• 한국자기학회지
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• 제16권1호
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• pp.1-5
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• 2006

결정구조는 같은 spinel 구조이나, 자기적으로는 각각 반강자성과 준강자성 특성을 띠고 있는 $Co_3O_4$와 자철광 $Fe_3O_4$의 혼성 Co-ferrite인 $Co_xFe_{1-x}O_4$ 박막을 sol-gel법으로 제조하여, Fe 이온에 대한 Co 이온 치환으로 발생된 양이온 거동이 Co-ferrite 박막의 결정구조 및 자기적 특성에 미치는 효과를 XRB 실험, VSM 측정, 그리고 Conversion Electron Mossbauer Spectroscopy (CEMS) 실험으로 조사하였다. 그 결과 $Co^{3+}$ 이온이 주로 $Fe^{3+}$ 이온을 치환하여 단위정의 크기가 감소를 가져오며, 결정구조는 inverse spinel 구조에서 normal spinel 구조로 변환된다. CEMS 분광실험을 통하여 확인된 Fe 이온의 site preference는 주로 $Fe^{3+}$ 이온이 $Co^{3+}$ 치환됨을 보여주고 있으며, 동시에 B-site의 $Co^{2+}$ 이온은 A-site로 이동된다. 자화곡선 측정결과 Co 조성값의 증가로 자기 moment값이 감소되는 것으로 나타났는데, 이것은 low spin상태의 $Co^{3+}$이 high spin상태의 $Fe^{3+}$이온을 치환하여 주로 발생한 것이다.

• 한국전기전자재료학회논문지
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• 제25권4호
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• pp.290-293
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• 2012

This article introduces the characterization of spin coated ZnO transparent conducting oxide on the flexible substrates. As a II-IV compound semiconductor, ZnO has a wide band gap of 3.37 eV with transparent properties. Due to this transparent properties, ZnO materials can be also employed as the transparent conducting electrode materials. Therefore, strong demands have been required for the transparent electrodes with low temperature processing and cheap cost. So, We will investigate the electrical property and optical transmittance of ZnO transparent conducting oxide through the 4-point probe resistivity meter, and ultraviolet-vis spectrometer Lamda 35, respectively.

• 공업화학
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• 제10권3호
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• pp.382-387
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• 1999

졸-겔법을 이용하여 무정형의 $V_2O_5$ 겔을 제조한 후, 스핀코우팅에 의하여 균일한 박막의 $V_2O_5$, xerogel 전극을 개발하여 전극의 임피던스 특성을 연구하였다. $V_2O_5$겔이 xerogel로 전환되는 과정에서 스핀코우팅 방법이 $V_2O_5$의 비등방성을 감소시킬 뿐만 아니라 우수한 전기화학적 특성을 갖게 하였다. $V_2O_5$ xerogel의 리튜이온 확산계수 및 전하이동저항은 xerogel내에 존재하는 리튬이온의 물분율이 변함에 따라 증감하였으며 가역성이 우수하였다.

• 천문학회보
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• 제44권2호
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• pp.45.2-45.2
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• 2019

The main-belt asteroid (5247) Krylov is known as a Non-Principal Axis (NPA) rotator. However, the shape model and spin state of this asteroid were not revealed. The physical model of an asteroid including spin state and shape is regarded to be important to understand its physical properties and dynamical evolution. Thus, in order to reconstruct the physical model of Kryolv, we applied the light curve inversion method using not only the optical light curves observed with ground-based telescopes in three apparitions during 2006, 2016, and 2017, but also the infrared light curves obtained with the Wide-field Infrared Survey Explorer (WISE) in 2010. We found that it is rotating in Short Axis Mode (SAM) with the rotation and precession periods of 368.71 hr and 67.277 hr, respectively. The orientation of the angular momentum vector is (298°, -58°) in the ecliptic coordinate system. The ratio of moments of inertia of the longest axis to the shortest axis is I_a/I_c = 0.36; the ratio of moments of inertia of the intermediate axis to the shortest axis is I_b/I_c = 0.96. Finally, the excitation level of this asteroid is found to be rather low with a ratio of the rotational kinetic energy to the basic spin state energy as E/E₀ ≃ 1.024. We will briefly discuss the possible evolutionary process of Krylov in this presentation.

• 비파괴검사학회지
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• 제28권6호
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• pp.524-530
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• 2008

The spin valve tunneling magnetoresistance (SV-TMR) sensor performance is analyzed using Stoner-Wohlfarth model for the detection of eddy current signals in nondestructive testing applications. The SV-TMR response in terms of the applied AC magnetic field dominantly generates the second harmonic amplitude in hard axis direction. The second harmonic eddy current signal detection using SV-TMR sensor shows higher performance than that of the coil sensor at lower frequencies. The SV-TMR sensor with high sensitivity gives a good solution to improve the low frequency performance in comparison with the inductive coil sensors. Therefore, the low frequency eddy current techniques based on SV-TMR sensors are specially useful in the detection of hidden defects, and it can be applied to detect the deeply embedded flaws or discontinuities in the conductive materials.

• Journal of Magnetics
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• 제2권3호
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• pp.72-75
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• 1997

The temperature dependent saturation magnetization curve of amorphous Fe67 Co18B14Si1, alloy was measured using a SQUID magnetometer and vibrating sample magnetometer from 5 K up to 800 K. Inelastic neutron neutron scattering measurements also have been used to study the long wavelength spin dynamics of this high Tc amorphous ferromagnetic alloy. The magnon dispersion curve exhibit the conventional quadratic relationship E = D (T) q2 + $\Delta$, typical of an iso=obtained from a low temperature magnetization curve, which was consistent with the value obtained from the analysis oif inelastic neutron scattering data after consideration of its temperature dependence.

• 한국자기학회지
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• 제5권6호
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• pp.952-955
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• 1995

It is well kown that the side-jump effect, originated from the spin-orbit scatterring of the transport electrons at the site of spin-orbit scatterers, is the reason for the anomalus Hall resistivity which is proportional to the magnetization. Our recent magnetization study implied that abundant ferromagnetic Fe clusters made of for Fe ions dominate the temperature and field dependence of magnetization at high field and low temperature regime for a paramagnetic $Fe_{0.33}Zr_{0.67}$ alloy. We measured the Hall resistivity of this alloy and observed that the Hall resistivity followed the M-H cure at low temperature, and the Hall coefficients at moderate temperatures were proportional to the magnetic susceptibility. We explain the behavior of Hall resistivity with the change of field and temperature in terms of side-jump effect.

• 한국재료학회:학술대회논문집
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• 한국재료학회 1997년도 한국재료학회 추계학술발표회
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• pp.89-89
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• 1997

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2014년도 자성 및 자성재료 국제학술대회
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• pp.149-150
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• 2014

• Nuclear Engineering and Technology
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• 제4권4호
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• pp.340-344
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• 1972

$^{79}$ Br, $^{80}$ Se, $^{103}$ Rh, $^{115}$ In 및 $^{133}$ Cs의 열중성자 포획시 혈성되는 이성체쌍의 비와 $^{79}$ Br, $^{80}$ Se 및 $^{l33}$Cs의 Epi-Cd 중성자 포획시 형성되는 이성체 쌍의 비를 측정하였다. 동 이성체비는 중성자 조사후 ${\gamma}$-선 분광분석법으로 얻은 붕괴곡선을 분석하여 측정하였다. 계측효율곡선은 전체불확실율이 악 1%인 표준선원을 사용하여 결정하였다. $\sigma$ high spin/($\sigma$ high spin+$\sigma$ low spin)으로 나타낸 열중성자로 생성된 $^{80, 80m}$Br, $^{81,81m}$Se, $^{014, 104m}$Rh, $^{116,116m}$In 및 $^{134, 134m}$Cs 쌍들의 이성체비는 각각 0.21$\pm$0.01, 0.14$\pm$0.02, 0.12$\pm$0.02, 0.69$\pm$0.07 및 0.058$\pm$0.004 이었다. Epi-Cd 중성자에 의해서 생성된 $^{80, 80m}$Br, $^{81,81m}$Se, 및 $^{134, 134m}$Cs 쌍의 이성체 비는 각각 0.19$\pm$0.02, 0.29$\pm$0.02 및 0,74$\pm$0,011 이었다. 실험적으로 얻은 본값을 통계적 모델로부터 얻은 이론치와 비교하여 본 결과 일반적인 일치를 보였다.다.