• 통합자연과학논문집
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• 제12권4호
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• pp.101-104
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• 2019

A hydrated strontium iron fluoride, Sr₂Fe₂F₁₀(H₂O) has been synthesized and characterized. The material was synthesized through mild hydrothermal reaction using an aqueous CF₃COOH solution. The material exhibits a one-dimensional structure consisting of chains of corner-shared Fe³⁺F₆ octahedra, isolated Fe³⁺F₅(H₂O) octahedra, chains of SrF₁₀ polyhedra and isolated SrF₈ polyhedra, respectively. Magnetic property measurements on Sr₂Fe₂F₁₀(H₂O) reveals an antiferromagnetic order at T_N of ~2.5 K with a Weiss temperature (θ) of -61.51 K.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집
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• pp.482-485
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• 2002

We synthesize a (Y,Sm)BCO(its composition is (Y/Sm123+0.4Y/Sm211)+1wt%CeO$_2$) powders using polymeric complex method. (Y,Sm)BCO powders are prepared as heated at 970$^{\circ}C$. For measurement of this characterization, We measure XRD and SEM. We use TSMG method for fabricatlon of (Y,Sm)BCO single crystal. The manufactured VBCO single crystal is measured by a magnetic distribution device using 0.5 Tesla magnet. As the result of this measurement, we find that a trapped magnet fields are 550 Gauss.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집
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• pp.499-502
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• 2002

We synthesized Y$\sub$1.8/Ba$\sub$2.4/Cu$\sub$3.4/O$\sub$x/(Y123+Y211+1wt% CeO$_2$) powders using Polymeric Complex method and used raw materials; Y$_2$O$_3$, BaCO$_3$, CuO and CeO$_2$. It was formed by calcination at 850 $^{\circ}C$ for 24h in air. In comparison of solid-state method, sol-gel method etc., synthesis temperature decreased up to 100$^{\circ}C$.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.2
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• pp.1022-1025
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• 2003

본 연구에서는 저온 동시 합성법을 이용하여 ITO 나노 분말을 제조하였다. 저온 동시 합성법은 기존의 염화 인듐 및 염화 주석 염이 아닌 인듐 및 주석 유기물 염들을 사용하므로 기존의 $600{\sim}700^{\circ}C$가 아닌 $300^{\circ}C$ 이하에서 공정이 가능하고, 이로써 초미세급의 나노 분말을 얻을 수 있다. 또한 두가지 유기물 염을 동시에 산화시킴으로써 한번에 동시 합성이 가능하다. 이러한 저온 동시 합성법으로 제조한 나노 분말을 분석한 결과 분말의 크기는 평균 5 nm, 비 표면적은 약 $104m^2/g$ 이었다. 또한 EDS 및 XRD 분석 결과 분말의 결정상은 $In_2O_3$ 격자 내에 $3{\sim}8%$의 Sn이 고용된 [222], [400], [440]의 입방정 구조인 고품질의 ITO 나노 분말을 제조할 수 있었다.

• 한국세라믹학회지
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• 제32권1호
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• pp.71-82
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• 1995

The weathered two-mica granite is widely distributed in Korea and called a kind of ground rock for kaolin. The major minerla compositions are consist of this quartz, feldspar, mica and clay mineral. At present, only a small portion of this granite is used as the material for the low-grade tile industry due to the low S.K. value and the high contents of impurities such as Fe2O3 and FeO. The low S.K. value is caused by feldspars not weathered to clay minerals. The refinement of this thus has been required for the recent shortage of the resources of high-grade one. This paper concerns an optimum hydrothermal treatment condition to refine the low-grade weathered two-mica granite of which impurities are feldspar mineral and Fe2O3. FeO components in using for the main material of ceramic industry. And then, from this result, we tried to fine out the basic formation mechanism of clay mineral from feldspar etc and develope the effectual utilization method of this.

• 한국전기전자재료학회논문지
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• 제29권11호
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• pp.685-689
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• 2016

Synthesis of the fluorescent Au nanoclusters is reported. The Au nanoclusters were synthesized via reduction of gold ions in reverse micelles with mild reducing agents. The Au nanoclusters show a bright red emission at 640 nm. The fluorescent Au nanoclusters attract great interest for sensor, electronic device and bio-imaging applications because of ultra-small size, high chemical stablity and bright emission. We believe that the fluorescent Au nanoclusters can have optoelectronic applications such as optical down conversion phosphors.

• Journal of Advanced Marine Engineering and Technology
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• 제39권8호
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• pp.833-837
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• 2015

Li-air batteries have a promising future for because of their high energy density, which could theoretically be equal to that of gasoline. However, substantial Li-air cell performance limitations exist, which are related to the air cathode. The cell discharge products are deposited on the surfaces of the porous carbon materials in the air electrode, which blocks oxygen from diffusing to the reaction sites. Hence, the real capacity of a Li-air battery is determined by the carbon air electrode, especially by the pore volume available for the deposition of the discharged products. In this study, a simple and fast method is reported for the large-scale synthesis of carbon nanoballs (CNBs) consisting of a highly mesoporous structure for Li-air battery cathodes. The CNBs were synthesized by the solution plasma process from benzene solution, without the need for a graphite electrode for carbon growth. The CNBs so formed were then annealed to improve their electrical conductivity. Structural characterization revealed that the CNBs exhibited both an pore structure and high conductivity.

• 한국전기전자재료학회논문지
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• 제29권12호
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• pp.737-749
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• 2016

Recently perovskite materials with much cheaper cost and marvellous optoelectronic properties have been studied for next generation LED display devices overseas. Technology development trends of inorganic $CsPbX_3$(X=halogen) based LEDs (PeLEDs) with assumed high stability were investigated on literature worldwide. It was found that syntheses methods of these nanocrystals (NCs, mainly quantum dots, QDs) made great progress. A new room temperature synthesis method showed outstanding PL (photoluminescence) properties such as high quantum yield (QY), narrow emission width, storage stability comparable with, or often exceeding those of conventional hot injection method and CdSe@ZnS type inorganic colloidal QDs. PeLEDs with shell layers might be more promising, indicating urgent real research start of this solution processing technology for small businesses in Korea.

• 한국전기전자재료학회논문지
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• 제16권2호
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• pp.125-130
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• 2003

TiO$_2$ nanoparticles were prepared by photochemical synthesis in the dry toluene. The shape and size of the amorphous TiO$_2$ nanoparticles were investigated by transmission electron microscope. The particle size was varied by the contents of the titanium (IV) isopropoxide in dry toluene. Especially networked TiO$_2$ particles were formed from 40% titanium (IV) isopropoxide solution. The optical absorption spectra, photoluminescence, and PL excitation spectra of TiO$_2$ in dry toluene were obtained. The were shifted to the short wavelength as the contents of TiO$_2$ were increased. PL excitation had the peak at the wavelength regions is which the absorption increased steeply.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 춘계합동학술대회 논문집
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• pp.218-223
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• 2002

Low temperature synthesis of $LaNiO_3$ crystalline phase composited from mixtures of $La_2O_3$ and NiO via the ball mill and mechanochemical process were investigated. By the ball mill, 20% of $LaNiO_3$ crystalline phase was formed in the samples sintered at $900^{\circ}C$ due to the lack of reactivity of NiO. However, the mechanochemical process yielded about 93% of $LaNiO_3$ crystalline phase in room temperature.