• Title/Summary/Keyword: GMR

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Analysis of GMR Phenomenon by Asymmetric Multi-layered Dielectric Gratings (비대칭 다층 유전체 격자구조에 의한 GMR 현상의 분석)

  • Ho, Kwang-Chun
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.17 no.3
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    • pp.209-214
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    • 2017
  • A plane-wave incident upon asymmetric multi-layered dielectric grating as well as symmetric grating structure generates space harmonics. Selected space harmonics among those harmonics can undergo strong resonance scattering variations known as GMR(guided-mode resonance). In this paper, to clarify these effects, the field propagation and dispersion curve inside the grating region are analyzed by using a rigorous equivalent transmission-line theory(RETT) based on eigenvalue problem. The results show that, at the peak of a scattering resonance, the reflected mode is almost identical to a leaky wave that can be supported by the grating structure. Thus, it confirms to be occurred GMR effect associated with the free-resonant character of leaky waves at asymmetric multi-layered dielectric gratings. Quantitative simulation results illustrating the behavior of typical gratings are given, and the special case of normal incidence is discussed for TE and TM modes.

Post Annealing Treatment Introducing an Isotropy Magnetorsistive Property of Giant Magnetoresistance-Spin Valve Film for Bio-sensor (바이오센서용 거대자기저항-스핀밸브 박막이 등방성 자기저항 특성을 갖게 하는 후열처리 조건 연구)

  • Khajidmaa, P.;Park, Kwang-Jun;Lee, Sang-Suk
    • Journal of the Korean Magnetics Society
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    • v.23 no.3
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    • pp.98-103
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    • 2013
  • The magnetic easy axis of the ferromagnetic layer for the dual-type GMR-SV (giant magnetoresistance-spin valve) having NiFe/Cu/NiFe/IrMn/NiFe/Cu/NiFe multuilayer structure controlled by the post annealing treatment. The magnetoresistive curves of a dual-type IrMn based GMR-SV depending on the direction of the magnetic easy axis of the free and the pinned layers are measured by the different angles for the applied fields. By investigating the switching process of magnetization for an arbitrary measuring direction, the optimum annealing temperature having a steady and isotropy magnetic sensitivity of 2.0 %/Oe was $105^{\circ}C$. This result suggests that the in-plane orthogonal magnetization for the dual-type GMR-SV film can be used by a high sensitive biosensor.

Magnetoresistance Properties of Hybrid GMR-SV Films with Nb Buffer Layers (Nb 버퍼층과 거대자기저항-스핀밸브 하이브리드 다층박막의 자기저항 특성)

  • Yang, Woo-Il;Choi, Jong-Gu;Lee, Sang-Suk
    • Journal of the Korean Magnetics Society
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    • v.27 no.3
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    • pp.82-86
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    • 2017
  • The IrMn based GMR-SV films with three different buffer layers were prepared on Corning glass by using ion beam deposition and DC magnetron sputtering method. The major and minor magnetoresistance curves for three different buffer layers beneath the structure of NiFe(15 nm)/CoFe(5 nm)/Cu(2.5 nm)/CoFe(5 nm)/NiFe(7 nm)/IrMn(10 nm)/Ta(5 nm) at room temperature have shown different magnetoresistance properties. When the samples were annealed at $250^{\circ}C$ in vacuum, the magnetoresistance ratio, the coercivity of pinned ferromagnetic layer, and the interlayer coupling field of free ferromagnetic layer were enhanced while the exchange bias coupling field did not show noticeable changes.

Regional Distribution of Isotropy Magnetic Property of Dual-type Giant Magnetoresistance-Spin Valve Multilayer (이중구조 거대자기저항-스핀밸브 박막의 자기등방성 영역분포에 관한 연구)

  • Khajidmaa, Purevdorj;Lee, Sang-Suk
    • Journal of the Korean Magnetics Society
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    • v.23 no.6
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    • pp.193-199
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    • 2013
  • The regional distribution of magnetic isotropy depending on the post annealing condition for the dual-type structure GMR-SV (giant magnetoresistance-spin valve) of NiFe/Cu/NiFe/IrMn/NiFe/Cu/NiFe multilayer was investigated. The rotation of in-plane ferromagnetic layer induced by controlment of the post annealing temperature inside of the vacuum chamber. The magnetoresistive curves of a dual-type IrMn based GMR-SV depending on the direction of the magnetization easy axis of the free layer and the pinned layer are measured by between $0^{\circ}$ and $360^{\circ}$ angles for the applied fields. The optimum annealing temperature having a steady and isotropy magnetic sensitivity of 1.52 %/Oe was $107^{\circ}C$ in the rotational section of $0{\sim}90^{\circ}$. By investigating the switching process of magnetization for an arbitrary measuring direction, the in-plane orthogonal magnetization for the dual-type GMR-SV multilayer can be used by a high sensitive biosensor for detection of magnetized micro-beads.