• Journal of the Korean Crystal Growth and Crystal Technology
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• v.7 no.4
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• pp.555-559
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• 1997

Lead scandium niobate $Pb(Sc_{1/2}Nb_{1/2})O_3$ powders were prepared by the sol-gel method using lead acetate, scandium acetate, and niobium isopropoxide as precursors. Crystallization behavior and phase formation were investigated for gel-derived powders. After the calcination at $700^{\circ}C$ for 1 hr, $Pb(Sc_{1/2}Nb_{1/2})O_3$ powder with the purity of 97% was formed and the average particle size of powder was below 0.2 $\mu \textrm{m}$.

• Applied Science and Convergence Technology
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• v.25 no.4
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• pp.77-80
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• 2016

The $PbSc_{1/2}Nb_{1/2}O_3$ ceramics at a relatively low temperature of $1300^{\circ}C$ was successful synthesized. Solid state reaction of two-step process is not necessary. The dielectric constant, dielectric loss and admittance of ceramic samples were determined. The pyroelectric characteristics are in good agreement with the dielectric properties. Ferroelectric properties of well-formed the $PbSc_{1/2}Nb_{1/2}O_3$ ceramics are in agreement with broad distribution of relaxation phenomenon. Relatively strong frequency dependent of dielectric constant is observed at about $110^{\circ}C$. The distinct thermal hysteresis was observed in the measurement of the dielectric constant and dielectric loss. The critical exponents of during cooling and heating measurements in the $PbSc_{1/2}Nb_{1/2}O_3$ ceramics were 1.14 and 1.59 at 1 kHz, respectively.

• Journal of the Korean Ceramic Society
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• v.36 no.12
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• pp.1287-1295
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• 1999

• 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

• Proceedings of the Korean Ceranic Society Conference
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• 2000.10a
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• pp.44.2-44
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• 2000

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.7 no.3
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• pp.400-405
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• 1997

Lead scandium niobate powders were prepared by a molten salt synthesis method using KCl as a flux. Variations in phase formation and particle morphology were investigated for the temperature range $700^{\circ}C$ to $850^{\circ}C$. Pure $Pb(Sc_{1/2}Nb_{1/2})O_3$ perovskite phase was formed at $850^{\circ}C$ after 2hrs and the average particle size of powder was below 0.5 $\mu\textrm{m}$. The results are discussed with respect to DTA, X-ray diffraction, and microstructural characterization data.

• Journal of the Korean Ceramic Society
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• v.37 no.1
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• pp.63-69
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• 2000

Electrically-induced strain(S) and polarization(P) for Pb(Sc1/2Nb1/2)O3-PbTiO3(1-x)PSN-xPT) crystalline solutions were studied. From the compositional dependence of S and P we could observe two maximum values at x=0.10 and x=0.425. It is considered that PSNT10(x=0.10) composition is the structural phase boundary to indicate the variable order-disorder[VOD] region. PSNT(x=0.425) composition is the morphotropic phase boundary[MPB] to indicate the rhombohedral to tetragonal phase transition. Higher S (0.437%) and P (0.3974$\mu$C/$\textrm{cm}^2$) values were attained by the La substitution (5 wt%) at Pb site in the MPB composition of 57.5PSN-42.5PT.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.1809-1811
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• 2000

High power piezoelectric materials are presently being extensively developed for applications such as ultrasonic motors and piezoelectric transformer In this study, the piezoelectric and dielectric properties of $MnO_2$ doped $0.36Pb(Sc_{1/2}Nb_{1/2})O_{3}-0.25Pb(Ni_{1/3}Nb_{2/3})O_{3}-0.39PbTiO_3$ (hereafter PSNNT), which is the morphotropic phase boundary composition of the PSN-PNN-PT system were investigated. $MnO_2$-addition into the $0.36Pb(Sc_{1/2}Nb_{1/2})O_{3}-0.25Pb(Ni_{1/3}Nb_{2/3})O_{3}-0.39PbTiO_3$ composition increases the piezoelectric coefficient up to $k_{p}{\fallingdotseq}$55.6[%] and $Q_{m}{\fallingdotseq}$252. Moreover, $MnO_2$ addition makes tetragonal phase more stable with respect to rhombohedral phase.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.2
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• pp.124-129
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• 2007

Dielectric and piezoelectric properties of $0.57Pb(Sc_{1/2}Nb_{1/2})O_{3}-0.43PbTiO_{3}$, which is the morphotropic phase boundary composition for the PSN-PT system, were investigated as a function of $Fe_{2}O_{3},\;Nb_{2}O_{5}\;and\;MnO_{2}$ addition 0 wt% to 0.9 wt%. The maximum dielectric constant of ${\varepsilon}_{33}/{\varepsilon}_{o}=2054$ and the minimum dielectric loss of $tan{\delta}=0.37\;%$ at room temperature were obtained at 0.1 wt% of $Fe_{2}O_{3}$ and 0.5 wt% of $MnO_{2}$ addition, respectively. With addition of 0.5 wt% $Nb_{2}O_{5}$ and $0.5\;wt%\;MnO_{2}$, the electromechanical coupling factor $k_{p}$ and mecanical quality factor $Q_{m}$ were significantly increased, respectively. The maximum electromechanical coupling factor $k_{p}=61.5\;%$ was obtained by addition of $Nb_{2}O_{5}$ and high mechanical quality factor $Q_{m}=919$ was obtained by addition of $MnO_{2}$. The $Q_{m}(=919)$ value is 3.3 times larger than that of non-doped 0.57PSN-0.43PT ceramics.

• Proceedings of the KIEE Conference
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• 1999.07d
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• pp.1713-1716
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• 1999

PSN-PT 2성분계 압전세라믹스의 상도로부터 유전적, 압전적 특성이 양호한 MPB (Morphotropic phase boundary)부근의 조성을 선택하여 도너 도펀트인 $Nb_2O_5$와 억셉터 도펀트인 $Fe_2O_3$를 각각 $0{\sim}9wt%$ 첨가하여 유전특성을 비교, 연구해보았다 시편모두 $1250^{\circ}C$이상에서 이론밀도의 96%이상의 값을 얻을 수 있었고 상온, 1kHz에서 $Fe_2O_3$의 경우 0.1wt% 첨가된 시편에서 ${\varepsilon}_r=2054$의 최대 비유전율이 나타났으며, 0.7wt% 첨가된 시편에서는 $tan{\delta}$=0.49%의 최소 유전 손실값을 얻었다. 도펀트가 첨가됨에 따라 ${\varepsilon}_r$는 점점 감소하는 경향을 보였으며 큐리온도 Tc는 $Fe_2O_3$의 경우에서 더 큰 값이 나타났다. $Nb_2O_5$의 경우 도펀트의 증가에 따라 완만한 Relaxor의 형태로 나타났다.