• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.3
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• pp.220-226
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• 2000

The piezoelectric material for piezoelectric transformer needs the high electromechanical coupling factor( $k_{p}$) the piezoelectric constant( $d_{33}$) and the mechanical quality factor( $Q_{m}$)in order to obtain high voltage step-up ratio and low temperature rising. In this study the piezoelectric transformers were fabricated using Pb［$Zr_{0.45}$/ $Ti_{0}$48//L $u_{0.02}$(M $n_{1}$3//S $b_{2}$3/)$_{0.05}$］ $O_3$(PMS-PZT) and Pb［Z $r_{0.25}$/ $Ti_{0.375}$(M $g_{1}$3//N $b_{2}$3/)$_{0.375}$］ $O_3$+0.5wt%Mn $O_2$(PMN-PZT) ceramics. The piezoelectric properties of PMS-PZT and PMN-PZT were measured. The voltage set-up ratios of the piezoelectric transformers using PMS-PZT and PMN-PZT were the value of 15, 20 respectively under 100$_{KΩ}$ in Rosen type transformer.r.ormer.r.r.r.r.r.r.

• Proceedings of the Korean Ceranic Society Conference
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• 2000.04a
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• pp.137.1-137.1
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• 2000

• Proceedings of the KIEE Conference
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• 1992.07b
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• pp.753-756
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• 1992

The piezoelectric ceramics of PMS-PZT was made in the radial mode disk. As the results, in the application of filter required conditions: that is, higher-values for piezoelectric properties($K_p$, $Q_m$) and lower-values for stabilities of $F_{\tau}$(temp. coefficient, aging rate), 5PMS-51PT-44PZ composition statified well. This composition was made in the dot-ring type. Asthe results, with increasing $n^2$ both $Q_m$ and S had high values, decreasing $n^2$ both $K_p$ and BW had low values when the diameter of sintered bodies were constant. Therefore, curve of filter characteristic have sharped with increasing $n^2$ and BW broadened with decreasing $n^2$.

• Korean Journal of Materials Research
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• v.14 no.11
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• pp.764-768
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• 2004

Perovskite Pb(Mn_{1/3}Sbu_{2/3})O_2-Pb(Zr,Ti)O_3\;(PMS-PZT) was prepared and ZnO doping effects on its piezoelectric properties were investigated. Pyrochlore phase was not identified in the PMS-PZT ceramics with $0\sim5\;mol\%$ ZnO sintered at $1100^{\circ}C$ for 2 hrs, and maximum sintered density of $7.92 g/cm^3$ was obtained. Piezoelectric charge constant and voltage constant increased to $359{\times}10^{-12}\;C/N\;and\;22.5{\times}10^{-13}\;Vm/N$, respectively, with increasing ZnO content. Mechanical quality factor reduced considerably with increasing ZnO content. When the ZnO content was 3 $mol\%$, electromechanical coupling factor and relative dielectric constant showed maximum values of $56\%$ and 1727, respectively. This should be evaluated by complicated variations of sintered density, tetragonality of lattice, grain size, and A-site vacancy generated by ZnO addition and $Zn^{2+}$ substitution.

• Proceedings of the Korean Ceranic Society Conference
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• 2002.10a
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• pp.95.2-95
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• 2002

• Journal of the Korean Ceramic Society
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• v.37 no.4
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• pp.295-301
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• 2000

The effect of V2O5 addition on the low temperature sintering of Pb(Mn1/3Sb2/3)O3-PZT ceramics, which is known as a prominent material for piezoelectric transformer application was studied, and the densification behavior and piezoelectric characteristics of the samples as a function of heating rate were also examined. V2O5 led the system to liquid phase sintering by forming liquid phase during sintering, which accelerated densification through the particle rearrangement in the early stage of sintering. The liquid phase mostly existed at grain boundaries retarded the evaporation of PbO, while the densification temperature and the weight loss of V2O5-free samples were higher than those of samples with V2O5. Faster heating improved the densification of the samples regardless of V2O5 addition. The low temperature sintering at 100$0^{\circ}C$ was achieved in PMS-PZT ceramics with high density and reasonable dielectric and piezoelectric characteristics. This result revealed optimistic way to the development of multi-layered piezoelectric transformers.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1992.05a
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• pp.73-76
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• 1992

In this study, piezoelectric ceramics of composition 0.08Pb(Mn$\sub$1/3/Sb$\sub$2/3/)O$_3$ were manufactured by the Hot-press method and structural, piezoelectrical properties and temperature stability were investigated with addition of 0, 02, 0.4, 0.6, 0.8, 1.0 [wt%] Cr$_2$O$_3$. Also the SAW delayline was fabricated and the propagation characteristics of SAW were considered with SAW theories.

• Journal of the Korean Ceramic Society
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• v.37 no.4
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• pp.395-401
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• 2000

In this study, we chose the basic composition which indicated the best electrical properties by change of x content(0, 0.05, 0.1, 0.15, 0.2, 0.25 mol respectively) in xPb(Mn1/3Sb2/3)O3-(1-x)Pb(Zr0.52Ti0.48)O3 ceramics. And we substituted Cd2+ for Pb2+ site, then observed the sintering behavior, microstructure and electrical propertties according to the various sintering temperature. The basic composition was the 0.05PMS-0.95PZt, and it showed single perovskite phase and excellent properties. In case of Cd2+ substitution, we were able to sinter at 90$0^{\circ}C$ which was lower than conventional sintering temperature(1200~130$0^{\circ}C$). Especially, when the 2mol% substituted PMS-PZT specimens were sintered at 90$0^{\circ}C$ for 2h, we obtained the p=7.6g/㎤, kp=56%, Qm=520 and made sure of a position of Cd2+ substitution by observing lattice parameter, phase transition temperature. From this results, we could infer that because Cd2+ substituted fro A-site, low temperature sintering of Cd2+ substituted PMS-PZT without any loss of electrical properties shows its applicability for the piezoelectric ceramic transformer.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.11a
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• pp.250-253
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• 1997

Generally, Piezoelectric ceramics based lead-zirconate-titanate(PZT) system are well known to use in high power devices. In this pacer. Pb(Mn$\sub$1/3//Sb$\sub$2/3/)O$_3$(PMS) ceramics which have been shown to be adaptable for a high power usage is introduced. The stability of piezoelectric properties in PZ-PT-PMS solid solution system such as piezoelectric constants. electromechanical coupling coefficient and mechanical quality factor is discussed by the addition effect of CeO$_2$ as a additive. The CeO$_2$ ratio ranges from 0 to 2 wt%. The resonant and anti-resonant frequencies. mechanical quality factor, and force factor are also measured as a function of vibration velocity

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07b
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• pp.830-833
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• 2004

Voltage step-down characteristics of Ring/Dot type piezoelectric transformer were examined with increasing input voltage from $10\;V_{pp}$ to $140V_{pp}$. Then the output load resistance was fixed to $125\;\Omega$. The voltage gain showed constant value till the input voltage of $70\;V_{pp}$. And then it linearly decreased till the input voltage of $140V_{pp}$. The output voltage of fabricated piezoelectric transformer increased with increasing input voltage. And driving frequencies when the output voltage was maximum value were changed according to input voltage. Frequency shifts and temperature rise of fabricated sample showed 2 kHz, $13^{\circ}C$, respectively when input voltage was changed from $10\;V_{pp}$ to $140V_{pp}$. Because of the temperature rise of fabricated piezoelectric transformer, the step-down characteristics of it was deteriorated above the input voltage of $70\;V_{pp}$.