• Proceedings of the Korean Ceranic Society Conference
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• 2003.10a
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• pp.98.2-98
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• 2003

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.335-336
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• 2006

• Journal of the Korean Ceramic Society
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• v.37 no.1
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• pp.102-109
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• 2000

When PbZrO3 (PZ) and PbTiO3 (PT) particles were scattered on polished surfaces of sintered Pb(Zr0.52Ti0.48)O3 (PZT; Zr/Ti=1.08) and then annealed, the PZT grain boundaries migrated. Near the scattered particles, grain boundaries were corrugated and thus the grain shape changed from a normal one to irregular ones. Especially, near the scattered PZ particles, fast grain growth occurred. In the regions swept by moving grain boundaries, the Zr/Tiratio was measured to be about 1.35 for of PZ scattering and about 0.8 for PT scattering, respectively. This result indicates that the grain boundary migration was induced by alloying of Zr and Ti ions in PZT grains, as in usual diffusion induced grain boundary migration(DIGM). A calculation showed that higher coherency strain energy was induced for PT scattering because of higher alloying of Ti than of Zr.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.331-332
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• 2006

Ag-ceramic composite materials were investigated as internal electrodes for multilayer ceramic actuators (MLCA). Ag-ceramic pastes were prepared by adding PZT-based ceramic powders to a Ag patse in a range of 0 to 50 wt.%. PZT/Ag-PZT multilayered laminates were fabricated by tape casting and fired at low temperatures below $950^{\circ}C$. The addition of ceramic into the Ag electrode resulted in a decrease in the thermal expansion mismatch between the electrode and the ceramic sheet. The maximum strain of PZT/Ag-PZT multilayered actuators were $9{\times}10^{-4}$ under an electric field of 2.5MV/m. In conclusion, Ag-PZT composite materials are efficient for low cost piezoelectric MLCAs.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.5 no.2
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• pp.135-141
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• 1995

Abstract The sintering behavior and the electrical properties of sintered PZT ceramics using 2.45 GHz microwave energy were investigated. The ceramics were sintered between $1050 ~ 1130^{\circ}C$ for 5 min. Sintered body with high density and good electrical properties were achieved as the sintering temperature increases. Above $1090^{\circ}C$, however, the bulk density was decreased due to the volatilization of PbO component, and also electrical properties were decreased. The relative dielectric constant, mechanical Quality factor, electro- mechanical coupling factor of microwave sintered body at $1090^{\circ}C$ without PbO atmosphere were 1900, 80, 0.53 respectively, which were comparable to conventional sintering values. The sintering process completed within 20 min using microwave hybrid energy. The processing time and the amount of energy con-sumption could be reduced by microwave hybrid energy assisted rapid sintering.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1244-1245
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• 2008

Recently, piezoelectric transformer is applied to wide fields. Multi layer piezoelectric transformer has the advantage of high step up ratio, electromechanical coupling coefficient(Kp) and mechanical quality factor(Qm), but is indicated of peeling-phenomenon of electrode, rising sintering temperature made price of costly electrode. So in this study, it discuss on method for fabrication of rosen type piezoelectric transformers. For the fabrication as rosen type piezoelectric transformers, synthesized the powder using 0.01Pb$(ni_{1/3}Nb_{2/3})O_3$ - 0.08Pb$(Mn_{1/3}Nb_{2/3})O_3$ - 0.91Pb$(Zr_{0506}Ti_{0496})O_3$ (abbreviated as PNN-PMN-PZT) ceramics. The density, microstructure, dielectric and piezoelectric properties as a function of sintering temperature were investigated. The results indicated that the optimized properties of ceramics were obtained at sintering temperature of 1200$^{\circ}C$, showed the value of $d_{33}$=273pC/N, $K_p$=0.60 $Q_m$=1585, ${\varepsilon}_r$=1454, density=7.917$g/cm^3$ and $tan{\delta}$=0.0064.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.11
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• pp.1174-1177
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• 2004

The dielectric and piezoelectric properties of silver added 0.96 Pb(Z $r_{0.52}$ $Ti_{0.48}$) $O_3$-0.04 Pb(Mn,W,Sb,Nb)$_3$ ceramics were examined. By varying the contents of silver(0.0, 0.4, 1.0 mol%), the effect of silver addition on PZT-PMWSN ceramics was investigated at various sintering temperature(900, 1000, 1100 $^{\circ}C$). As increasing silver contents, the relative dielectric constant was increased and sinterability was enhanced. At the specimen with 0.4 mol% Ag and sintered at 1000 $^{\circ}C$, electromechanical coupling factor( $k_{p}$), mechanical quality factor( $Q_{m}$), dielectric constant($\varepsilon$$_{r}$) and dielectric loss were 0.502, 811, 991, 0.006, respectively. The results showed that the PZT-PMWSN/Ag composites have enhanced piezoelectic and dielectric properties and sintering temperature was lowered.red.

• Journal of the Korean Ceramic Society
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• v.48 no.5
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• pp.467-470
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• 2011

Pb(Zr,Ti)$O_3$ (PZT) based ceramics with superior piezoelectric properties have been extensively used in various domestic and industrial appliances. However, PZT ceramics causing environmental contamination and health problems need to be eventually replaced by any of Pb-free materials. $(Na_{0.53}K_{0.47})(Nb_{1-x}Ta_x)O_3$ (NKNT), one of Pb-free piezoelectric ceramics, has long been known but its properties are not fully understood and developed. In this study, dielectric and piezoelectric properties of Pb-free NKNT ceramics were studied with Ta substitution for B-site at x = 0~0.6. It was found that polymorphic phase transition (PPT) between orthorhombic and tetragonal phases was notably influenced by Ta substitution. The highest piezoelectric coefficient ($d_{33}$) of 284 pC/N was occurred at x = 0.45.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.11
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• pp.688-692
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• 2017

$Pb(Zr,\;Ti)O_3$ (PZT) is a piezoelectric material applied in a typical actuator and has been actively studied. However, in order to overcome the limitations of PZT, piezoelectric ceramics comprising mixed solid solutions of PZT with various relaxer electric materials have been studied. The $Pb(Zn_{1/3}Nb_{2/3})-Pb(Ni_{1/3}Nb_{2/3})-Pb(Zr,\;Ti)O_3$ (PZN-PNN-PZT) piezoelectric ceramic, known to have high piezoelectric constant and electromechanical coupling coefficient, was studied herein. The piezoelectric characteristics with various Zr contents (Zr/Ti ratios), PZN molar ratios, and sintering temperatures were compared. The piezoelectric properties of $d_{33}=580pC/N$ and $k_P=0.68$ were obtained with the $0.1PZN-0.2PNN-0.7PbZr_{0.46}Ti_{0.54}O_3$ composition sintered at $1,290^{\circ}C$.

• Journal of the Korean Ceramic Society
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• v.45 no.11
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• pp.681-687
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• 2008

The sintering and electrical properties of the hydrothermal PSZT powders obtained by substituting 4, 6 and 8mol% Sr for Pb in PZT lattice structure were investigated. The lattice constant and particle size decreased in proportion to a quantity of Sr. The sintering properties of PSZT powders showed $7.754g/cm^3$ of sintered density and $4{\mu}m$ of grain size at sintering temperature of $1250^{\circ}C$. Curie temperature lowered gradually from $363.6^{\circ}C\;to\;319.2^{\circ}C$ and relative dielectric constants increased rapidly by a quantity of Sr. In comparison to PZT, moreover, the quality factor of PSZT was increased more than three times with increase of Sr mole ratio, and piezoelectric constant $(d_{31}\;and\;g_{31})$ was decreased. It was found that dielectric loss of PSZT was decreased by 0.574% which was half of PZT.