The Korean Journal of Ceramics

The Korean Ceramic Society (한국세라믹학회)
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Fabrication of Bismuth- and Aluminum-Substituted Dysprosium Iron Garnet Films for Magneto-Optic Recording by Pyrolysis and Their Magnetic and Magneto-Optic Properties

  • Published : 1995.06.01
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Abstract

Polycrystalline bismuth- and aluminum- substituted dysporsium and yttrium iron garnet (Bi2R3-xAlyFe5-yO12, R=Dy or Y, $0\leqx\leq3, \; 0\leqy\leq3$) films have been prepared by pyrolysis. The crystallization temperatures, the solubility limit of bismuth ions into the garnet phase, and magnetic and magneto-optic properties of the films have been investigated as a function of bismuth and aluminum concentration. It was found that the crystallization temperatures as a function of bismuth and aluminum concentration. It was found that the crystallization temperatures of these films rapidly decreased as bismuth concentration. It was found that the crystallization temperatures of these films rapidly decreased as bismuth concentration (x) increased up to x=1.5 and then remained temperatures of these films rapidly decreased as bismuth concentration (x) increased up to x=1.5 and then remained unchanged at x>1.5, whereas, showed no changes as aluminum concentration (y) increased up to y=1.0 and then gradually increased at y>1.0. The solubility limit of bismuth ions was x=1.8 when y=0 but increased to x=2.3 when y=1.0. It was demonstrated that the magnetic and magneto-optic properties of the dysprosium iron garnet films could be tailored by bismuth and aluminum substitution suitable for magneto-optic recording as follows. The saturation magnetization and coercivity data obtained for the films indicated that the film composition at which the magnetic compensation temperature became room temperature was y=1.2 when x=1.0. Near this composition the coercivity and the squareness of the magnetic hysteresis loop of the films were several kOe and unit, respectively. The Curie temperatures of the films increased with the increase of x but decreaed with the increase of y, and was 150-$250^{\circ}C$ when x=1.0 and y=0.6-1.4. The Faraday rotation at 633 nm of the films increased as x increased but decreased as y increased, and was 1 deg/$\mu\textrm{m}$ when x=1.0 and y=1.0. Based on the data obtained, the appropriate film composition for magneto-optic recording was estimated as near x=1.0 and y=1.0 or $BiDy_2AlFe_4O_{12}$.

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References

  1. Proc. ICP-5 New Garnet Films with Giant Faraday Rotation M.Gomi;K.Satoh;M.Abe
  2. Ferromagnetic Materials v.2 A.H.Eshenfelder;E.P.Wohlfarth(ed.)
  3. Thin Solid Films v.114 Margnetic and Magneto-Optical Properties of Garnet Film P.Hansen;J.P.Krumme
  4. J. Magn. Soc. Jpn. v.13 no.Suppl Structure and Magneto Optical Properties of Bismuth-Substituted Garnet Films Prepared by Pyrolysis from Organic Solution J.Cho;M.Gomi;M.Abe
  5. Ferromagnetic Materials v.2 M.A.Gilleo;E.P.Wohlfarth(ed.)
  6. Handbook of Magnetic Materials S.Chikazumi(et al.)
  7. IEEE, Trans Magn. v.MAG-22 Magneto-Optic Properties of Bismuth-Substituted Garnet Films Prepared by Pyrolysis T.Mizuno;,M.Gomi
  8. Jpn. J. Appl. Phys. v.27 Microstructure of $Bi_{15}Y_{15}Fe_{5}O_{12}$ Films made by Pyrolysis J.Cho;M.Gomi;M.Abe
  9. Jpn. J. Appl. Phys. v.70 Bi-Substituted Iron Garnet Films with Fine Grains Prepared by Pyrolysis J.Cho;M.Gomi;M.Abe
  10. IEEE, Trans, Magn. v.MAG-20 Bismuth-Substituted Iron Garnet Filma Prepared by RF Diode Sputtering J.P.Krunime;V.Doormann;R.Eckart
  11. J. Appl. Phys. v.60 Selected-Area Sputter Epitaxy of Iron-Garnet Films J.P.Krumme;V.Doormann;B.Strocka;P.Willick
  12. Phys. Rev. Lett. v.28 Investigation of the Origin of the Anomalous Faraday Rotation of $Bi_{x}Ca_{35+0.5x}O_{12}$ by means of the Magneto-Optical Kerr Effect S.Wittekoek;D.E.Lacklison