM wave absorption properties.

Research paper thumbnail of Synthesis of Ag nanoparticles using an electrolysis method and application to inkjet printing

Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2011

This paper reports a new mass-production method for synthesizing Ag nano-particles using electrol... more This paper reports a new mass-production method for synthesizing Ag nano-particles using electrolysis. In this method, Ag ions were directly and continuously extracted from 99 wt% Ag metal electrodes and a reduction agent reduced them to Ag nano-particles. By changing the applied voltage and electrolyte temperature, the average size of the synthesized Ag particles was shown to vary in the range of 10-80 nm. These particles were tested for the possibility of micropatterning of the electrode on a polyimide substrate. As a result, patterns as fine as 50-100 m with a relatively low resistivity of 6.5 cm were successfully obtained.

Research paper thumbnail of A Study on Annealing of Fe-Si-B-Ni Amorphous Alloy

Korean Journal of Materials Research, 2003

Research paper thumbnail of Effect Of Crystallization Annealing And Surface Oxidation On Electromagnetic Wave Absorption Behavior Of FeSiBNbCu Nanocrystalline Alloy

AIP Conference Proceedings, 2008

The oxidation effect of Fe73Si16B7Nb3Cu1 nanocrystalline powder on the electromagnetic (EM) wave ... more The oxidation effect of Fe73Si16B7Nb3Cu1 nanocrystalline powder on the electromagnetic (EM) wave absorption behavior has been investigated. The oxidation did not improve the absorption characteristics of the nanocrystalline soft magnetic material. The pulverization and milling lowered the optimum crystallization temperature of the nanocrystalline material because of the accumulated internal energy due to impact during fragmentation and powder thinning.

Research paper thumbnail of Effect of crystallization condition on the Microwave properties of Fe-based amorphous alloy flakes and polymer composites

Journal of Physics: Conference Series, 2009

ABSTRACT The electromagnetic (EM) wave absorption properties with a variation of crystallization ... more ABSTRACT The electromagnetic (EM) wave absorption properties with a variation of crystallization temperature have been investigated in a sheet-type absorber made of the amorphous Fe73Si16B7Nb3Cu1Finemet powder. With the variation of the annealing temperature, the magnetic and dielectric properties of the crystallized Fe-based absorber with a nano-structure were changed. The complex permittivity increased with increasing the annealing temperature, whereas the complex permeability was maximized after annealing at 530°C for 1 hour. The absolute value of the reflection parameter, |S11|, increased with increasing annealing temperature of the nanocrystalline alloy powder. On the contrary, the transmission one, |S21|, showed the highest value after annealing at 530°C for 1 hour, which is regarded as the optimum temperature for the improvement of EM wave absorption properties.

Research paper thumbnail of Synthesis of Ag nanoparticles using an electrolysis method and application to inkjet printing

Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2011

This paper reports a new mass-production method for synthesizing Ag nano-particles using electrol... more This paper reports a new mass-production method for synthesizing Ag nano-particles using electrolysis. In this method, Ag ions were directly and continuously extracted from 99 wt% Ag metal electrodes and a reduction agent reduced them to Ag nano-particles. By changing the applied voltage and electrolyte temperature, the average size of the synthesized Ag particles was shown to vary in the range of 10-80 nm. These particles were tested for the possibility of micropatterning of the electrode on a polyimide substrate. As a result, patterns as fine as 50-100 m with a relatively low resistivity of 6.5 cm were successfully obtained.

Research paper thumbnail of A Study on Annealing of Fe-Si-B-Ni Amorphous Alloy

Korean Journal of Materials Research, 2003

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