• 마이크로전자및패키징학회지
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• 제7권3호
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• pp.7-11
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• 2000

공침법을 이용하여 제조한 $SrTiO_3$분말에 $CuO-SiO_2$첨가물을 혼합하여 저전압구동형 SrTiO$_3$세라믹 바리스터 소자를 제조하였다. $CuO-SiO_2$첨가물을 이용한 $SrTiO_3$세라믹 바리스터제조 공정은 복잡한 공정을 단순화시킬 수 있을 뿐만 아니라, 일반적인 소결온도보다 100~$150^{\circ}C$ 낮은 온도에서도 소결이 되었다. 이 바리스터의 비직선계수($\alpha$) 값은 첨가물 5 wt% 혼합하여 $1350^{\circ}C$에서 하소한 시편에서 8.47의 최고값을 나타냈으며, 이때의 구동전압은 7 V 이하로 낮은 구동전압을 가진 바리스터를 제조할 수 있었다.

• 한국세라믹학회지
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• 제35권10호
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• pp.1107-1112
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• 1998

We could obtan c-axis oriented $SrBi_2$$Ta_2$$O_9$ thin films on usual Pt(111)/Ti/$SiO_2$/Si(100) substrate using a r. f. magnetron sputtering technique. According to the increase of sputtering pressure from 250 to 300 mTorr the Bi content and degree of the c-a xis preferred orientation of $SrBi_2$$Ta_2$$O_9$ thin films were increased. By controlling Bi(or $Bi_2O_3$) loss from $SrBi_2$$Ta_2$$O_9$ thin films during post annealing and by inserting $Bi_2O_3$ layer in $SrBi_2$$Ta_2$$O_9$ thin films the effect of Bi content on the c-axis oriented growth of $SrBi_2$$Ta_2$$O_9$ thin films could be investigated without the effect of sputtering pressure. The degree of the c-axis preferred orientation of $SrBi_2$$Ta_2$$O_9$ thin films was increased with increasing with increasing Bi content by control of Bi(or $Bi_2O_3$) loss of $SrBi_2$$Ta_2$$O_9$ thin films. But the c-axis oriented growth of $SrBi_2$$Ta_2$$O_9$ thin films disappeared by the inserting of $Bi_2O_3$ lay-er in $SrBi_2$$Ta_2$$O_9$ thin films.

• 자원리싸이클링
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• 제2권2호
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• pp.9-15
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• 1993

본 연구에서는 광양제철소 전로 dust를 사용하여 자력산별 및 심강(분급) 실험을 통해서 산화철(magnetite)를 분리.회수하였다. 그리고 분리.회수한 산화철(magnetite)과 SrCO$_{#}$를 고상방응시켜 Sr-ferrite를 제조하고 그 자기적 특성은 조사하였으며, 이를 통하여 다음과 같은 결론을 얻었다. 1. 광양제철소 제동전로 Ep dust는 대부분 ${\alpha}$-Fe와 magnetite, wustite 등의 철산화물 상태로 존재하며 자력산별과 심강(분급)실험을 행한 결과 magnetite가 주된 구성물질인 산물을 얻을 수 있었다. 2. 전로 dust 정제를 통하여 얻어진 magnetite와 SrCO$_{4}$를 혼합한 후 하소를 행한 결과 magnetite의 산화배소과정 없이도 Sr-ferrite 생성이 가능함을 확인 하였으며, Sr-ferrite 생성 반응은 다음과 같다. I. $SrCO_3$ $+Fe_3$O$_4$+1/2(1-X)$O_2 $longrightarrow$\alpha$ $-Fe _2$$O_3$ $+SrFeO _3$\ulcorner+$CO_2$ II. $5.5\alpha$ $-Fe_2$$O_3$ $+SrFeO_3$\ulcornerlongrightarrowSrFe\ulcornerO\ulcorner+1/2(1/2-X)$O_2$ 3. 1150$^{\circ}C$에서 1시간동안 하소한 후 1250$^{\circ}C$에서 2시간 동안 산결하여 Br=3.75GK, $_{1}$Hc=1.7KOe, (B.H)$_{max}$=2.64 MGOe인 Sr-ferrite 이방성 영구자석을 제조하였다.

• 한국세라믹학회지
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• 제39권4호
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• pp.352-358
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• 2002

고체산화물 연료전지의 전해질로서 $LaGaO_3$계를 선정하여 La 대신 Sr을, Ga 대신에 Mg를 치환하여 첨가할 때 첨가량 및 소결 조건에 따라 전해질을 제조하고, 그 특성을 조사하였다. Sr과 Mg가 0.15와 0.20 mole 첨가되었을 때 Sr과 Mg가 La와Ga 자리에 동시 고용되어 (La$_{1-x}Sr_x)(Ga_{1-y}Mg_y)O_{3-\delta}$ 단일상이 나타났고, 일부 조성에서는 $LaSrGa_3O_7$ 상과 $LaSrGaO_4$ 상이 2차상으로 나타났다. $LaSrGa_3O_7$ 상은 Sr과 Mg 첨가에 의한 상이며, $LaSrGaO_4$ 상은 액상형성에 의한 것으로 나타났으며, 또한 $LaSrGaO_4$ 상은 소결온도와 Mg 첨가량이 감소함에 따라 얻어졌다. $(La_{0.8}Sr_{0.2})(Ga_{0.8}Mg_{0.2})O_{3-\delta}$ 상의 경우 소결온도를 증가함에 따라 열팽창계수는 감소하였으며, $1500^{circ}C$에서 1시간 소결한 소결체의 전기전도도는 $800^{circ}C$, 1mA에서 0.14S/cm를 나타내었다.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2001년도 춘계학술발표강연 및 논문개요집
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• pp.67-67
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• 2001

• 한국세라믹학회지
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• 제34권6호
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• pp.583-590
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• 1997

The effects of Mn2O3 and Y2O3 additives on the microstructure and dielectric properties of Sr(Zr, Ti)O3 have been investigated. Powders with Sr(Zr1-xTix)O3(0$\leq$x$\leq$0.1) composition were prepared by the conventional solid state processing from commercial TiO2 and precipitation-processed ZrO2. The powders containing sintering additives of Mn2O3 and Y2O3 were compacted and then sintered at 1,55$0^{\circ}C$ for 4 h to get>97% relative density. Mn2O3 suppressed the grain growth and Y2O3 enhanced the density of sintered body. The oxidation state of Mn ions were determined by a chemical wet method and EPR spectroscopy. Mn ions were present as Mn2+ and Mn4+ in SrZrO3, while as Mn3+ and Mn4+ in Ti-substituted Sr(Zr, Ti)O3. With the substitution of Ti, the lattice parameters of SrZrO3 decreased and its dielectric constant increased with remarkable decrease in Q value. The dielectric constant of Sr(Zr, Ti)O3 was in the range of 30 to 40, Q values 1,200~5,400 at 6 GHz and temperature coefficient of resonant frequency -67~100 ppm/K.

• 한국세라믹학회지
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• 제36권10호
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• pp.1075-1079
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• 1999

LaSrCoO3 thin films were spin-coated onto the SrTiO3(100) substrates by the chemical solution process. X-ray diffraction $\theta$-2$\theta$ scans and X-ray diffraction $\beta$ scans were used to determine the crystallinity and in -plane alignment behavior of the films. The X-ray diffraction pattern showed the film obtained by annealing at 80$0^{\circ}C$ was highly oriented. The X-ray diffraction pole-figure analysis and reciprocal-space mapping (2$\theta$-$\Delta$$\omega$ scans) of the resulting film showed that the film comprising the pseduocubic phase had an epitaxial relationship with the SriO3 substrate.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.177-180
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• 2009

Here is presented the measurement on SrO- and SrCaO-PDP operated at lower voltage. SrO- and SrCaO-PDP attain high luminous efficacy at low voltage, where the breakdown voltage is 30 % lower than that of the ordinary MgO-PDP. A one-dimensional fluid model is applied for the simulation of PDP discharge. High VUV radiation efficiency is confirmed at high ${\gamma}_i$ and both low and high $V_s$ as in the experiment. Discharge analysis in simulation also shows that the high ${\gamma}_i$ protective layer leads to high plasma density especially near the cathode electrode, being responsible for high efficiency.

• 한국세라믹학회지
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• 제34권8호
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• pp.791-796
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• 1997

The influence of Ti/Sr ratio on abnormal grain growth of Nb-doped SrTiO3 was investigated. For specimens which were isothermally sintered at temperatures above 144$0^{\circ}C$, the nucleation and growth rates of abnormal grain growth were decreased with increasing Ti/Sr ratio. But the onset time of abnormal grain growth was increased with increasing Ti/Sr ratio. The cross-section of abnormally grown grains was mostly hexagonal. When the specimens were quenched in air after they reached their setting temperatures at a heating rate of 3$^{\circ}C$/min, the onset temperature of abnormal grain growth was increased with increasing Ti/Sr ratio and the final grain size was independent of Ti/Sr ratio. The cross-section of abnormally grown grains was mostly rectangular.

• 한국세라믹학회지
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• 제21권4호
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• pp.341-348
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• 1984

$BaTiO_3$ and $SrTiO_3$ were mixed with the mole ratio of 35:65， 50:50 and 65:35 and heated at 1100~120$0^{\circ}C$ for 1~64 hours. The dielectrics of $BaTiO_3$-$SrTiO_3$ system were investigated as a function of amount of solid solution formed. The dielectric constant was increased and Curie temperature was shifted to higher temperature with increasing of heating of soaking time for the same composition and heating temperature. This can be explained by the homogeneous distribution of $Ba^{2+}$ and $Sr^{2+}$ ion in the $BaTiO_3$ system. The Curie temperature was shifted to lower temperature with increasing $SrTiO_3$ in the $BaTiO_3$-$SrTiO_3$system because of decreasing the lattice constant.