• Journal of Electrochemical Science and Technology
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• 제2권2호
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• pp.103-109
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• 2011

Nanocrystalline $LiFePO_4$ powders were prepared at 660-$670^{\circ}C$ in an Ar atmosphere using two different synthetic routes, solid-state and sol-gel. Both materials showed well-developed XRD patterns without any impurity peaks. Particles composed in the range of 200-300 nm from the solid-state method, and 50-100 nm from the sol-gel method, were confirmed through scanning electron microscopy and dynamic light scattering. The $LiFePO_4$ obtained by the sol-gel method offered a high discharge capacity (153 mAh/g) and stable discharge behavior, even at elevated temperatures (50 and $60^{\circ}C$), whereas poor electrochemical performance was observed from the solid-state method. Rate capability studies for sol gel-derived $LiFePO_4$ ranged from 0.2 to 30 C, which revealed excellent retention over 70 cycles with a 99.9% capacity.

• 한국세라믹학회지
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• 제33권12호
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• pp.1301-1310
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• 1996

Generally it requires high sintering temperatures more than 135$0^{\circ}C$ to make semiconductive BaTiO3 ceramics. Also it is very difficult to achieve a homogeneous mixing in solid-state reaction method. Therefore the liquid phase distributed to non-uniform dilute the characteristics of PTCR. In order to improve the uniformity this study is used the sol-gel coating method. Using this method we studied the new manufacturing process that had a high reproducibility and mass production capability. Tetraethyl orthosilicate (TEOS) was used as a source of Si. The semiconductive BaTiO3 ceramics which was produced by sol-gel method for the SiO2 addition and sintered between 124$0^{\circ}C$ and 130$0^{\circ}C$ showed almost same resistivity at room temperature among 125$0^{\circ}C$ and 130$0^{\circ}C$. As the results We could be sintered the semiconducting BaTiO3 ceramics at lower temperature even at 125$0^{\circ}C$ maintaining the same specific resistivity ratio ($\rho$max/$\rho$min) at 130$0^{\circ}C$. The specific resistivity both below and above the Curie temperature were increased by slow cooling and the steepness of the plots in the reasion of transition from low to high resistance increased as the cooling rate decreased.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.390-390
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• 2010

We fabricate Schottky diodes with the contact between a sol-gel derived ZnO layer and Au that guarantees the expected Schottky contact due to the high work function. The formed single metal Schottky barrier shows characteristics comparable to the barrier formed by alloys. Au is deposited by thermal evaporation on a ZnO thin film that is optimally formed under sol-gel process conditions of a 1-mol zinc acetate concentration and a 3000-rpm coating speed. Possible defects. which can provide deleterious current paths. are minimized by patterning the deposited Au. The I-V curve verifies the formation of a Schottky contact. Measurements showed that the Schottky barrier height and leakage current at -5 V were 0.6 eV and $1{\times}10^{-12}A$. respectively.

• Korean Chemical Engineering Research
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• 제46권1호
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• pp.112-117
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• 2008

1:1로 몰 비가 조절된 glycidoxypropyl trimethoxysilane(GPTMS)과 methyl triethoxysilane(MTES)을 출발물질로 하여 sol-gel법에 의해 유-무기 혼성 용액을 제조하였다. 이 용액에 spiropyran계 광 변색 염료를 ethylacetate(EA)에 용해시킨 용액을 혼합하여 광 변색 코팅 용액을 제조하였다. 그 후 기재인 polycarbonate 시트에 스핀 코팅 시키고 $100^{\circ}C$에서 2 h 동안 열 경화 시켜 광 변색 코팅 막을 제조하였다. 코팅 막은 UV 광을 조사함에 의해 가역적인 색변화를 보여주었다. 이때 코팅 막의 소색속도는 코팅 용액 중의 EA의 첨가량이 증가됨에 따라 증가하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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• pp.288-289
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• 2006

We studied the effect of sol-gel processing and sintering temperature on the microwave properties of $MgCo_2(VO_4)_2$ system(MCV) which is applicable to LTCC(low-temperature cofired ceramics). The MCV was synthesized by sol-gel process using solution that contains precursor molecules for Mg, Co, and V. SEM analysis shows that the average particle size is ${\sim}1{\mu}m$ and size distribution is very uniform compared to the one prepared by conventional solid-state reaction process. Highly dense samples were obtained at the sintering temperature range of $750^{\circ}C{\sim}930^{\circ}C$. The maximum $Q{\times}f_0$ value of 55,700GHz, dielectric constant(${\varepsilon}_r$) of 10.41 and temperature coefficient(${\tau}_f$) of $-85ppm/^{\circ}C$ was obtained at the sintering temperature of $930^{\circ}C$. The superior microwave properties of sol-gel processed MCV relative to conventional solid-state reaction processed one is remarkable especially at lower sintering temperatures such as $750^{\circ}C$ and $800^{\circ}C$.

• 전기화학회지
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• 제3권1호
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• pp.11-14
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• 2000

가시광선 영역에서의 높은 투과성과 우수한 전도성을 가진 전도성 ITO박막은 그 전기적 광학적 특성에 의해서 태양 전기 기판의 전극 재료나 Display소자의 투명전극으로 개발되고 있다. 이들의 제작은 현재 sputtering이 주종을 이루나 이들의 높은 생산비를 절감할 목적으로 sol-ge떫을 이용하여 ITO박막을 만들었다. ITO제조용 sol은 유기질 sol로는 indium tri-iso-propoxide를 ethylene glycol monoethyl ether에 녹인 후 $SnCl_4$를 dopant로 사용하여 제조하였다. Acetyl acetone을 넣어 sol이 수화되는 현상을 억제하였다. 무기질 sol로는 indium acetate를 n-propanol에 용해하여 사용하였다. Spin 방법을 이용하여 코팅하였으며 $500^{\circ}C$에서 열처리하였다. 가시 광선 영역에서의 투과도는 $90\%$ 이상을 얻었으며 비저항은 $0.01\Omega{\cdot}cm$가 측정되었다.

• 한국결정성장학회지
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• 제8권3호
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• pp.468-473
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• 1998

Sol-gel법을 이용하여 PbTiO3에 La을 10mol% 도핑한 박막을 bare Si(100)-wafer 위에 스핀 코팅법을 이용하여 제조하였다. 제조된 박막의 열처리 온도에 따른 결정화 거동을 살펴보고, 씨앗층(seeding layer)을 도입하여 박막의 미세구조 및 배향성을 SEM과 XRD로 관찰하였다. 씨앗층없이 일반적으로 제조된 박막의 경우는 우선 배향성을 나타내지 않았으나, 씨앗층을 도입한 경우에는 씨앗층의 두께 및 열처리 시간에 따라 막의 배향성이 달라졌다.

• 한국세라믹학회지
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• 제24권5호
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• pp.447-452
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• 1987

${\alpha}$-Al2O3 powder was produced at 1000$^{\circ}C$ by the boehmite sol-gel process with seeding 2 wt% ${\alpha}$-Al2O3. The processes and mechanisms of fornation of ${\alpha}$-Al2O3 was investigated using DTA/TG, XRD, TR spectroscopy and thermodynamic analysis. The specific surface area of the obtained ${\alpha}$-Al2O3 was 16.3㎡/g.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2003년도 춘계학술발표강연 및 논문개요집
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• pp.55-55
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• 2003

Recently, with the rapid development of the waveguide division multiplexing (WDM) systems for large capacity and flexibility of information network, the broad band 1.5$\mu\textrm{m}$ erbium-doped waveguide amplifier (EDWA) become important. The main factors affecting the performance of sol-gel-based waveguides are non-radiative relaxation channels due to rare-earth concentration quenching and to vibration of the OH groups Therefore, the sol-gel process has to be carefully controlled in order to minimize the residual OH content.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 추계학술대회 논문집 전기물성,응용부문
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• pp.140-141
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• 2003

졸겔법은 건식공정에서 습식공정으로 마이크로 단위에서 나노 단위로의 전환을 의미하는 정밀세라믹스의 제조공정에 새로운 개념으로서 세라믹스의 초기 제조공정에 표면이나 계면을 조절함으로써 재료내에 이들로 인해 발생하는 불균질을 제거하여 우수한 물성의 세라믹스를 얻고자 하는 것이다. 본 논문에서는 고출력 레이저 발진용 매질로 각광받고 있는 Nd:glass를 기존의 건식공정인 용융법대신 습식공정인 sol-gel process를 이용하여 제조하고자 연구하였다.