• DocumentCode
    1045629
  • Title

    Anisotropy line broadening and related problems in polycrystalline NiFe2O4

  • Author

    Krishnan, Ramanathan

  • Author_Institution
    Centre National de Recherche Scientifique, 92 Bellevue, France.
  • Volume
    7
  • Issue
    1
  • fYear
    1971
  • fDate
    3/1/1971 12:00:00 AM
  • Firstpage
    202
  • Lastpage
    204
  • Abstract
    Ferrimagnetic resonance line width in slowly cooled and quenched samples of polycrystalline NiFe2O4has been measured in the X band in the range 4.2 to 373°K. Results confirm that the porosity contribution to the line width is best described by the relation \\Delta H_{p} = [K.4 \\pi M/(V/\\upsilon ) + 1)] with K = 1 , though this overestimates \\Delta H_{p} in certain cases. The anisotropy contribution to the line width according to Schlömann is \\Delta H_{a} = C \\cdot H_{a^{1}}/4 \\pi M , with C \\cong 2.07 when H_{a}\\ll 4 M. But our results show that C depends upon the sign of K1. For K_{1} < 0, C = 2.5 and for K_{1} > 0 , C \\cong 1.2 in range 180 Oe \\leq K/M \\leq 360 Oe. For very low values of K_{1}/M , C deviates very much from 2, and particularly so for K_{1} < 0 . The effect of K2is shown to be negligible. Hence the result is interpreted in terms of an effective anisotropy field which takes into account the magnetoelastic energy as well.
  • Keywords
    Ferromagnetic resonance; Magnetic anisotropy; Nickel ferrites; Anisotropic magnetoresistance; Crystalline materials; Ferrimagnetic materials; Ferrites; Magnetic anisotropy; Magnetic field induced strain; Magnetic materials; Magnetic resonance; Perpendicular magnetic anisotropy; Saturation magnetization;
  • fLanguage
    English
  • Journal_Title
    Magnetics, IEEE Transactions on
  • Publisher
    ieee
  • ISSN
    0018-9464
  • Type

    jour

  • DOI
    10.1109/TMAG.1971.1067008
  • Filename
    1067008