• Journal of the Korean institute of surface engineering
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• v.31 no.4
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• pp.199-208
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• 1998

자벽고착 개념에 기초를 둔 새로운 조화센서는 다음과 같이 설명되어진다. 2단계 열처리된 Co계 비전질 percursor은 특이한 signal을 유발시키는데 이는 자속의 단계적인 변화를 나타내는 hystresisloop에 기인한다. 자장하에서의 1단계 열처리는 M-H loop에서 일축유도 자기이방성을 발생시킨다. 2단계 무자장하의 열처리는 고착된 자벽의 stepped hystresis의 특성을 나타내는데 이로인해 유용한 marker로서의 특징을 가지게 된다. 열처리동안 비정질재료의 표면과 내부에서 상당량의 산화와 결정화 과정을 거치는 것이 관찰되었다. 이오인한 표면 자벽 고착 모델의 제안은 자벽의 고착이 비정질부분과 semi-hard Co 층간의 접합면에서 가장 효과적으로 얻어지다는 것으로써 확신되어진다. 또한 자벽 고착 자장과 결정화된 Co층의 두께간의 상당한 연관성도 관찰되었다.

• Journal of the Korean Magnetics Society
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• v.15 no.6
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• pp.303-306
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• 2005

Effect of a ferromagnetic layer thickness on a narrow domain wall width is investigated. It is found that the narrow domain wall is formed in ferromagnetic/nonmagnetic/ferromagnetic multi layer structure with a loc at interlayer exchange coupling, and that the width of the narrow domain wall is affected by the ferromagnetic layer thickness. We performed micromagnetics simulations for the $Fe_1/Cr/Fe_2$ system with the local interlayer exchange coupling, with fixed thickness (20-nm) of $Fe_2$ layer and various $Fe_1$ layer thickness (1, 2, 4, and 6 nm). Consequently, we confirmed that the thinner the $Fe_1$ layer thickness, the thinner the width of the domain wall is formed, because of the surface energy nature of the interlayer exchange coupling.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.10
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• pp.1849-1860
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• 1994

Domain wall dynamics in thin film of amorphous Rare Earth-Transistion Metal alloys were investigated using numerical integration of the Landau-Lifshitz-Gilbert equation. The thin film was divided into a two-dimensional square lattice ($30\times30$) of dipoles. Nearest-neighbor exchange interaction magnetic anisotropy, applied magnetic field, and demagnetiing field of interacting anisotropy, applied magnetic field, and demagnetizing field of interacting dipoles were considered. It was assumed that the film had perfect uniaxial anisotropy in the perpendicular direction and the magnetization reversal existed in the film. The time of domain wall creation and the thickness of the wall were investigated. Also the motion of domain walls under an applied field was considered. Simulation results showed that the time of domain wall creation was decreased significantly and the average velocity of domain wall was increased somewhat when the demagnetizing field was considered.

• Journal of the Korean Magnetics Society
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• v.15 no.4
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• pp.221-225
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• 2005

Formation of a narrow magnetic domain wall is demonstrated by micromagnetics simulations. It is found that the domain wall width can be shrunk in a local exchange coupled system. The local exchange coupled system means that only a part of a ferromagnetic layer has an exchange coupling with another ferromagnetic layer. The system can be considered as two parts in the lateral dimensions: one is an exchange coupled region and another is a free region. Since the two regions have quite different local switching fields, the domain wall will be formed at the interface between the two regions at moderate field ranges.

• Journal of the Korean Magnetics Society
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• v.21 no.6
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• pp.193-197
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• 2011

The thickness dependence of the magnetic switching volumes in electrodeposited CoPt films was investigated from the magnetization reversal and the magnetic interaction behavior. As the sample thickness is increased, the field difference between the wall pinning field ($H_{DW}$) and the nucleation field ($H_N$) as well as the absolute value of ${\Delta}$area are increased. Therefore, the decrement tendency of the switching diameter with increasing sample thickness can be well explained by the domain wall motion controlled by the domain wall pinning and the strength of dipolar interaction.

• Journal of the Korean Magnetics Society
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• v.20 no.1
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• pp.1-7
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• 2010

We investigate the spin dynamics of the magnetic domain wall using the magnetic noise in the magnetic nanowire structure by employing micromagnetic simulations. Magnetic noise due to the thermal fluctuations in ferromagnetic materials is related to magnetic susceptibility and resonance frequency, which are important physical quantities in the study of the spin dynamics. In this study, we present the magnetic noise of the single domain without magnetic domain wall, and with the magnetic domain wall between two magnetic domains in ferromagnetic nanowires. It is confirmed that the Kittel equation with simple ellipsoid model with demagnetizing factor well describe the resonance frequency due to magnetic noise of the single domain. Besides, we find that there is a distinguishable additional resonance frequency, when a magnetic domain wall exists. It is verified that the additional resonance frequency is originated from the magnetic domain wall, and it is lower than one of the single domain. It implies that the spins inside the domain wall have a different effective field.

• Proceedings of the Korean Magnestics Society Conference
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• 2004.12a
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• pp.204-205
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• 2004

• Proceedings of the Korean Magnestics Society Conference
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• 1993.03a
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• pp.102-103
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• 1993

• Proceedings of the Korean Magnestics Society Conference
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• 2001.04a
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• pp.18-19
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• 2001

• Proceedings of the Korean Magnestics Society Conference
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• 2005.12a
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• pp.160-161
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• 2005