• 한국세라믹학회지
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• 제50권3호
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• pp.238-243
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• 2013

We investigated the effect of Pb-metal filler added to a hybrid paste(PbO-$Bi_2O_3-B_2O_3$-ZnO glass frit and Pb-powder), for joining flip-chip sat lower temperatures than normal. The glass transition temperature was detected at $250^{\circ}C$ and the softening point occurred at $330^{\circ}C$. As the temperature increased, the specific density decreased due to the volatility of the Pb-metal and boron component in the glass. When the glass was heat-treated at $350^{\circ}C$ for 5 min, XRD results revealed a crystalline $Pb_4Bi_3B_7O_{19}$ phase that had been initiated by the addition of Pb-filler in the hybrid paste. The addition of the Pb-metal filler caused are action between the Pb-metal and glass that accelerated the formation of the liquid phase. The liquid phase that formed, promoted bonding between the flip-chip substrate sat lower temperature.

• 한국세라믹학회지
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• 제30권11호
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• pp.891-896
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• 1993

Pb(Fe1/2Nb1/2)O3 and (1-x)Pb(Fe1/2Nb1/2)O3-xPbTiO3 ceramics were prepared by the precalcination method. Their structural and dielectric properties were investigated. The amount of perovsikte phase was increased by the precalcination and the dielectric properties of ceramics were improved. Additions of PbTiO3 were found to increase the tetragonality (c/a) of crystal lattice and Tc. In the middle region of (1-x)Pb(Fe1/2Nb1/2)O3-xPbTiO3, duffuse phase transitions (DPT) were observed.

• 한국세라믹학회:학술대회논문집
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• 한국세라믹학회 2000년도 춘계총회,특별강연,심포지움,연구발표회
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• pp.27.2-27.2
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• 2000

• 자원리싸이클링
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• 제21권4호
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• pp.53-59
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• 2012

본 연구에서는 비철제련의 공정 부산물에서 얻어진 Bi-Pb-Sb 3원계 합금 용탕의 산화반응에 따른 Sb과 Pb의 제거거동에 대하여 조사하였다. $N_2+O_2$ 가스를 침지 노즐을 통해 1173 K의 합금 용탕 중에 취입하여 Sb을 산화물과 금속상의 혼합물로 분리 회수할 수 있었다. 그리고 923 K의 Bi-Pb 2원계 용탕에 $N_2+O_2$ 가스를 취입하면 Pb가 산화되어 슬래그상으로 제거될 수 있으나, Bi도 동시에 산화되어 Bi를 정제할 수 없었다.

• Bulletin of the Korean Chemical Society
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• 제17권4호
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• pp.324-330
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• 1996

We examined the formal oxidation states of Pb and Cu in the Pb2CuO4 slab of Pb2Sr2ACu3O8(A=Y1-xCaxor Nd1-xSrx) and their possible changes by oxygen incorporation in the Cu layer of the slab by performing tight-binding band electronic structure calculations on the Pb2CuO4+δ slab. Our results show that the most likely oxidation state of Pb is +2 and that of Cu is +1 for the Pb2CuO4 slab prior to oxidation. With small δ values, the oxygen incorporation occurs by the formation of such chain fragments as in YBa2Cu3O7-y along the a+b axis. The four-coordinate Cu atoms in the chain fragments are in the +3 oxidation states. For values of δ larger than 0.5, however, an additional oxygen (Oad) goes to the site along the b axis to form short Pb-Oad distances oxidizing Pb2+ to Pb4+. This change in the Pb oxidation state leads to the suppression of superconductivity due to the decrease of holes in the CuO2 layer.

• 한국세라믹학회지
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• 제25권5호
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• pp.523-531
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• 1988

The dielectric and piezoelectric properties with compositions in Pb(Ni1/3Nb2/3)O3-PbTiO3-PbZrO3-(PNN-PT-PZ)solid solution ceramics were investigated. In this study, the compsition ranges were 30 PNN 45mole%, 20 PT 50mole% and 50 PZ5mole%. As PT fraction were increased the grain size was increased and the fired density was decreased, but the changes of PNN fraction had no effect on the grain size. The Curie temperature was increased when PT and PNN fraction were increased. The displacement was increased but had a great hysteresis loss when PT fraction was increased. In morphotropic phase boundary, the maximum piezoelectric and electromechanical coupling factor were indicated. Morphotropic phase boundary(MPB) was 34 PT 36mole% in chang of compositions.

• 대한전기학회논문지
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• 제41권5호
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• pp.517-524
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• 1992

In this study, 0.10Pb(SbS11/2TSnS11/2T)OS13T-(0.90-x)PbZrOS13T (0.25 x 0.40) ceramics were fabricated by the atmospheric method. The sintering temperature and time were 1250[$^{\circ}C$] and 2[2hr], respectively. The structureal, dielectric and piezoelectric properties with composition of PbTiOS13T were studied. As the results of XRD ans SEM, the crystal structure of a specimen was rhombohedral, lattice constant and average grain size were decreased with increasing the contents of PbTiOS13T. Relative dielectric constant and Curie temperature were increased with increasing the contents of PbTiOS13T, 0.10PSS-0.40PT-0.50PZ specimen had the highest values of 904 and 265[$^{\circ}C$], respectively. In increasing of PbTiOS13T contents form 25[mol%] to 40[mol%], piezoelectric charge constant and electromechanical coupling factors were increased form 114[pC/N] to 142[pC/N], 17[%] to 24[%] and mechanical quality factor were decreased with increasing the contents of PbTiOS13T. In the 0.10PSS-0.40PT-0.50PZ specimens, those values were 14.2[kV/cm] and 9.43[x10S0-6TC/cmS02T], resectively.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2003년도 춘계학술발표강연 및 논문개요집
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• pp.211-211
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• 2003

PbTiO$_3$ 씨앗층을 이용하여 완화형 강유전체 Pb(Mg$_{1}$3/Ta$_{2}$3/)O$_3$ (PMT) 박막의 페로브스카이트 상안정화와 열처리 조건에 따른 미세구조변화, 이에 따른 전기적 특성 변화에 관하여 조사하였다. PbTiO$_3$ 박막을 스핀코팅법으로 3000 rpm에서 20초간(111) 방향으로 배향된 Pt / Ti / SiO$_2$/ Si 기판에 증착하여 안정화된 페로브스카이트 박막을 얻었다. 이렇게 제조된 PbTiO$_3$를 Buffer 층으로 사용하고 그 위에 Pb(Mg$_{1}$3/Ta$_{2}$3/)O$_3$를 박막을 Spin coating방법으로 증착한 후, 급속열처리 방법(RTA)으로 550- $650^{\circ}C$ 사이에서 열처리하였다. 제조된 박막의 열처리 온도에 따른 미세구조 변화와 결정성을 XRD, SEM, TEM으로 분석하였고 박막의 저온 강유전 특성을 RT66A를 이용하여 평가하였다. Pb(Mg$_{1}$3/Ta$_{2}$3/)O$_3$ 박막의 경우 씨앗층이 없는 경우에는 pyrochlore상이 주상이었지만 씨앗층을 사용한 경우 페로브스카이트 상이 주상임을 확인하였고 열처리 온도가 증가할수록 페로브스카이트상의 상대적 양이 증가함을 확인하였다. 미세구조와 상의 변화에 따른 전기적 특성 변화에 관하여 자세하게 논의할 것이다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1996년도 추계학술대회 논문집
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• pp.54-58
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• 1996

In this paper, the structure, dieletric and piezoelectric properties of Pb(Fe$_{\frac{1}{2}}$/Sb$_{\frac{1}{2}}$$O_3$+ Pb(Zr$_{0.52}$ Ti$_{0.48}$ )O$_3$system ceramics were investigated and the effects of donor Nb$^{+5}$ on these properties were characterized for the application of the actuator. In xPb(Fe$_{\frac{1}{2}}$Sb$_{\frac{1}{2}}$)O$_3$+ (1-x) Pb(Zr$_{0.52}$ Ti$_{0.48}$ )O$_3$system ceramics, tetragonality decreased as x and Nb$_2$O$_{5}$ wt% were increased. In 0.05Pb(Fe$_{\frac{1}{2}}$Sb$_{\frac{1}{2}$}$)O$_3$+ 0.95 Pb(Zr$_{0.52}$ Ti$_{0.48}$ )O$_3$system, grain size was smallest but showed best dielectric and piezoelectric properties. The specimen sintered at 120$0^{\circ}C$ in 0.05pb(Fe$_{\frac{1}{2}}$Sb$_{\frac{1}{2}}$ )O$_3$+ 0.95 Pb(Zr$_{0.52}$ Ti$_{0.48}$ )O$_3$+ Nb$_2$O$_{5}$ 0.6wt% exihibited best piezoeletric properties such as $K^{p}$ =64%, d$_{33}$ =490 [$\times$10$^{-12}$ C/N] and strain was 1320[$\times$10$^{-6}$ Δ$\ell$/$\ell$]at AC 6kV/cm

• 한국세라믹학회지
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• 제27권7호
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• pp.934-942
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• 1990

The quarternary system ceramics 0.5[yPb(Zn1/3Nb2/3)O3-(1-y)Pb(Ni1/3Nb2/3)O3]-0.5[xPbTiO3-(1-x)PbZrO3](PZN-PNN-PT-PZ) was fabricated by the columbite precursor method to obtain a stabilized perovskite structure and by conventional method to evaluate the efficiency of the former methd. Dielectric and piezoelectric properties were investigated and the stability of the perovskite phase was studied as a function of PZN and PT contents and firing temperature. In the samples prepared by the columbite precursor method, the pyrochlore phase, which is detrimental to both the dielectric and piezoelectric properties, was not observed in the absence of PZN, and electric properties were improved even when fabricated at low temperature. By adding PZN, some pyrochlore phase appeared and the morphotropic phase boundary of the samples shifted to more Zr-rich composition. The temperature dependence of piezoelectric constant decreased with the addition of PZN, due to the rising of the Curie point.