• Title/Summary/Keyword: magneto-optic

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Fabrication and Sensor Properties of Garnet Thin Films for Magneto-Optic Electrical Current and Magnetic Field Sensor (광자기 전류 자장 센서용 가넷 박막의 제조 및 센서 특성)

  • 김덕실;조재경
    • Journal of the Korean Magnetics Society
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    • v.8 no.2
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    • pp.74-78
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    • 1998
  • High quality single cystal Bi, Gd : YIG films have been grown on GCMZGG wafers by LPE techniques. The magnetic, magneto-optic and sensor properties of the films have been investigated. The films showed high linearity with almost no hystersis, saturaton Faraday rotation angle of 45$^{\circ}$, saturation field of about 1.1 kOe, Verdet constant of 5.6$^{\circ}$ /(Oe, cm) at room temperature, and temperture coefficient of Verset constant of 0.0056$^{\circ}$ /(Oe, cm, $^{\circ}C$) in the range of 0 $^{\circ}C$~100 $^{\circ}C$. The sensor made out of the film exhibited highly linear signal in the range of 3 A-300 A.

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Nonlinear magneto-optic effect based on atomic coherence in Rb D1-line (Rb D1 전이선에서 원자결맞음에 의한 비선형 광자기 효과)

  • Moon, H.S.;Lee, W.K.;An, M.H.;Kim, J.B.
    • Korean Journal of Optics and Photonics
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    • v.16 no.1
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    • pp.7-12
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    • 2005
  • We have observed the nonlinear magneto-optic effect(NMOE) based on atomic coherence in $^{87}$ Rb D$_1$-line using the Rb vapor cell containing 50 Torr of Ne. The width of the NMOE signal was measured to be 2$\pi$${\times}$464 Hz, when the peak-to-peak B-field variation was 1 mGauss. The result of this work may be applied to a high-sensitivity magnetometer.

The characteristics of nonlinear magneto-optical effect based on coherent population trapping in the D1 line of Rh atoms (87Rb D1 전이선에서 원자결맞음을 이용한 비선형 광자기 효과 신호의 특성)

  • Lee, L.;Moon, H.S.;Kim, J.B.
    • Korean Journal of Optics and Photonics
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    • v.17 no.1
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    • pp.1-6
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    • 2006
  • We investigated the characteristics of the nonlinear magneto-optic effect (NMOE) depend on the transitions, the laser intensity and the temperature of the vapor cell, in the $D_1$ transition of $^{87}Rb$ atoms by using the Rb vapor cell contained with buffer gas of Ne 6.7 kPa. The size and the width of NMOE signal were increased according to the light intensity and temperature in the transition of F=2$\to$F'=2. However, In the case of using the F=2$\to$F'=1 transition, the size of the signal could be increased according to the light intensity without additional broadening of the width. We confirmed that the sensitivity of detecting small magnetic flux improved in this transition, and explained these effects by the different of the CPT configuration between Zeeman sublevels. At the optimal condition in experiment, the sensitivity of this system was evaluated less then $70pT/\sqrt{Hz}$.

Dependence of Magnetic and Magneto-Optic Properties on Deposition Angle in E-Beam EVaporated Co/Pt Multilayer Films (전자빔 증착 Co/Pt 다층박막에서 입사 선속의 방향에 따른 자기 및 자기광학적 성질 변화 연구)

  • 문기석;신성철
    • Journal of the Korean Magnetics Society
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    • v.4 no.4
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    • pp.313-318
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    • 1994
  • We have investigated the effects of deposition angle on magnetic and magneto-optic properties in Co/Pt multilayer thin films. which were prepared bye-beam evaporation on tilted substrates. with varying tilt angle from $0^{\circ}$ to $60^{\circ}$. The structure of the specimens was examined by x-ray diffractometer and scanning electron microscope. and the magnetic and magneto-optical properties were measured by VSM, torque magnetometer, and Kerr loop tracer. X-ray diffractometry revealed that all of the specimens had multilayer structure and growth orientation of column followed the tangent rule but the crystallograpic orientation, <111>, was slightly deviated from the substrate normal even though the deposition angle was increased up to $60^{\circ}$. A decrement of the magnetization and Kerr angle with the deposition angle was related with that of the film density due to increasing porosity. The perpendicular mag¬netic anisotropy was also decreased with increasing the deposition angle.

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A Study on Direct Current Measurement Using Magneto-Optical LMF Method (자기장학 누설자속법을 응용한 직류전류계측법에 관한 연구)

  • Lee, Jin-Yi
    • Journal of the Korean Society for Nondestructive Testing
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    • v.24 no.6
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    • pp.566-572
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    • 2004
  • It is necessary to measure the direct current with a non-contact methodology for the liquid or gas phase, as welt as the conducting metals. This paper described a theoretical consideration and experimental verification for a non-contact quantitative direct current measurement system using the Faraday effect and magnetic flux leakage. The leakage of magnetic flux occurs around a gap when a ferromagnetic core including the discontinuous gap is magnetized. Two large anisotropic domains in a magneto-optical film are occurred by the vertical component of leaked magnetic flux and the domain walls are paralleled to the center of the gap. Here, the symmetrical arrangement of domains are deflected when a vertical magnetic field is applied to the magneto-optical film. The domain wall of the magneto-optical film are relocated when a measuring current passes through the ferromagnetic core. Therefore, a direct current passing through the core can be determined quantitatively by the measurement of moving distance of the domain wall.