• Title/Summary/Keyword: magnetic structure

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Electronic and Magnetic Structure Calculations of Cubane-type Co4 Magnetic Molecule (Cubane 구조를 가진 Co4 분자자성체의 전자구조 및 자기구조계산)

  • Park, Key Taeck
    • Journal of the Korean Magnetics Society
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    • v.27 no.4
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    • pp.140-144
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    • 2017

  • We have studied electronic and magnetic structure of cubane-type Co magnetic molecule using density functional method. The calculated density of states show $Co^{+2}$ ionic state and high-spin state because of large exchange interaction between inside Co 3d electrons. The exchange interaction J between Co atoms depends Co-O-Co angle. The calculated J is ferromagnetic with right angles. On the other hand J is antiferromagnetic with large angles since super-exchange interactions between $Co^{+2}$ atoms. It induces that Co cubane has a antiferromagnetic spin structure of AFM1 = [${\uparrow}{\uparrow}{\downarrow}{\downarrow}$]

  • https://doi.org/10.4283/JKMS.2017.27.4.140 인용 PDF KSCI

Analysis of an Interior Permanent-Magnet Machines with an Axial Overhang Structure based on Lumped Magnetic Circuit Model

  • Seo, Jangho;Seo, Jung-Moo
    • Journal of Magnetics
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    • v.21 no.1
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    • pp.94-101
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    • 2016

  • This paper shows a new magnetic field analysis of an interior permanent magnet (IPM) machines with an axial overhang structure wherein the rotor axial length exceeds that of the stator. The rotor overhang used to increase torque density of the radial flux machine is difficult to analyze because of extra consideration of axial direction, and thus it is general for machine designer to take 3-D finite element analysis (FEA) capable of considering both radial and axial complicated geometry in the machine. However, it requires too much computing time for preliminary design especially for optimization process. Therefore, in this paper a 2-D analytic method using a lumped magnetic circuit model (LMCM) is proposed to overcome the problem. For the analysis of overhang effect, the magnetic circuit is separated and solved from overhang and non-overhang regions respectively. For the validation of proposed concept, 3-D finite element analysis (FEA) is performed. From the analysis results, it is shown that our new proposed method presents good performance in terms of calculating electromotive force (EMF) and torque within a short time. Therefore, the proposed model can be useful in design of IPM with an overhang structure.

  • https://doi.org/10.4283/JMAG.2016.21.1.094 인용 PDF KSCI