Journal of the Korean Ceramic Society (한국세라믹학회지)

The Korean Ceramic Society (한국세라믹학회)
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Nano-Granular Co-Fe-AI-O Soft Ferromagnetic Thin Films for GHz Magnetic Device Applications

  • Sohn, Jae-Cheon (Future Technology Research Division, Korea Institute of Science and Technology) ;
  • Byun, Dong-Jin (Department of Materials Science and Engineering, Korea University)
  • Published : 2006.03.01
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Abstract

Co-Fe-Al-O nanogranular thin films were fabricated by RF-magnetron sputtering under an $Ar+O_2$ atmosphere. High resolution transmission electron microscopy revealed that the Co-Fe-Al-O films are composed of bcc (Co, Fe) nanograins finer than 5 nm and an Al-O amorphous phase. A very large electrical resistivity of $374{\mu}{\Omega}cm$ was obtained, together with a large uniaxial anisotropy field of 50 Oe, a hard axis coercivity of 1.25 Oe, and a saturation magnetization of 12.9 kG. The actual part of the relative permeability was measured to be 260 at low frequencies and this value was maintained up to 1.3 GHz. The ferromagnetic resonance frequency was 2.24 GHz. The resulting Co-Fe-Al-O nanogranular thin films with a high electrical resistivity and high resonance frequency are considered to be suitable for GHz magnetic device applications.

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References

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