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Exchange Anisotropy of Polycrystalline Ferromagnetic/Antiferromagnetic Bilayers

  • Published : 2002.09.01

Abstract

The role of magnetic anisotropy of the antiferromagnetic layer on the magnetization process of exchange coupled polycrystalline ferromagnetidantiferromagnetic bilayers is discussed. In order to elucidate the magnetic torque response of Ni-Fe/Mn-Ir bilayers, the single spin ensemble model is newly introduced, taking into account the two-dimensionally random distribution of the magnetic anisotropy axes of the antiferromagnetic grains. The mechanism of the reversible inducement of the exchange anisotropy along desirable directions by field cooling procedure is successfully explained with the new model. Unidirectional anisotropy constant, J$k$, of polycrystalline Ni-Fe/Mn-Ir and Co-Fe/Mn-Ir bilayers is investigated as functions of the chemical composition of both the ferromagnetic layer and the antiferromagnetic layer. The effects of microstructure and surface modification of the antiferromagnetic layer on JK are also discussed. As a notable result, an extra large value of J$k$, which exceeds 0.5 erg/cm$^2$, is obtained for $Co_{70}Fe_{30}Mn_{75}Ir_{25}$ bilayer with the ultra-thin (50${\AA}$∼100${\AA}$) Mn-Ir layer. The exchange anisotropy of $Co_{70}Fe_{30}$ 40 ${\AA}/Mn_{75}Ir_{25}$ 100 ${\AA}$ bilayer is stable for thermal annealing up to $400{^{\circ}C}$, which is sufficiently high for the application of spin valve magnetoresistive devices.

Keywords

References

  1. J. Magn. Magn. Mater. v.192 See, e. g.;J. Nogues;I. K. Schuller https://doi.org/10.1016/S0304-8853(98)00266-2
  2. Phys. Rev. v.102;105 w. H. Meiklejohn;C. P. Bean https://doi.org/10.1103/PhysRev.102.1413
  3. J. Appl. Phys. v.33 W. H. Meiklejohn https://doi.org/10.1063/1.1728716
  4. J. Appl. Phys. v.62 D. Mauri;H. C. Siegmann;P. S. Bagus;E. Kay https://doi.org/10.1063/1.339367
  5. Phys. rev. B. v.59 M. D. Stiles;R. D. McMichael https://doi.org/10.1103/PhysRevB.59.3722
  6. Phys. Rev. B. v.61 H. Xi;R. M. White https://doi.org/10.1103/PhysRevB.61.80
  7. Digests of the INTERMAG'96 Coference V. S. Speriosu;B. A. Gurney;D. R. Wilhoit;L. B. Brown
  8. IEEE Trans. Magn. v.32 H. Berg;W. Clemens;G. Gieres;G. Rupp;W. Schelter;M. Vieth https://doi.org/10.1109/20.539099
  9. IEEE Trans. Magn. v.31 K. Okuyama;T. Shimatsu;S. Kuji;M. Takahashi https://doi.org/10.1109/20.489789
  10. Vacuum v.59 M. takahashi;M. Tsunoda;H. Shoji https://doi.org/10.1016/S0042-207X(00)00352-3
  11. J. Appl. Phys. v.89 K. Yagami;M. Tsunoda;M. Takahashi https://doi.org/10.1063/1.1357146
  12. J. Appl. Cryst. v.6 A. Segmuller;A. E. Blackeslee https://doi.org/10.1107/S0021889873007995
  13. Phys. rev. Lett. v.44 I. K. Schuller https://doi.org/10.1103/PhysRevLett.44.1597
  14. J. Appl. Phys. v.87 M. Tsunoda;Y. Tsuchiya;T. Hashimoto;M. Takahashi https://doi.org/10.1063/1.373081
  15. J. Appl. Phys. v.87 K. Yagami;M. Tsunoda;M. Takahashi https://doi.org/10.1063/1.373206
  16. J. Appl. Phys. v.87 M. Tsunoda;M. Takahashi https://doi.org/10.1063/1.373214
  17. J. Appl. Phys. v.87 M. Tsunoda;M. Takahashi https://doi.org/10.1063/1.372723
  18. J. Magn. Soc. Jpn. v.25 M. Tsunoda;T. Hashimoto;M. Konoto;M. Takahashi https://doi.org/10.3379/jmsjmag.25.827
  19. J. Magn. Magn. Mater. v.239 M. Tsunoda;M. Takahashi https://doi.org/10.1016/S0304-8853(01)00574-1
  20. J. appl. Phys. v.43 E. Fulcomer;S. H. Charap https://doi.org/10.1063/1.1660894
  21. IEEE Trans. Magn. v.35 m. Mao;S. Funada;C.-Y. Hung;T. Schneider;M. Miller;H.-C. Tong;C. Qian;L. Miloslavsky https://doi.org/10.1109/20.800706
  22. J. Appl. Phys. v.85 J. Driel;R. Coehoorn;K.-M. H. Lenssen;A. E. T. Kuiper;F. R. Boer https://doi.org/10.1063/1.369881
  23. J. Appl. Phys. v.87 M. Pakala;Y. Huai;G. Anderson;L. Miloslavsky https://doi.org/10.1063/1.372800
  24. J. Appl. Phys. v.87 G. Anderson;Y. Huai;L. Miloslavsky https://doi.org/10.1063/1.372907
  25. IEEE Trans. Magn. v.35 K. Yagami;M. Tsunoda;S. Sugano;M. Takahashi https://doi.org/10.1109/20.800708
  26. J. Appl. Phys. v.36 K. Yagami;M. Tsunoda;S. Sugano;M. Takahashi
  27. Jpn. J. appl. Phys. v.35 K. Hoshino;R. Nakatani;H. Hoshiya;Y. Sugita;S. Tsunashima https://doi.org/10.1143/JJAP.35.607
  28. J. Appl. Phys. v.81 H. N. Fuke;K. Saito;Y. Kamiguchi;H. Iwasaki;M. Sahashi https://doi.org/10.1063/1.364920
  29. J. Appl. Phys. v.83 A. J. Devasahayam;P. J. Sides;M. H. Kryder https://doi.org/10.1063/1.367550
  30. IEEE Trans. Magn. v.33 K. Uneyama;M. Tsunoda;M. Takahashi https://doi.org/10.1109/20.619538
  31. IEEE Trans. Magn. v.33 M. Tsunoda;M. Konoto;K. Uneyama;M. Takahashi https://doi.org/10.1109/20.619539
  32. J. Appl. Phys. v.85 M. Tsunoda;K. Uneyama;T. Suzuki;K. Yagami;M. Takahashi https://doi.org/10.1063/1.369142
  33. J. Magn. Magn. Mat. v.209 M. Takahashi;M. Tsunoda;K. Uneyama https://doi.org/10.1016/S0304-8853(99)00647-2
  34. Element of X-ray diffraction(2nd edition) B. D. Cullity
  35. J. Appl. Phys. v.80 K. Nishioka;C. Hou;H. Fujiwara;R. D. Metzger https://doi.org/10.1063/1.363433
  36. J. Appl. Phys. v.83 K. Nishioka;S. Shigematsu;T. Imagawa;S. Narishige https://doi.org/10.1063/1.367090
  37. J. Magn. Magn. Mat. v.171 M. Tsunoda;Y. Tsuchiya;M. Konoto;M. Takahashi https://doi.org/10.1016/S0304-8853(97)00054-1
  38. J. Appl. Phys. v.769 S. Soeya;T. Imagawa;K. Mitsuoka;S. Narishige
  39. Phys. Rev. B. v.61 F. T. Parker;K. Takano;A. E. Berkowitz https://doi.org/10.1103/PhysRevB.61.R866
  40. IEEE Trans. Magn. v.31 T. Lin;C. Tsang;R. E. Fontana;J. K. Howard https://doi.org/10.1109/20.490063
  41. J. Magn. Soc. Jpn. v.21 M. Saito;Y. Kakihara;T. Watanabe;N. Hasegawa https://doi.org/10.3379/jmsjmag.21.505
  42. Ferromagnetism R. M. Bozorth
  43. W. H. Meiklejohn and C. P. Bean, Phys. Rev. 102, 1413 (1956); 105, 904 (1957). https://doi.org/10.1103/PhysRev.105.904