• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.434-437
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• 2001

In this study piezoelectric and dielectric properties of $Pb(Mn_{1/3}Nb_{2/3})O_{3}-Pb(Zr,Ti)O_{3}$ ceramics were investigated with $Pb(Ni_{1/3}Nb_{2/3})O_{3}$ substitution. As the $Pb(Ni_{1/3}Nb_{2/3})O_{3}$ substitution was increased, dielectric constant and electromechanical coupling factor (kp) were increased while mechanical quality factor decreased.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.438-441
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• 2001

In this study,microstructure and piezoelectric characteristics of PNW-PMN-PZT ceramics manufactured using attrition milling method were investigated. Sintering temperature of the ceramics was varied from $1180^{\circ}C$ to $1240^{\circ}C$.With increasing sintering temperature, dielectric constant was increased. In the specimen sintered at $1120^{\circ}C$,electromechanical coupling factor(Kp) and density showed the maxinum values of 0.546 and $7.78(g/cm^{3})$, respectively. In the specimen sintered at $1160^{\circ}C$,mechanical quality factor(Qm) also showed the maxinum value of 1,943.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.11a
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• pp.178-180
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• 2005

In this study, in order to develop multilayer low temperature sintering piezoelectric transformer, $Pb_{0.97}Sr_{0.03}[(Mn_{1/3}Nb_{2/3})x(Zr_{0.48}Ti_{0.52})_{1-x}O_3]+$ 0.25wt% $CeO_2$+0.3 wt% $Nb_2O_5$ system ceramics were fabricated using $Li_2CO_3-CaCO_3$ and CuO as sintering aids and their piezoelectric and dielectric characteristics were investigated with the amount of PMN substitution. With increasing PMN substitution, electromechanical coupling factor kp and dielectric constant were increased.

• Journal of the Korean Ceramic Society
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• v.26 no.6
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• pp.802-810
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• 1989

The temperature dependence of piezoelectric strain constant and the electric field induced strain are investigated as a function of PT in 0.5[xPT-(1-x)PZ]-0.5PNN ceramics. The piezoelectric strain constant d31 has the highest value(360$\times$10-12m/V) at PT=0.68. The temperature dependence of d31 is improved as Curie temperature of sample is increased, and the electric field dependence of induced strain is decreased with the coercive field increased. This ceramic system shows both piezoelectric effect and electrostrictive effect under the applied electric field. The piezoelectric of tetragonal phase is higher than that of rhombohedral phase, and the magnitude of electrostrictive constant is appeared in the order of morphotropic, rhombohedral and tetragonal phase. The piezoelectric strain constant with applied field must be considered theelectrostrictive effect due to 90$^{\circ}$domain wall displacements, and the displacement of bimorph type actuator agrees with the calulated value well.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.11a
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• pp.322-325
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• 2002

In this study, dielectric and piezoelectric properties of PSN-PZT Ceramic were investigated as a function of PNW substitution. With the increase of PNW substitution, teragonality, Curie temperature and mechanical quality factor were decreased but grain size and electromechanical coupling factor(kp) was gradully increased. At 4 mol [%] PNW substitution. maximum kp of 0.567 was shown.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.11a
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• pp.280-283
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• 2002

In this study, the effects of $Nb_{2}O_{5}$ addition on microstructure and piezoelectric characteristics of PNW-PMN-PZT ceramics were investigated. As $Nb_{2}O_{5}$ addition amount is increased, grain size is gradully decreased. At 0.3wt%$Nb_{2}O_{5}$ addition composition ceramics, maximum density, tetragonality and piezoelectric characteristics were obtained.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.03a
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• pp.1-1
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• 2010

In this study, electrical properties of multilayer piezoelectric transformer sintered at $900^{\circ}C$ using pure Ag internel electrode was investigated. This multilayer piezoelectric transformer was fabricated as a ring-dot type. The multilayer piezoelectric transformer should have hight electromechanical coupling factor ($k_p$) and electromechanical qualiy factor ($Q_m$) in order to increase the efficiency of energy conversion between electrical and mechanical energy. The maximum values of $k_p$ and $Q_m$ showed 0.552 and 1320, respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.03a
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• pp.6-6
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• 2010

In this study, microstructural and piezoelectric characteristics of PNW-PMN-PZT ceramics manufactured using attrition milling method were investigated. Sintering temperature of the ceramics was varied from $980^{\circ}C$ to $1100^{\circ}C$. At the specimen sintered at $1100^{\circ}C$, mechanical quality factor(Qm) and dielectric constant showed the maxinum values of 2,373 and 1438, respectively. At the specimen sintered at $1080^{\circ}C$, electromechanical coupling factot(kp) also showed the maxinum value of 0.524.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.03a
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• pp.12-12
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• 2010

The piezoelecric properties of $(K_{0.5}Na_{0.5})(Nb_{0.96}Sb_{0.04})O_3$+$1.2mol%K_4CuNb_8O_{23}$+$xmol%La_2O_3$ lead-free piezoelecric ceramics were investigated as a function x. These ceramics were fabricated by conventional ceramics processing. Piezoelectric constant ($d_{33}$) and piezoelectric charge coefficient ($g_{33}$) of x=0.2 mol% composition exhibited good properties of 160.3pC/N and 37.4($10^{-3}Vm/N$), respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.645-648
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• 1999

With the variation of the sintering temperature and the amounts of B$_2$O$_3$, Bi$_3$O$_3$ and V$_2$O$_{5}$ , the densification and the piezoelectric properties of the MnO$_2$-doped PMN-PZT were investigated. The additives decreased the sintering temperature of ceramics. In the case of 0.5wt% B$_2$O$_3$, the sintering density, the mechanical quality factor, the electromechanical coupling factor and the piezoelectric constant were 7.51 (g/㎤), 1397, 51.1% and 305 (X10$^{-12}$ C/N) respectivly at 105$0^{\circ}C$. And the addition of lwt% Bi$_2$O$_3$, they were 7.59 (g/㎤) ,833,49.8% and 308 (X10$^{-12}$ C/N) respectivly at 1000 $^{\circ}C$.