• Journal of the Korean Ceramic Society
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• v.24 no.5
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• pp.477-483
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• 1987

Cr2O3 doped Pb(Zr0.525 Ti0.475)O3 piezoelectric ceramics were prepared from reagent grade oxide mixture, PbO, ZrO2, TiO2 and Cr2O3. Piezoelectric and aging properties of specimens were measured for various additions of Cr2O3. Generally, it has been known that aging rate decreased with Cr2O3 addition by stabilizing the domain wall. But hysteresis loops showed that the domain destabilization was occurred at high electric field (larger than 10KV/cm). In smaller additions of Cr2O3 (0-0.2mol%), aging rate increased and microcracks were created with increasing poling filed due to increasing internal stress. In larger additions of Cr2O3(0.4∼0.6mol%), aging rate decreased with increasing poling field.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.55-58
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• 2003

[ $YBa_2Cu_3Ox$ ](YBCO) oxide superconductor was prepared by sol-gel method to improve its superconducting properties, and it was made to be a fine powder, which has the same property of solid state reacted powder. $BaPbO_3$ was synthesized with $BaCO_3$, BaO, PbO, and $PbO_2$ and analyzed by XRD. YBCO superconductor was prepared by use of sol-gelled YBCO powder and additive $BaPbO_3$ and its critical temperature and transition temperature were shown as 91.9 K, 3.7 K respectively in case 20 wt.% $BaPbO_3$ was added to pure sol-gelled YBCO powder.

• Journal of the Korean Ceramic Society
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• v.33 no.4
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• pp.391-398
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• 1996

In order to understand the electrostrictive behavior of Pb(Mg1/3Nb2/3)O3-PbTiO3(PMN-PT) solid solutions the dielectric constants and the electric-field-induced strains in (1-x)PMN-xPT (x=0.0-0.4) were investigated in the temperature range -5$0^{\circ}C$-20$0^{\circ}C$. Powder of (1-x)Pb(Mg2/3Nb2/3)O3-xPbTiO3 (x=0.0, 0.1, 0.2, 0.3, 0.35, and 0.4) were prepared from the oxide forms of Pb, Mg, Nb and Ti via a columbite precursor method As the amount of PbTiO3 increases the temperature of maximum dielectric constant(T$\varepsilon$max) increases and the phase transition become less diffusive. The strain maximum occurs only when the diffuse phase transition occurs from rhombohedral to cubic or rhombohedral to tetragonal as in x=0.1-0.35 The strains monotonically decrease with temperature in the materials in which phase transition occurs from tetragonal to cubic as in x=0.4.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1988.10a
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• pp.50-53
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• 1988

Lead titanate powders were prepared by mixed-oxide and sol-gel method. O-3 composites were prepared with these powders using Eccogel polymer. According to the volume percent of the PbTiO$_3$ powders, dielectric, piezoelectric properties and poling conditions were investigated. Relative dielectric constants were exponentially increased with volume percent of PbTiO$_3$. Piezoelectric strain coefficients (d$_{33}$ ) were increased with volume percent of PbTiO$_3$. Figure of merit (d$_{h}$.g$_{h}$) for the O-3 composites prepared by the mixed-oxide and sol-gel method were 2728(x10$^{-15}$ $m^2$/N) and 3100(x10$^{-15}$ $m^2$/N) at 70 volume percent of PbTiO$_3$, respectively.ely.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.338-339
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• 2005

본 연구에서는 $Fe_2O_3$를 첨가한 $Pb(Ni_{1/3}Nb_{2/3})O_3-Pb(Zr_xTi_{1-x})O_3$ 세라믹스에서 Zr/Ti 비 변화에 따른 소결 및 압전, 유전특성을 조사하였다. $0.4Pb(Ni_{1/3}Nb_{2/3})O_3-0.6Pb(Zr_xTi_{1-x})O_3$+0.25Wt% $Fe_2O_3$ 계에서 Zr/(Ti+Zr)비(x)를 0.39에서 0.42까지 변화시킨 조성을 1100 - $1250^{\circ}C$ 온도에서 2시간 소결하여 이의 결정구조 및 미세조직을 분석하였고, 압전, 유전 특성 및 RAINBOW 액츄에이터로의 응용을 조사하였다. $1150^{\circ}C$에서 소결한 0.405 조성(x)에서 유전상수(${\varepsilon}r$) = 4669, 전기기계결합계수(kp) = 0.75, 압전상수($d_{33}$) = 810 pC/N의 우수한 특성 값을 나타내었으며, 닥터블레이드법에 의해 RAINBOW 액츄에이터를 제작하여 변위특성을 조사하였다.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.7 no.4
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• pp.589-598
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• 1997

The effects of PT/PZ ratio variations in a modified PZT system on crystal structure and electrical properties were studied. $0.05Pb(Sn_{0.5}Sb_{0.5})O_3＋xPbTiO_3＋yPbZrO_3$＋0.4Wt% $MnO_2$(＝0.55PSS＋0.11PT＋0.84PZ＋0.4wt%$MnO_2$ ; x＋y=0.95) systems with variations of PT/PZ from 0.50/0.45 to 0.l1/0.84 were sintered at $1250^{\circ}C$ for 2 hr, and then sintering density, crystal structure, dielctric, piezoelectric, pyroelectic and voltage responsity to infrared were investigated. Sintering density was increased from 7.52g/$\textrm {cm}^3$ to 7.82g/$\textrm {cm}^3$ with increasing PZ content. Dielectric constants at 1 KHz were decreased from 1147 to 193 with variation of PT/PZ from 0.50/0.45 to 0.l1/0.84 after poling of $4 KV_{DC}$/mm at $140^{\circ}C$ for 20 minutes. All Dielectric losses at 1 KHz were less than 1 % in all specimens. $K_{p}$ was increased near to 1 of PT/PZ, and maximun value of 48.2 % was .at 0.45/0.50. Pyroelectric coefficient of PT/PZ with 0.l1/0.84 was maximun value, 0.0541 C/$\m^2$K, and voltage responsity to infrared was 1.5 V.

• The Korean Journal of Ceramics
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• v.6 no.4
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• pp.396-400
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• 2000

Dielectric and piezoelectric properties of Pb$_0.9$La$_0.1$TiO$_3$ ceramics were investigated as a function of grain size. Sintering atmosphere was controlled with changing the kind of atmospheric powder and its amount. It was confirmed that dielectric and piezoelectric of Pb$_0.9$La$_0.1$TiO$_3$ were strongly influenced by the sintering atmosphere. Relative dielectric constant of Pb$_0.9$La$_0.1$TiO$_3$ which was sintered in PbO-deficient atmosphere made by Pb$_0.9$La$_0.1$TiO$_3$ powder, increased with the grain size. However, the dielectric constant of the samples sintered in the PbO-sufficient atmosphere made by PbZrO$_3$ powder was slightly decreased with the grain size. Piezoelectric d$_33$ constant of Pb$_0.9$La$_0.1$TiO$_3$ also showed a different trend, depending on the sintering atmosphere. It was almost constant in the range of grain size of 1.3~2.3 $\mu$m when the samples were sintered in the PbO-sufficient atmosphere, while it intensively decreased with the grain size in the case of the PbO-deficient condition.

• Proceedings of the Korean Ceranic Society Conference
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• 2002.10a
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• pp.111.2-111
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• 2002

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.2 no.2
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• pp.40-52
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• 1992

$PbTi0_3$ thin films were deposited at $550^{\circ}C$ by MOCVD method using titanium-iso-propoxide [$Ti(OC_3H_7)_4$] and tetra-ethyl-lead $[Pb(C_2H_5)_4]$as starting materials. In the present study, Ar and $O_2$were used as a carrier gas and a reaction gas, respectively, and the change of thickness and refractive index, Xray diffraction analysis, and CV characteristic measurements of the films were systematically investigated. As a result of CV characteristic analysis of the annealed $PbTiO_3$ thin films, it is assumed that the films interact with Si substrate at the interface, and X-ray diffraction patterns of the films show characteristic peaks for $PbTiO_3$ With increasing the annealing temperature and time, the thickness of the films tends to decrease but their refractive index increases.

• Journal of the Korea Institute of Military Science and Technology
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• v.8 no.4 s.23
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• pp.85-90
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• 2005

We report the phase transition temperatures of the $PbZrO_3$ perovskite nanotubes made by sol-gel template synthesis. The lead zirconate($PbZrO{_3}$) nanotubes were prepared with a chelate sol-gel of zirconium tetrabutoxide($Zr(OBu){_4}$) and leadacetate($Pb(OAc){_2}-3H_2O$). $Whatman^(r)$ anodisc membranes, with a 200nm pore size, served as the template. After removing the template in the 6M-NaOH solution, the $PbZrO{_3}$ nanotubes so far have shown an anomalous transition temperature, $123.6^{\circ}C$ as measured by DSC with a small particle size, 15.4nm determined by X-ray analysis with the aid of Scherrer's equation.