• 한국전기전자재료학회논문지
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• 제35권1호
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• pp.58-65
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• 2022

The field of liquid crystal display (LCD) is constantly in the spotlight and the process of depositing an alignment layer in the LCD manufacturing process is very important to obtain excellent performance such as low-power driving and high-speed response to improve LCD performance. Therefore, research on liquid crystal (LC) alignment is being actively conducted. When manufacturing LCD, it is necessary to consider the effect of the alignment layer thickness as one of the factors affecting various LCD performances. In addition, previous studies confirmed the LC alignment characteristics correlate with the rotation speed in the spin coating process. Therefore, the electro-optical properties of the LCD were investigated by manufacturing a polyimide alignment layer by varying the rotation speed in the spin coating process in this study. It was confirmed that the thickness of the polyimide alignment layer was controlled according to the spin coating conditions. The average transmittances of anti-parallel LC cells at the spin coating speed of 2,500 rpm and 3,000 rpm are about 60%, which indicates that the LC cell has relatively higher performance. At the spin coating speed of 3,000 rpm, the voltage-transmittance curve of twisted nematic (TN) LC cell was below 1.5 V, which means that the TN LC cell operated at a low power. In addition, high-speed operating characteristics were confirmed with a response time of less than 30 ms. From these derived data, we confirmed that the ideal spin coating speed is 3,000 rpm. And these results provide an optimized polyimide alignment layer process when considering enhanced future LCD manufacturing.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2000년도 International Symposium on Magnetics The 2000 Fall Conference
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• pp.325-326
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• 2000

Low temperature diagnosis was performed as a probe for the integrity of MTJ(Magnetic tunnel junction) process which is optimised for the given plasma oxidation condition. TMR ratio increased slowly with decreasing temperature than that expected from spin wave exitation theory〔1〕. Junction resistance (RJ) does not follow T$\^$-$\frac{1}{2}$/ law below 200 K, indicating another conduction path besides spin polarized tunneling is involved at low temperature. Temperature dependence of conductance dip and bias dependence of TMR with temperature are discussed, from which the quality of tunnel barrier and its formation process can be inferred.

• Journal of Magnetics
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• 제15권4호
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• pp.185-189
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• 2010

Spin polarized tunneling through a hybrid tunnel barrier of a Spin filter (SF) based on a EuO ferro-magnetic semiconductor and an organic semiconductor (OSC) (rubrene in this case) was investigated. For quasi-magnetic tunnel junction (MTJ) structures, such as Co/rubrene/EuO/Al, we observed a strong spin filtering effect of the EuO layer exhibiting I-V curves with high spin polarization (P) of up to 99% measured at 4 K. However, a magnetoresistance (MR) value of 9% was obtained at 4.2 K. The low MR compared to the high P could be attributed to spin scattering caused by structural defects at the interface between the EuO and rubrene, due to nonstoichiometry in the EuO.

• 대한화학회지
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• 제24권2호
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• pp.139-145
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• 1980

마크로사이클리간드인 1,4,8,11-테트라아자사이클로테트라데칸 (cyclam)과 비환형 리간드인 1,5,8,12-테트라아자도데칸 (3,2,3-tet)의 높은 스핀철(Ⅱ) 착화합물이 합성되었다. 낮은 스핀인 $[Fe(cyclam)(CH_3CN)_2](ClO_4)_2$는 메탄올속에서 염소이온과 반응하여 높은 스핀인 $[Fe(cyclam)Cl]ClO_4$를 생성한다. $[Fe(cyclam)(CH_3CN)_2](ClO_4)_2$는 낮은 스핀이지만 $[Fe(3,2,3-tet)(CH_3CN)_2](ClO_4)_2$는 높은 스핀을 가지며 이 차이는 비환형 리간드가 환형 리간드보다 압축효과가 작은 것으로 설명된다. $[Fe(cyclam)Cl]ClO_4$의 합성은 마크로사이클리간드가 불포화되어 있거나 치환체가 있어야 높은 스핀 다섯배위철(II) 착화합물의 합성이 가능하다는 지금까지의 전해에 반대되는 증거가 된다. $[Fe(cyclam)Cl]ClO_4$와 $[Fe(3,2,3-tet)(CH_3CN)_2](ClO_4)_2$는 일산화탄소와 반응해서 각기 낮은 스핀 여섯배위인 $[Fe(cyclam)Cl(CO)]ClO_4$ 와 $[Fe(3.2,3-tet)(CH_3CN)(CO)](ClO_4)_2$를 만든다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
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• pp.1054-1056
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• 2002

High temperature Kermal diffusion from $POCl_3$ source usually used for conventional process through put of a cell manufacturing line and potentially reduce cell efficiency through bulk like time degradation. To fabricate high efficiency solar cells with minimal thermal processing, spin-on-doping(SOD) technique can be employed to emitter diffusion of a silicon solar cell. A technique is presented to emitter doping of a mono-crystalline solar cell using spin-on doping (SOD). Moreover it is shown that the sheet resistance variation with RTA temperature and time fer mono-crystalline and multi-crystalline silicon samples. This novel SOD technique was successfully used to produces 11.3% efficiency l04mm by 104mm size mono-crystalline silicon solar cells.

• 한국자기공명학회논문지
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• 제19권1호
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• pp.11-17
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• 2015

The Kubo formalism and utilizing the projection operator technique (POT) introduced by Kawabata, the electron spin resonance (ESR) line-shape formula for carbon nanotubes through the hyperfine interaction introduced earlier in terms of POT. We can see that the line-width decreases exponentially as the temperature increases. The spin relaxation time show gradual decrease as magnetic field becomes larger. The analysis reveals the peculiarities in spin relaxation inherent to one dimensional system at low temperature and weak magnetic fields. Thus, the present technique is considered to be more convenient to explain the carbon nanotubes as in the case of other optical transitions.

• 대한화학회지
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• 제23권2호
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• pp.65-74
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• 1979

팔면체$ [Ti(Ⅲ)A_3B_3]$, $ [V(Ⅲ)A_3B_3]$, $ [Fe(Ⅲ)A_3B_3]$ 및 $ [Ni(Ⅱ)A_3B_3]$ 형태 착물의 바닥상태에 대한 리간드 궤도함수의 spin-orbit coupling의 영향을 고찰하여 보았다. 리간드 궤도함수의 spin-orbit coupling이 바닥상태의 파동함수에는 영향을 주지 않았으나 에너지 준위의 분열에는 영향을 주었으며, 그 크기는 Ti(Ⅲ) > V(Ⅲ) > Fe(Ⅲ)의 순서로 감소하였다

• Journal of Magnetics
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• 제3권4호
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• pp.105-111
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• 1998

The low energy excitations of spin waves (SWR) in thin films can be used for determination of the surface anisotropy constant and the nonhomogeneities of magnetization in the close-to-surface layer. The dispersion relation in SWR is sensitive on the geometry of experiment. We report on temperature dependence of surface magnetic anisotropy energy constant in magnetic semiconductor thin films of$ CdCr_{2-2x}In_{2x}Se_4$ at spin glass state. Samples were deposited by rf sputtering technique on Corning glass substrate in controlled temperature conditions. Coexistence of the infinite ferromagnetic network (IFN) and finite spin slusters (FSC) in spin glass state (SG) is know phenomena. Some behavior typical for long range magnetic ordering is expected in samples at SG state. The spin wave resonance experiment (microwave spectrometer at X-band) with excited surface modes was applied to describe the energy state of surface spins. We determined the surface magnetic anisotropy energy constant versus temperature using the surface inhomogeneities model of magnetic thin films. It was found that two components contribute to the surface magnetic anisotropy energy. One originates from the exchange interaction term due to the lack of translation symmetry for surface spin as well as from the originates from the exchange interaction term due to the lack of translation symmetry for surface spin as well as from the stray field of the surface roughness. The second one comes from the demagnetizing field of close-to surface layer with grad M. Both term linearly decrease when temperature is increased from 5 to 123 K, but dominant contribution is from the first component.

• Journal of Magnetics
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• 제2권3호
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• pp.96-100
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• 1997

A spin valve structure of NiO(40 nm)/Co(2 nm)/Cu(2.6 nm)/Co(x nm)/Ta(5 nm) has been investigated for the application of magnetic random access memory (MRAM). The spin valve structure exhibited very large difference in the coercivities between pinned and free layers, a relatively high GMR ratio, and a low free layer coercivity. The spin valves were prepared by sputtering and were characterized by dc 4-point probe, and VSM. The spin valves with combined free layer exhibited a maximun GMR ratio of 10.4% with a free layer coercivity of about 82 Oe. The spin valves with a single 10 nm thick a-CoNbZr free layer exhibited a GMR ratio of about 4.3% with a free layer coercivity of about 12 Oe. The GMR ratio of the spin valves increased by addition of Co between Cu and a-CoNbZr. It has been confirmed that the coercivity of free layer can be decreased by increasing the thickness of a-CoNbZr. It has been confirmed that the coercivity of free layer can be decreased by increasing the thickness of a-CoNbZr layer without losing the GMR ratio substantially, which was mainly due to high resistivity of the amorphous "layers".

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 추계학술대회 논문집
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• pp.68-69
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• 2007

To make cost-effective solar cells, We have to use low cost material or make short process time or high temperature process. In solar cells, formation of emitter is basic and important technique according to build-up P-N junction. Diffusion process using spin-on dopants has all of this advantage. In this paper, We investigated n+ emitter formation spin-on dopants to apply crystalline silicon solar cells. We known variation of sheet resistance according to variation of temperature and single-crystalline and multi-crystalline silicon wafer using Honeywell P-8545 phosphorus spin-on dopants. We obtain uniformity of sheet resistance within 3~5% changing RPM of spin coater.