• Title/Summary/Keyword: Soft magnetics

Search Result 290, Processing Time 0.019 seconds

Soft Magnetic Property Analysis of Nanocrystalline Fe-Al-O Film with the Change of Microstructure (나노 결정립 Fe-Al-O 산화막의 미세구조 변화에 따른 연자기적 특성 분석)

  • Lee, Young-Woo;Park, Bum-Chan;Kim, Chong-Oh;Moon, Ji-Hyun;Choi, Yong-Dae
    • Journal of the Korean Magnetics Society
    • /
    • v.14 no.2
    • /
    • pp.59-64
    • /
    • 2004
  • We investigated the soft magnetic properties of nanocrystalline Fe-Al-O film as etching the oxide film with ion beam etching method. It is thought that the grain size of Fe-Al-O film increases as the thickness decreases. The coercivity and squareness increase with decreasing thickness. The surface curvature of Am images increases when the etching experiment proceeds. This phenomena could be due to the grain growth which occurs during sputtering. This grain growth could be assisted by the the plasma energy during sputtering. Therefore proper thickness should be searched to acquire the good soft magnetic properties for the nanocrystalline film material. Good soft magnetic properties of Fe-Al-O film was acquired at the thickness of more than 900 nm.

Hysteresis Loops, Critical Fields and Energy Products for Exchange-spring Hard/soft/hard Trilayers

  • Chen, B.Z.;Yan, S.;Ju, Y.Z.;Zhao, G.P.;Zhang, X.C.;Yue, M.;Xia, J.
    • Journal of Magnetics
    • /
    • v.20 no.1
    • /
    • pp.31-39
    • /
    • 2015
  • Macroscopic hysteresis loops and microscopic magnetic moment distributions have been determined by a three-dimensional (3D) model for exchange-coupled Sm-Co/${\alpha}-Fe$/Sm-Co trilayers with in-plane collinear easy axes. These results are carefully compared with the popular one-dimensional (1D) micromagnetic models and recent experimental data. It is found that the results obtained from the two methods match very well, especially for the remanence and coercivity, justifying the calculations. Both nucleation and coercive fields decrease monotonically as the soft layer thickness $L^s$ increases while the largest maximum energy product (roughly 50 MGOe) occurs when the thicknesses of hard and soft layers are 5 nm and 15 nm, respectively. Moreover, the calculated angular distributions in the thickness direction for the magnetic moments are similar. Nevertheless, the calculated nucleation and pinning fields as well as the energy products by 3D OOMMF are systematically smaller than those given by the 1D model, due mainly to the stray fields at the corners of the films. These demagnetization fields help the magnetic moments at the corners to deviate from the previous saturation state and facilitate the nucleation. Such an effect enhances as $L^s$ increases. When the thicknesses of hard and soft layers are 10 nm and 20 nm, respectively, the pinning field difference is as large as 30%, while the nucleation fields have opposite signs.

Magnetic Sensors and Actuators

  • Pasquale, M.
    • Journal of Magnetics
    • /
    • v.8 no.1
    • /
    • pp.60-69
    • /
    • 2003
  • A review of mechanical sensing techniques based on magnetic methods is presented, with special reference to magnetoelastic strain gauges and force sensors. A novel strain sensor based on soft amorphous ribbons is described. Other types of magnetic sensors, for the measurement of torque and displacement are briefly discussed. An overview of magnetic actuators based on giant magnetostrictive materials, with some practical examples, is presented. Recent advances in the development and application of magnetic shape memory materials are discussed, together with the analysis of recent studies for the description of magnetic shape memory phenomena.

COLLINEARITY AND SPIN FREEZING

  • Vincze, I.;Kemeny, T.
    • Journal of the Korean Magnetics Society
    • /
    • v.5 no.5
    • /
    • pp.343-350
    • /
    • 1995
  • An overview will be given on recent Mossbauer and magnetization investigation of the applied field dependence of the magnetic properties of typical systems without strong magnetic anisotropy and showing the absence of magnetic saturation in high fields (including iron-rich spin glass (amorphous $Fe_{93}Zr_{7}$, soft ferromagnets (amorphous $Fe_{88}Zr_{12}$, $Fe_{70}Ni_{20}Zr_{10}$ and $Fe_{88}B_{12}$) and pure Fe). The results emphasize that shape anisotropy due to surface irregularities causes misalignment between the magnetization and the applied field in the otherwise collinear magnetic structure.

  • PDF