• Journal of the Korean Crystal Growth and Crystal Technology
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• v.13 no.2
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• pp.63-67
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• 2003

Synthesis of $PbLaTiO_{3}$ : Mn powders containing La and Mn was carried out using $PbO,\;TiO_{2},\;La_{2}O_{3}\;and\;MnO_{2}$ as starting materials by hydrothermal method. In the synthesis of single phase $PbLaTiO_{3}$ : Mn powder containing La and Mn, the optimal x value corresponding to La substitution was 0.01 which corresponds to $0.99(Pb_{1-x}La_{2x/3}TiO_{3})+0.01MnO_{2}$. The optimal conditions for the preparation of the powder synthesis were 8 M-KOH solvent of hydrothermal solvent, $270^{\circ}C$ of reaction temperature and 24 hrs of run time. It was found that the synthesized powders had spherical morphology with average particle size of 70 nm and specific surface area of $5.5\;m^{2}/g$.

• Journal of the Korean Ceramic Society
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• v.17 no.2
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• pp.80-88
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• 1980

The sintering phenomena and piezoelectric properties of PZT ceramics of composition $Pb(Zr_{0.54} Ti_{0.46})O_3$ were investigated when a small quantity of $La_2O_3$ , $LaMnO_3$, $LaCrO_3$ were added. The unwanted chemical composition change in PZT during sinterin porces du to PbO evaporation poses a severe problem in PZt manufacturinig. It is observed tat an addition of small amount of $LaMnO_3$ to PZT markedly decreases the evaporation of PbO during sintering . The green compact of (1-x) PZT.xLaMnO3(x=0.02~0.10) could be sintered of under O2 atmosphere alone with no significant loss of PbO. The planar coupling factor kp of the sintered $0.98Pb(Zr_{0.54} Ti_{0.46})O_{3.0.02}LaMnO}3$ is similar to that of commercial PZT 6A. Microstructure investigation shows that part of sintering process of $Pb(Zr, Ti)O_3$.$LaMnO_3$ system progresses via liquid phase sintering. It is believed that the evaporation of PbO in PZT sintering is restricted by the addition of $LaMnO_3$ due to the above phenomena. Furthermore the solid solution of $LaMnO_3$ in PZT causes diffuses phase transition.

• Journal of the Korean Ceramic Society
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• v.32 no.3
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• pp.378-384
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• 1995

Effects of $La_2O_3$, $MnO_2$ on the dielectric and piezoelectric properties of $0.02Pb(Y_{2/3}W_{1/3}O_3-0.98Pb(Zr_{0.52}Ti_{0.48})O_3$ system were investigated. The addition of La2O3 to the system enhanced electromechanical coupling factor (kp), piezoelectric constant (d33), but hardly changed mechanical quality factor (Qm). On the other hand, the addition of $MnO_2$ increased Qm significantly, but did not degrade kp and d33 so much. The piezoelectric properties of $0.02Pb(Y_{2/3}W_{1/3}O_3-0.98Pb(Zr_{0.52}Ti_{0.48})O_3$ containing 0.1wt% $La_2O_3$, 0.4wt% $MnO_2$ were very good and kp, d33, Qm were 55%, 350$\times$10-12C/N, 780, respectively. The size of the grains was proportional to the change of c/a (tetragonality) ratio caused by the addition of $La_2O_3$ and $MnO_2$, and dielectric, piezoelectric properties were sensitive to the amountof pyrochrole phase.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.11 no.6
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• pp.246-251
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• 2001

The $[(Pb_{1-x}$La_{2x/3})TiO_3$, X=0.2] powder was synthesized by the hydrothermal method, and their sintering and dielectric properties according to Mn additive were examined. The relative density of sintered PLT specimen at $1150^{\circ}C$ for 5 hrs with Mn 0.02 mol% additive was 96.7%. The dielectric properties of sintered PLT specimen were changed by content of Mn and increacement of sintering temperature. Dissipation factor was improved by increasing of measuring temperature. Curie temperature of sintered PLT specimens was decreased with increasing of Mn additive.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.442-445
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• 2001

In this study, microstructural and dielectric properties of $Pb_{0.83}(La_{0.2}Ce_{0.8})_{0.08}TiO_3$(PCT) ceramics as a function of $MnO_2$ addition were investigated for 30MHz ceramic resonator application. Grain size was gradually increased according to the increase of $MnO_2$ addition amount and showed the highest value of $1.502{\mu}m$ at the 0.9wt% $MnO_2$. Moreover, density showed the highest value of $7.582 g/cm^3$ at the 0.7wt% $MnO_2$.All the composition ceramics,curie temperature was nearly constant around $330^{\circ}C$

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.194-197
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• 1991

In this study, $(Pb_{0.99}La_{0.01})[(Sb_{1/2}Sn_{1/2})_{0.10}Ti_{0.25}Zr_{0.65}]O_3$, added $MnO_2$ (0-0.30[mol%]) ceramics were fabricated by the mixed oxide method. The sintering temperature and time were $1250[^{\circ}C]$, 2[hr], respectively. In the $(Pb_{0.99}La_{0.01})[(Sb_{1/2}Sn_{1/2})_{0.10}Ti_{0.25}Zr_{0.65}]O_3$ added $MnO_2$ (0.24[mol%]) specimens, relative dielectric constant and dielectric loss were minimum values 3.52, 0.003, respectively, and Curie temperature were highest values $256[^{\circ}C]$. Pyroelectric coefficient and voltage responsivity of the $(Pb_{0.99}La_{0.01})[(Sb_{1/2}Sn_{1/2})_{0.10}Ti_{0.25}Zr_{0.65}]O_3$, and added $MnO_2$ (0.24[mol%]) specimen were good values, $6.73{\times}10^{-8}[C/cm^2K],\;125[v/W]$, respectively. Figure of merit of pyroelectric current, voltage and detectivity of the specimen, $(Pb_{0.99}La_{0.01})[(Sb_{1/2}Sn_{1/2})_{0.10}Ti_{0.25}Zr_{0.65}]O_3$ added $MnO_2$ (0.24[mol%]) were good values $2.714{\times}10^{-8}[Ccm/J],\;7.706{\times}10^{-11}[Ccm/J],\;2.640{\times}10^{-8}[Ccm/J]$, respectively. Voltage responsivity of the $(Pb_{0.99}La_{0.01})[(Sb_{1/2}Sn_{1/2})_{0.10}Ti_{0.25}Zr_{0.65}]O_3$ added $MnO_2$ (0.24[mol%]) specimens were decreased with increasing the chopper frequency.

• Proceedings of the Materials Research Society of Korea Conference
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• 2001.05a
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• pp.53-53
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• 2001

• Journal of the Korean Ceramic Society
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• v.33 no.8
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• pp.883-888
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• 1996

• Journal of the Korean Ceramic Society
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• v.36 no.11
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• pp.1183-1188
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• 1999

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.684-688
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• 2001

The structural, piezoelectric and dynamic range characteristics of modified PbTi $O_3$ceramics were investigated as a function of Mn $O_2$addition. With the increase of Mn $O_2$addition, Curie temperature was decreased. As the increase of Mn $O_2$addition, mechanical quality factor ( $Q_{mt3}$) in the third over tone thickness mode was increased. Dynamic range in the third over tone thickness mode was also increased with the increase of Mn $O_2$addition. The composition ceramics added to 0.075wt% Mn $O_2$showed the best properties for SMD type resonator using third over tone thickness vibration in terms of high Curie temperature more than 31$0^{\circ}C$ and dynamic range of 49.38dB.B.