• 한국세라믹학회지
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• 제29권1호
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• pp.23-28
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• 1992

Alumina ceramics was reinforced by in-situ formation of La-${\beta}$-aluminate in ${\alpha}$-alumina matrix. The powder mixture of which composition is (100-12x)Al2O3+x(La2O3+11Al2O3) was prepared for the formation of La-${\beta}$-aluminate in ${\alpha}$-alumina matrix. The amount of La-${\beta}$-aluminate in the matrix was controlled by varing x which is number of moles. The dense composite was produced by sintering at 1600$^{\circ}C$ in air or hot-pressing at 1550$^{\circ}C$ under 30 MPa. Bending strength and fracture toughness were increased, resulting from the grain growth inhibition and the crack deflection and crack bridging mechanism when La-${\beta}$-aluminate was produced in ${\alpha}$-alumina matrix.

• 한국결정성장학회:학술대회논문집
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• 한국결정성장학회 1999년도 PROCEEDINGS OF 99 INTERNATIONAL CONFERENCE OF THE KACG AND 6TH KOREA·JAPAN EMG SYMPOSIUM (ELECTRONIC MATERIALS GROWTH SYMPOSIUM), HANYANG UNIVERSITY, SEOUL, 06월 09일 JUNE 1999
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• pp.371-387
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• 1999

La2-xSrxCuO4 single-crystalline films were prepared on bulk single crystals of Zn-doped La2CuO4 as the substrates by LPE technique using tow deferent methods. When prepared using an alumina crucible in normal electrical furnace, the La2-xSrxCuO4 films were contaminated with less than 3 at% aluminum from the alumina crucibles. Aluminum contamination either reduced or completely destroyed the superconductivity of the La2-xSrxCuO4 films. For LPE growthby modified TSFZ method using an infrared heating furnace without crucibles, the La2-xSrxCuO4 films of x=0.11 showed superconducting with Tconset 36 K, which is 10 K higher than that in the La2-xSrxCuO4 bulk single crystals.

• 한국세라믹학회지
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• 제31권6호
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• pp.617-622
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• 1994

Single crystals of misfit layered (LaS)xVS2(x 1.18) were grown using LaCl3(or I2) as a mineralizer (or transport agent) for the single crystal X-ray diffraction analysis. Procession photographs of (LaS)xVS2(x 1.18) were analyzed as the stacking structure of two kinds of LaS-and VS2-subcell. The result shows that two sublattices have common periodicities along the a*-and c*-axes, respectively, but not along the b*-axis. Sublattice dimensions of LaS and VS2 layers along b-axis were 5.67$\AA$ and 3.42$\AA$, respectively. Their ratio was 1.657 which is very close to 5/3.

• 한국세라믹학회지
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• 제37권6호
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• pp.612-616
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• 2000

The effect of Co dopant on the (La, Sr)MnO3 cathode was investigated. La2Zr2O7 and SrZrO3 were formed as the reaction products between YSZ and LSMC. The reactivity of LSMC with YSZ increased with increasing Co content. However, the cathodic polarization resistance decreased with increasing Co doping. Therefore, doping Co at Mn site in the (La, Sr)MnO3 cathode was effective on controlling the polarization resistance of the cathode. The polarization property of LSMC-YSZ composite(60 wt%: 40 wt%) cathode was better than that of LSMC single cathode.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2003년도 Proceedings of the international symposium on the fusion technology
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• pp.624-628
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• 2003

Lanthanum oxyfluoride can be synthesized by mechanochemical (MC) reaction between lanthanum oxide ($La_2O_3$) and polytetrafluoroethylene (PTFE, ($({CF_2CF_2}_n)$) in air using a planetary mill. MC reaction between the two materials induced from intensive grinding operation. The MC reaction is almost finished by 240min, and the products ground for 240min or more are composed of LaOF, amorphous $La(CO_3)F$ and amorphous carbon (C). Heating this MC reaction products at $600^{\circ}C$ enables us to eliminate amorphous C and decompose $La(CO_3)F$ into LaOF, so that pure LaOF material can be obtained as the final product. The average particle size of the final product (purified LaOF) is around few ten nanometers.

• Preventive Nutrition and Food Science
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• 제2권1호
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• pp.29-34
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• 1997

In order to determine the effectiveness of linoleic acid(LA) to inhibit carcinogens/mutagens-induced mu-tagenesis, Ames test using Salmonella typhimurium TA100 and the SOS chromotest using E. Coli PQ37, were carried out. The inhibitory effect of LA(1%) on the Ames mutagenicity test were 98%, 78%and 69% mediated by aflatoxin B₁(AFB₁), N-methyl-N'-nitro-N-nitrosoguanidine(MNNG) and 4-nitroquinoline-1-oxide(4-NQO), respectively. LA exhibited a strong antimutagenic activity aganist indirect mutagen, AFB₁whereas exhibited the same concentration of LA showed weaker inhibitory effects on direct mutagens of MNNG and 4-NQO than that AFB₁. LA also reduced the SOS responses induced by MNNG and 4-NQO significantly. This result showed a possibility that LA can be a protective agent in early step of cancinogenesis.

• 한국세라믹학회지
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• 제34권10호
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• pp.1060-1066
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• 1997

In this paper, the effects of La addition of PLZT thin film prepared by sol-gel method on the capacitor characteristics are investigated for gigabit generation DRAM applications. The addition of La on the PLZT capacitor results in a trade-off between charge storage density(Qc') and leakage current density(Jl). As La content increases, Qc' and permeability(εr) at 0V are reduced while Jl is significantly decreased. It is demonstrated that 5% La doping of PZT can substantially reduce Jl and also improve resistance to fatigue while incurring only minimal degradation of Qc'. Very low leakage current density (5×10-7 A/㎠ even at 125℃) and high charge storage density (100fC/㎛2) under VDD/2=1V conditions are achieved using 5% La doped PZT thin films for gigabit DRAM capacitor dielectrics. In addition, the fatigue and TDDB measurements indicate good reliability of the PLZT capacitors.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1997년도 추계학술대회 논문집
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• pp.48-51
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• 1997

(Pb. La)TiO$_3$ thin films were fabricated by sol-gel Processing and spin-coated on the Pt substrate. The spin-coated PLT films were sintered at 75$0^{\circ}C$ for 5min by rapid thermal ann La content dependence of the electrical properties of the PLT thin films are discussed. Wit La mole% from 20 to 36mo1e%. the dielectric constant of the PLT thin films decreased f 570. P-E hysteresis loops changed from ferroelectric to paraelectric. and the charge storage charging time decreased. The Curie Point decreased with increasing La content. The leak density also decreased and La 36mo1% species shows mood characteristics less than 10- electric field 500 (KV/cm) Because of the broad range of composition-controlled ferroelectric PLT thin films are suitable for memory application.

• 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.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 1997년도 춘계연구발표회 논문개요집
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• pp.114-115
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• 1997