• Title/Summary/Keyword: perpendicular anisotropy field

Search Result 79, Processing Time 0.022 seconds

Exchange Bias Perpendicular Magnetic Anisotropy by Buffer Layer and Inserted Layer in [Pd/Co]5/FeMn Multilayer ([Pd/Co]5/FeMn 막에서의 바닥층과 삽입층에 의한 교환바이어스수직자기이방성)

  • Joo, Ho-Wan;An, Jin-Hee;Lee, Mi-Sun;Kim, Bo-Keun;Choi, Sang-Dea;Lee, Kee-Am
    • Journal of the Korean Magnetics Society
    • /
    • v.14 no.5
    • /
    • pp.192-195
    • /
    • 2004
  • Magnetic properties by exchange biased perpendicular magnetic anisotropy in [Pd(0.8 nm)/Co(0.8 nm)]$_{5}$/FeMn(15 nm) multilayers deposited by dc magnetron sputtering system are investigated. As inserted Pd layer of interface between [Pd/Co] multilayer and FeMn film, the Hex of perpendicular anisotropy was improved from 127 Oe to 145 Oe. But result of an experiment by thermal stability, the Hex of the case that an inserted layer was inserted in decreased from low 20$0^{\circ}C$ in about 5$0^{\circ}C$ more if not inserted. If Ta was a buffer layer, the experiment results along material of buffer layer, the H$_{ex}$ obtained the largest 127 Oe. And if Pd was a buffer layer, H$_{ex}$ obtained the largest 169 Oe. Also, the Hc in buffer layer of Ta and Pd obtained the largest 203 Oe and 453 Oe, respectively.

Electrode-Optic Characteristics of Fringe-field driven Twisted Nematic Mode using a Liquid Crystal with Negative Dielectric Anisotropy (유전율 이방성이 음인 액정을 이용한 fringe-field driven Twisted Nematic 모드의 전기광학 특성)

  • Song, I.S.;Shin, S.S.;Song, S.H.;Kim, H.Y.;Rhee, J.M.;Lee, S.H.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2003.07b
    • /
    • pp.1054-1057
    • /
    • 2003
  • We have studied $90^{\circ}$ twisted nematic (TN) mode driven by fringe electric field, where two polarizers are parallel each other such that the cell shows a black state before a voltage is applied. According to the studies by computer simulation for a LC with negative dielectric anisotropy, the LC twists perpendicular to the horizontal field direction of fringe electric field and the degree of tilt angle is very low, when a voltage is applied. Therefore, the new device exhibits wide viewing angle characteristic due to in-plane switching and high transmittance since the LC director aligns parallel to the polarizer axis.

  • PDF

Test of magnetic turbulence anisotropy associated with magnetic dipolarizations

  • Lee, Ji-Hee;Lee, Dae-Young;Park, Mi-Young;Kim, Kyung-Chan;Kim, Hyun-Sook
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.36 no.1
    • /
    • pp.33.2-33.2
    • /
    • 2011
  • The anisotropic nature of the magnetic turbulence associated with magnetic dipolarizations in the Earth's plasma sheet is examined. Specifically we determine the power spectral indices for the perpendicular and parallel components of the fluctuating magnetic field with respect to the background magnetic field and compare them to determine possible anisotropic features. For this study, we identify a total of 47 dipolarization events from February 2008 using the magnetic field observations by the THEMIS A, D and E satellites when they are situated closely near the neutral sheet in the near-Earth tail. For the identified events, we estimate the spectral indices for the frequency range from 1.3 mHz to 42 mHz. The results show that for many events the spectral indices are larger for fluctuations in the ${\Psi}$ direction than for those in the other two directions, where the ${\Psi}$ direction is perpendicular to the background magnetic field line and to the azimuthal direction. This implies that the dipolarization-associated turbulence of the magnetic field is often anisotropic. We discuss how this result differs from what is expected from the theory of homogeneous, anisotropic, MHD turbulence.

  • PDF

Effects of Magnetic Pole on Orientation of Bull Sperm Treated by Dithiothreitol or Heparin

  • Pham, Du Ngoc;Shinjo, Akihisa;Kurnianto, Edy
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.14 no.2
    • /
    • pp.155-162
    • /
    • 2001
  • Effect of the north (N) or south pole (S) of a magnet and dithiothreitol (DTT) or heparin sodium (H) on the orientation of bull sperm were studied. Sperm were collected from four Japanese Black bulls of Okinawa Prefectural Livestock Experimental Station were treated with various concentrations of DTT or H during the first and sixth days and were then exposed them to N or S with a magnetic field of 3,000 Gauss for 24 hours. Experimental results showed that both N and S significantly increased the perpendicular oriented percentage of bull sperm in most treatments not treated or treated with DTT or H. Anisotropy of magnetic field of bull sperm was the main cause which induced them to orient perpendicular to the magnetic direction. The results of the experiment also showed that, in most cases, the two polarities had the same effect on the orientation of bull sperm. However, in some cases, N exerted a stronger effect on the perpendicular percentage of bull sperm than S, such as with the 20 mM DTT treatment at the first and sixth days and the 100 units H treatment at the sixth day. These cases showed that the perpendicular oriented percentage of bull sperm at N was significantly higher than that of S. It was only the 100 units heparin treatment at S both at the first and sixth days that upward perpendicular orientation was higher than that at N. This might be due to the fact that protamin-DNA structure of a small number of bull sperm nuclei slightly changed because of heparin action.

Energy barrier of nanomagnet with perpendicular magnetic anisotropy

  • Song, Kyungmi;Lee, Kyung-Jin
    • Proceedings of the Korean Magnestics Society Conference
    • /
    • 2014.05a
    • /
    • pp.120-121
    • /
    • 2014
  • We investigate the field-dependence of energy barrier for various cell diameters and two type of geometry through the NEB method. We find that the energy barrier can depend strongly on the cell size when the switching is governed by the domain wall motion. Moreover we also examine the cell size dependence of energy barrier for two type of cell geometry. In the presentation, we will discuss the effect of domain wall formation and more various cell size on the energy barrier in detail.

  • PDF