• Title/Summary/Keyword: 자기 이방성

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Brillouin Light Scattering Study of Magnetic Anisotropy in GaAs/Fe/Au System (Brillouin Light Scattering을 이용한 GaAs/Fe/Au 구조의 자기이방성)

  • Ha, Seung-Seok;You, Chun-Yeol;Lee, Suk-Mock;Ohta, Kenta;Nozaki, Takayuk;Suzuki, Yoshishige;Roy, W. Van
    • Journal of the Korean Magnetics Society
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    • v.18 no.4
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    • pp.147-153
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    • 2008
  • It has been well-known that the Fe/GaAs heterostructure has a small lattice mismatch of 1.4% between Fe and GaAs, and the Fe layer is grown epitaxially on the the GaAs substrate. There are rich physics are observed in the GaAs/Fe interface, and the spininjection is actively studied due to its potential applications for spintronics devices. We fabricated Fe wedge layer in the thickness range $0{\sim}3.4$ nm on the GaAs(100) surface with 5-nm thick Au capping layer. The magnetic anisotropy of the Fe/GaAs system was investigated by employing Brillouin light scattering(BLS) measurements in this study. The spin wave excitation of Fe layer was studied as the function of intensity and the in-plane angle of external magnetic field, and thickness of Fe layer. Also these various dependences were analyzed with analytic expression of spin wave surface mode in order to determine the magnetic anisotropies. It has been found that the GaAs/Fe/Au system has additional uniaxial magnetic anisotropy, while the bulk Fe has biaxial anisotropy. The uniaxial anisotropy shows increasing dependency respected to decreasing thickness of Fe layer while biaxial anisotropy is reduced with Fe film thickness. This result allows the analysis that the uniaxial anisotropy is originated from interface between GaAs surface and Fe layer.

Perpendicular Magnetic Anisotropy in Co/Pd Layer with TiO2 Seed Layer on the Various Substrates (TiO2 씨앗층을 이용한 다양한 기판에서의 Co/Pd 층의 수직 자기 이방성에 대한 연구)

  • Kang, Mool-Bit;Yoon, Jungbum;Lee, Jeong-Seop;You, Chun-Yeol
    • Journal of the Korean Magnetics Society
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    • v.23 no.1
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    • pp.7-11
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    • 2013
  • We investigate the perpendicular magnetic anisotropy in $TiO_2$/Co/Pd on GaAs(100), MgO(100), MgO(111), Si(100), and glass substrates. We find that the roughness of $TiO_2$ depends on the $O_2$ partial pressure in the magnetron sputtering process. The perpendicular magnetic anisotropies are found in all substrates with $TiO_2$ seed layer, and the perpendicular magnetic anisotropy of Co/Pd system is insensitive on the type of the substrate when the thickness of $TiO_2$ seed layer is thicker than 5 nm. However, MgO(111) substrate promotes $TiO_2$ rutile (111) structure, and it causes largest perpendicular magnetic anisotropy in $TiO_2$/Co/Pd(111) structures.

Magnetostriction and Magnetic Anisotropy Measurement Using High Efficiency Small EIectromagnet (고능률 소형 전자석에 의한 자왜 및 자기이방성 측정)

  • 이용호;신용돌;김병걸;민복기;송재성
    • Journal of the Korean Magnetics Society
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    • v.4 no.2
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    • pp.179-183
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    • 1994
  • A high efficiency small electromagnet (22 mm air gap and $40{\times}25mm^{2}$ core's cross section) suitable for measuring magnetostriction and magnetic anisotropy was biult. The magnet could be minaturized by reducing the measuring space and time. The excitation current of the electromagnet was supplied for only a few second of measuring time. Cooling system of the electromagnet could be eliminated since the dissipation energy was very small. An 0.5 T magnetic field was generated with 180 W power consumption. The values of magnetostriction and magnetic anisotropy were measured with a very sensitive capacitance cell with resolution of $10^{-8}$ and 1 nJ. The torque was calibrated using a soft magnetic ribbon's shape anisotropy.

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A Study on the Anisotropy Inhomogeneity of Permalloy Thin Films (퍼말로이 박막의 이방성불균일에 관한 연구)

  • 장평우;최태원;유성초;김희중
    • Journal of the Korean Magnetics Society
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    • v.7 no.4
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    • pp.186-190
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    • 1997
  • We measured an anisotropy inhomogeniety and dispersion of rf sputterd permalloy thin films by TBP(Transverse Biased Permeability) measurement method. Angular distribution function had a shape similar to the Lorentzian distribution, but magnitude distribution function deviates from the sysmetric Lorentzian distribution because of long tail to the region of a high Hk value. With increasing film thickness, the angular and magnitude anisotropy dispersion increased. The increase of angular dispersion was due to both the increase of grain size and local anisotropy in thicker films.

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