• Journal of Korean Vacuum Science & Technology
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• v.5 no.2
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• pp.43-46
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• 2001

Fe-Au alloys are characterized by the complete solubility, and exhibit an fcc-bcc structural transformation at the Fe-rich side. The magneto-optical(equatorial Ken effect : EKE) and optical properties of Fe$\_$1-x/Aux (0 < x < 1) were investigated in the 0.5 - 5.0 eV energy range. The x-ray diffraction study shows the structural fcc-bcc transformation about 80 at. % of Fe. Noticeable changes in the optical properties caused by the fcc-bcc structural transformation was observed. The shape and intensity of the EKE spectra as well as the field dependence of the magneto-optical response were also significantly changed. It is thought that these changes are mainly comes from the induced magnetic moment in Au(and/or the emhanced magnetic moment of Fe). The nature of the prominent structure observed in the UV range of the magneto-optical Ken effect of Au/Fe multilayered films are disscussed in connection with the above results.

• Journal of Magnetics
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• v.3 no.3
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• pp.78-81
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• 1998

Large magneto crystalline anisotropy energy and demagnetization energy of rare earth-transition metal (RF-TM) alloys play roles of bottlenecks towards their commercial applications for giant magnetostrictive and blue wavelength magneto optical recording materials, respectively. To solve the above problems, boron is added into amorphous RE-TM alloys to produce its electron transferring. The boron added amorphous RE-TM alloys show novel magnetic and magneto-optical properties as follows; 1) an amorphous $(Sm_{33}Fe_{76})$97B3 alloy obtains the magnetostriction of$ -550{times}10^{-6}$ at 400 Oe compared with saturation magnetostriction of$ -60{\times}10^{-6}$ in conventional Ni based alloys, 2) an amorphous$ (Nd_{33}Fe_{67})_{95}B_5$ alloy increases effective magnetic anisotropy to$ -0.5{\times}10^{-6} ergs/cm^3 from -3.5{\times}10^6 ergs/cm^3$ without boron, which correspond to the polar Kerr rotation angles of 0.52$^{\circ}$and 0.33$^{\circ}$, respectively. These results attribute to selective 2p-3d electron orbits exchange coupling (SEC).

• Journal of Magnetics
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• v.1 no.2
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• pp.86-89
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• 1996

The dc magnetron sputter deposited (Pt/Co/Pt/Ni) multilayers which exhibited Curie temperatures in the range of 150-$300^{\circ}C$ were studied as possible alternative multilayers for magneto-optical recording to the widely studied Co/Pt, whose Curie temperatures are in the range of 200~$400^{\circ}C$. The Coercivities of these multilayers were between 450 Oe and 800 Oe. These multilayers exhibited comparable magnetic and magneto-optical properties to Co/Pt multilayers with enhancement of the Kerr rotation at lower wavelengths and negligible Kerr ellipticity over a wide range of the spectrum (4000~7000$\AA$ ).

• Journal of the Korean Vacuum Society
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• v.7 no.s1
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• pp.1-6
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• 1998

The influence of the order-disorder structural transition on the magnetic and mageto-optical, and transport properties of Fe-Al and Co-Al alloy films has been investigated. The disordered states in the alloy films were prepared by vapor quenching deposition on glass substrates cooled by liquid nitrogen. The experimental study of the magento-optical properties of the ordered and disordered Fe-Al and Co-Al alloy films has been carried out in 1.05-5.0 eV energy range at room temperature. The transport properties have been measured in 2-300K temperature range with and without magnetic field of 0.5T. The influence of the order-disorder structural transition on the magnetic and magneto-optical properties was discussed by using the effective medium approximation and the structural defect approach. That on the temperature dependence of the resistivity was analyzed in a framework of the partial localization of the electronic states and the variable range hopping conductivity.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.05a
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• pp.13-16
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• 2003

Magnetic and magneto-optical properties of Fe/Pt/Fe, Co/Pd/Co trilayers and also the sandwiches with wedge-shaped magnetic (Fe, Co) and nonmagnetic (Pt, Pd) layers were investigated. The oscillatory behavior of the saturation field $H_{s}$ of the studied trilayers with changing the thickness of the nonmagnetic layer (NML) $t_{NML}$ was revealed. That was explained by the exchange coupling between ferromagnetic layers (FML) through the nonmagnetic spacer. For the first time, oscillations of the transverse Kerr effect (TKE) with changing the Pt- and Pd-wedge thickness were discovered. Period of these oscillations was found to depend on the FML thickness and the photon energy of the incident light. TKE spectra of the examined samples were discovered to modify very strongly with increasing $t_{NML}$. The discovered peculiarities of magneto-optical properties of thin-film systems were explained by a concept of the spin-polarized quantum well states in the pt and Pd layers.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.06a
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• pp.375-377
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• 1998

The magneto-optical properties of Co/Co$_2$TiSn two-phase magnet films were studied. These films show that relatively large Kerr rotations which are -0.4 deg. at the wavelength of 400 nm, compared to that of pure Co. It is conceivable that the magneto-optical effects may be due to both contributions of ferromagnetic Co matrix and ferromagnetic Co$_2$TiSn Heusler alloy precipitate. The perpendicular magnetization curve domonstrates a typical bubble domain hysteresis loop. the saturation magnetization change of the annealed film is less sensitive to temperature in the low temperature region and the Curie temperature of Co$_2$TiSn Heusler alloy precipitate is a little higher in the annealed film. These can be explained by the increase of the number of Co-Co exchange interaction in Heusler alloy structure resulting from the change of chemical ordering by annealing.

• Progress in Superconductivity
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• v.11 no.2
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• pp.128-134
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• 2010

The magnetic flux profiles in SmBCO and YBCO coated conductors(CC) in the presence of the external field were comparatively investigated by magneto-optic image and scanning hall probe measurements. The current distributions calculated by using the inversion method from measured field profiles show that the decrease of current densities near the edges of SmBCO CC is more significant than those of YBCO CC. Through the comparison of the numerical analysis based on Kim's critical state model and the Brandt and Indenbom's solution, we found that this feature is related to their different field dependant properties of the critical current densities.

• Proceedings of the Korean Magnestics Society Conference
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• 2003.12a
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• pp.235-235
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• 2003

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.23-24
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• 2006

Magnetic and magneto-optical properties of regioregular (>99%) poly(3-dodecylthiopenes are investigated. Faraday rotation of spin-coated films show extremely large Verdet constants, falling strongly with decreasing regioregularity. EPR spectroscopy at room temperature shows the presence of about 1 spin/190 monomers, indicative of delocalisation beyond a single polymer chain. SQUID measurements on the polymer give an effective magnetic moment of about 48900 mB, corrsponding to a S-value of 25.000. The Weiss-constant is 1.33 K indicating ferromagnetic coupling. Our experimental results show that organic polymer magnets can be prepared. Large MO effects allow the use of these materials in all-organic MO-sensors and devices.

• Journal of Magnetics
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• v.11 no.3
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• pp.143-146
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• 2006

We attempted to fabricate a new type of magneto optic spatial light modulator (MO-SLM) for multiple-tone modulation by using in-plane magnetization. In the MO-SLM, magnetic property of magneto-optical layer was modified to be suitable for multiple-tone expression by substituting Al in Bi:YIG film. At a driving current to 28 mA in an electrode of the fabricated MO-SLM, changes in brightness of pixels were observed using a polarization microscope.