• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.1
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• pp.543-546
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• 2004

The melting temperature and critical temperature(Tc) of $YBa_2Cu_3O_x$ with deferent content impurities of PbO and $BaPbO_3$ were studied. When the PbO was used as addition in $YBa_2Cu_3O_x$, although the melting point could be reduced, the superconductivity(the transition width, ${\Delta}T_c$) became poor. From the XRD pattern of the sintered mixture of $YBa_2Cu_3O_x$ and PbO it was known that there is a reaction between $YBa_2Cu_3O_x$ and PbO, and the product is $BaPbO_3$. In the process of the reaction the superconducting phase of $YBa_2Cu_3O_x$ was decreased and in the sample $BaPbO_3$ became the main phase. Therefore the superconductivity was reduced. $BaPbO_3$ was chosen as the impurity for the comparative study. The single phase BaPbO3 was synthesized by the simple way from both mixtures of $BaPbO_3$ and PbO, $BaPbO_3\;and\;PbO_2$. Deferent contents of $BaPbO_3$(10%, 20%, 30%) were added in the $YBa_2Cu_3O_x$. By the phase analysis in the XRD patterns it was proved that there werenot reactions between $YBa_2Cu_3O_x$ and $BaPbO_3$. When $BaPbO_3$ was used as impurity in $YBa_2Cu_3O_x$ the superconductivity was much better than PbO as impurity in $YBa_2Cu_3O_x$. But the melting point of $YBa_2Cu_3O_x$ with $BaPbO_3$ could not be found when the temperature was lower than $1000^{\circ}C$ in the DTA measurement.

• 동굴
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• 제78호
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• pp.17-22
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• 2007

The melting temperature and critical temperature (Tc) of $YBa_2Cu_3O_x$ with deferent content impurities of PbO and $BaPbO_3$ were studied. When the PbO was used as addition in $YBa_2Cu_3O_x$, although the melting point could be reduced, the superconductivity (the transition wide, ${\Delta}T_c$) became poor. From the XRD pattern of the sintered mixture of $YBa_2Cu_3O_x$ and PbO it was known that there is a reaction between $YBa_2Cu_3O_x$ and PbO, and the product is $BaPbO_3$. In the process of the reaction the superconducting phase of $YBa_2Cu_3O_x$ was decreased and in the sample $BaPbO_3$ became the main phase. Therefore the superconductivity was reduced. $BaPbO_3$ was chosen as the impurity for the comparative study. The single phase $BaPbO_3$ was synthesized by the simple way from both mixtures of $BaCO_3$ and PbO, $BaCO_3$ and $PbO_2$. Deferent contents of $BaPbO_3$ (10%, 20%, 30%) were added in the $YBa_2Cu_3O_x$. By the phase analysis in the XRD patterns it was proved that there were not reactions between $YBa_2Cu_3O_x$ and $BaPbO_3$. When $BaPbO_3$ was used as impurity in $YBa_2Cu_3O_x$ the superconductivity was much better than PbO as impurity in $YBa_2Cu_3O_x$. But the melting point of $YBa_2Cu_3O_x$ with $BaPbO_3$ could not be found when the temperature was lower than $1000^{\circ}C$ in the DTA measurement.

• 공업화학
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• 제4권2호
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• pp.273-283
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• 1993

티타늄마드래스 소지에 $PbO_2$를 전착하는 과정에서 전해액에 여러 가지 산과 유기물질의 첨가는 $PbO_2$전착층의 물성에 큰 영향을 준다. XRD결과 ${\beta}-PbO_2$가 산성 전해액에서 전착되는 것을 확인하였다. 본 실험에서 사용된 첨가제 중 전해액에 sodium lauryl sulfate를 첨가할때 산소과전압이 가장 높은 $PbO_2$가 전착되었으며 polyethylene glycol을 첨가할때는 염소과전압이 가장 낮은 $PbO_2$가 전착되었다. $PbO_2$의 산소과전압과 염소과전압은 $PbO_2$를 전착하는 동안 행하는 교반에 크게 의존한다. SEM결과 전착하는 동안 교반하지 않고 전착한 $PbO_2$결정이 교반하여 전착한 $PbO_2$보다 더욱 크다는 것을 관찰하였다. 또한 산성전해액에서 $PbO_2$를 전착할 경우, $PbO_2$결정 크기가 클수록 산소과전압은 커지며 $PbO_2$결정 크기가 작을수록 염소과전압은 낮아졌다. $HClO_4$의 존재하에서 $PbO_2$를 전착할 경우 560g/1 $Pb(NO_3)_2$, $65{\sim}70^{\circ}C$, pH>1에서 최적의 전착전류효율을 나타내었다.

• 한국세라믹학회지
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• 제34권3호
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• pp.281-288
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• 1997

유전율이 높고 온도안정성이 우수하다고 알려져 있는 40Pb(Mg1/3Nb2/3)O3-30PbTiO3-30Pb(Mg1/2W1/2)O3계 세라믹스에 소결온도를 낮추기 위하여 저온에서 액상을 형성하는 91PbO-9WO3를 과잉첨가하여 소결성, 미세구조 및 유전성의 변화에 대하여 조사하였다. 91PbO-9WO3의 첨가량이 증가함에 따라 소결온도가 저하하였으며 6 mol%첨가시는 875$^{\circ}C$에서 소결이 가능하였다. 유전율은 기본조성에서 16,400이었고, 첨가제가 1 mol% 과잉첨가된 경우 18,500으로 최대값을 나타냈으며 이후 첨가량이 증가함에 따라 감소하였다. 첨가제의 첨가량이 2~4mol%인 시편의 온도에 따른 유전율 변화곡선에서 double peak maxima가 나타났으나, 첨가량이 5 mol% 이상인 시편에서는 입계에 텅스텐을 많이 포함하고 있는 결정상이 생성되었고 double peak maxima는 나타나지 않았다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2004년도 SMICS 2004 International Symposium on Maritime and Communication Sciences
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• pp.57-59
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• 2004

The melting temperature and critical temperature (Tc) of YBa$_2$Cu$_3$Ox with deferent content impurities of PbO and BaPbO$_3$ were studied. When the PbO was used as addition in YBa$_2$Cu$_3$Ox, although the melting point could be reduced, the superconductivity (the transition wide, ΔTc) became poor. From the XRD pattern of the sintered mixture of YBa$_2$Cu$_3$Ox and PbO it was known that there is a reaction between YBa$_2$Cu$_3$Ox and PbO, and the product is BaPbO$_3$. In the process of the reaction the superconducting phase of YBa$_2$Cu$_3$Ox was decreased and in the sample BaPbO$_3$became the main phase. Therefore the superconductivity was reduced. BaPbO$_3$was chosen as the impurity for the comparative study. The single phase BaPbO$_3$was synthesized by the simple way from both mixtures of BaPbO$_3$and PbO, BaPbO$_3$and PbO$_2$. Deferent contents of BaPbO$_3$(10%, 20%, 30%) were added in the YBa$_2$Cu$_3$Ox. By the phase analysis in the XRD patterns it was proved that there were not reactions between YBa$_2$Cu$_3$Ox and BaPbO$_3$. When BaPbO$_3$was used as impurity in YBa$_2$Cu$_3$Ox the superconductivity was much better than PbO as impurity in YBa$_2$Cu$_3$Ox But the melting point of YBa$_2$Cu$_3$Ox with BaPbO$_3$could not be found when the temperature was lower than 1000 $^{\circ}C$ in the DTA measurement.

• 한국세라믹학회지
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• 제11권3호
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• pp.19-26
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• 1974

Mechanical properties of the system PbO-B2O3-V2O5 low melting glass during crystallization by heat-treatment were investigated. Wettability of the system PbO-B2O3-V2O5 was excellent and appropriate for commercial sealing as a low melting solder glass. Crystals, during heat-treated at 30$0^{\circ}C$ of the system PbO-B2O3-V2O5 were $\beta$-4PbO.B2O3, 5PbO.4B2O3, and Pb2V2O7 mainly. The percent of crystallinity was 82$\pm$5%. Mechanical properties of the system PbO-B2O3-V2O5 were influenced not only by the differences of density and coefficient of thermal expansion and the stress induced from the difference in the density and coefficient of thermal expansion between glass phase and crystals but also crystallization conditions.

• 한국세라믹학회지
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• 제22권2호
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• pp.17-24
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• 1985

In the composition of $Pb(Mg_{0.15} W_{0.15})Ti_{0.35}-Zr_{0.35}O_3$ the effect of particle size on PbO vaporization were measured, . The initial step of discontinuous vaporization of unreated PbO during the calcining process was depended on the particle size. All additives $La_2O_3Nb_2O_5$ and $Al_2O_3$ inhibited the grain growth of the composition $Pb(Mg_{0.15} W_{0.15})Ti_{0.35}-Zr_{0.35}O_3$ +2wt% excess PbO. The dielectric and piezoelectric properties of the composition $Pb(Mg_{0.15} W_{0.15})Ti_{0.35}-Zr_{0.35}O_3$ were improved by the addition of 2wt% excess PbO and proper additive. The electromechanical planar coupling factor of 0.65 and mechnical quality factor of 390 could be obtained by adding 5wt% $Nb_2O_5$ to the composition 2wt% excess PbO+$Pb(Mg_{0.15} W_{0.15})Ti_{0.35}-Zr_{0.35}O_3$.

• 공업화학
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• 제7권6호
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• pp.1105-1114
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• 1996

${\alpha}-PbO_2/IrO_2-TiO_2/Ti$지지체상에 sodium lauryl sulfate 및 $TiO_2$분말을 첨가한 질산납 전해액에서 전착한 ${\beta}-PbO_2$층의 특성 및 성능을 XRD, SEM, cyclic voltammograms, 매크로전해를 이용하여 검토하였다. XRD분석결과 sodium lauryl sulfate 및 $TiO_2$분말의 존재하에 ${\alpha}-PbO_2/IrO_2-TiO_2/Ti$ 지지체 위에 전착한 ${\beta}-PbO_2$층은 순수한 ${\beta}-PbO_2$층과 마찬가지로 정방정계구조를 나타냈다. SEM결과 sodium lauryl sulfate는 전착층의 결정입자크기를 작게 하는 경향을 보여준다. sodium lauryl sulfate 및 $TiO_2$분말의 존재하에 전착한 ${\beta}-PbO_2$전극은 KOH 및 $HClO_4$지지전해질에서 양극산화에 대한 산소과전압과 내구성을 크게 향상시켰다. 티타늄마드래스에 전착시킨 ${\beta}-PbO_2$전극을 이용하여 과염소산용액으로부터 오존 발생에 대한 전극성능과 내구성을 검토하였다. $HClO_4$지지전해질에 sodium lauryl sulfate와 $TiO_2$분말을 첨가하여 ${\alpha}-PbO_2/IrO_2-TiO_2/Ti$ 마드래스상에 전착한 ${\beta}-PbO_2$전극이 가장 높은 전류효율과 내구성을 가짐을 확인하였다.

• 한국재료학회지
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• 제4권4호
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• pp.472-476
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• 1994

질산납으로부터 침전법으로 제조된 PbO-전구체의 상변태를 열분석, X-선 회절, 적외선 흡수 및 Raman분광 분석 등을 통하여 조사하였다. 질산납 수용액으로부터 $45^{\circ}C$, pH 9.0의 반응조건에서 PhO-전구체를 제조하였다. 침전물은 hydrous lead oxynitrate와 lead hydroxynitrate의 혼합체이었다. $560^{\circ}C$까지 열처리온도가 증가함에 따라 전구체는 $3Pb(NO_{3})_{2}$ㆍ7PbO를 거쳐 $Pb(NO_{3})_{2}$ㆍ5PbO로 된 후에 PbO(litharge)로 변화되었으며, $560^{\circ}C$이상에서 최종적으로 massicot형의 PbO로 변태되었다.

• 한국세라믹학회지
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• 제37권7호
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• pp.673-680
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• 2000

The effect of excess PbO(0, 1, 2, 4, and 8 mol%) on grain growth and densification of (65)Pb(Mg1/3Nb2/3)O3-(35)PbTiO3 [mol%] ceramics has been investigaetd. With increasing the amount of excess PbO and sintering time, densities of sintered samples decreased gradually. The samples containing less than 1 mol% of PbO showed normal grain growth behavior, however abnormal grain growth was observed to occur in the samples with more than 2 mol% of PbO. In the samples with more than 2 mol% of PbO, the number of abnormal grains decreased and thus the average grain size became smaller with increasing the amount of excess PbO. These results demonstrated that the abnormal grain growth started to occur when a critical amount of excess PbO was added to a (65)Pb(Mg1/3Nb2/3)O3-(35)PbTiO3 sample. Since PMN-PT grains in a liquid matrix were angular, the observed abnormal grain growth was explained to proceed through the two dimensional nucleation process.