• Title/Summary/Keyword: Perpendicular anisotropy

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Magnetic Resonance Neurography Using the Anisotropy of Diffusion Coefficients (확산계수의 이방성을 이용한 자기공명 신경망조영술)

  • Lee, Su-Yeol;Mun, Chi-Ung;Im, Tae-Hwan
    • Journal of Biomedical Engineering Research
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    • v.15 no.4
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    • pp.401-406
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    • 1994
  • A magnetic resonance neurography technique for exclusive imaging of nerve networks is proposed. In the proposed technique, the anisotropy of diffusion coefficients of the molecules inside nerve cells was utilized to effectively suppress the magnetic resonance signal radiating from ones other than nerve tissues. Two images were obtained with diffusionweighting magnetic field gradients applied in the parallel and perpendicular directions with respect to the nerve orientation. One image was then subtract- ted from the other to form the neurogram. Experimentally obtained neurograms of the squld are presented.

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The Effects Influenced on the Magnetic Properties by Depositing Fe-C in the Bottom Extremity of the Co-Fe Electrodeposited Anodic Oxidized Films (Co-Fe 석출 양극산화피막의 초기석출부에 석출한 Fe-C가 자기특성에 미치는 영향)

  • Kang, H.W.
    • Proceedings of the KIEE Conference
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    • 1994.07b
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    • pp.1295-1297
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    • 1994
  • At 34 at% Co-Fe, the aluminum anodic oxidized (alumite) films of particle diameter $150{\AA}$ have large perpendicular anisotropy energy and high coercive force. However, for the samples of particle diameter larger than $450{\AA}$, the bottom of each particle forms abnormal part called branch-shaped different from that of particle diameter $150{\AA}$. In this case the magnetic anisotropy energy Ku was about zero at the compositions of 45 and 75 at% Co. Furthermore, at tile compositions from 50 to 70 at% Co, the values of Ku became negative value. We confirmed that Fe-C deposited the bottom of particle orients very strongly and it has a large influence upon the magnetic anisotropy energy.

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Simulations of Ferromagnetic Resonance Spectra Excited in Magnetic Bilayers (이층 자성막에서 여기되는 강자성 공명신호의 모의실험)

  • 김약연;한기평;유성초
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.16 no.3
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    • pp.238-246
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    • 2003
  • We have performed the simulation of ferromagnetic resonance spectra on the exchange coupled bilayer thin films at perpendicular configuration. Variables considered in spectrum calculation were the interfacial exchange constants per unit area, the layer thickness, and the surface anisotropy constants. In case of antiferromagnetic coupling, variation of exchange constant gave a great effect to the absorption spectra of the low and the high magnetization layer. Variation of thickness in low magnetization layer did nt nearly influenced the resonated field of the high magnetization layer. Also, the increase of negative surface anisotropy increased the resonance field of the low and the high magnetization layer.