• 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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• 2001.11a
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• pp.434-437
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• 2001

In this study piezoelectric and dielectric properties of Pb(Mn$\sub$1/3/Nb$\sub$2/3/)O$_3$-Pb(Zr,Ti)O$_3$ ceramics were investigated with Pb(Ni$\sub$1/3/Nb$\sub$2/3/)O$_3$ substitution. As the Pb(Ni$\sub$1/3/Nb$\sub$2/3/)O$_3$) substitution was increased, dielectric constant and electromechanical coupling factor (kp) were increased while mechanical quality factor decreased.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.33 no.6
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• pp.465-470
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• 2020

Heterolayered K(Ta,Nb)O₃/Pb(Zr,Ti)O₃ thin films on Pt/Ti/SiO₂/Si substrates were prepared by a sol-gel process and spin-coating method. The structural and electrical properties were measured to investigate the possibility of application as an electrocaloric effect device. All specimens exhibited dense and uniform cross-sectional structures without pores, and the average thickness of the specimen coated six times was approximately 394 nm. Curie temperatures were observed at 5℃ or less in type-I and 10℃ in type-II specimens, respectively. Type-II specimens coated 6 times showed a relative dielectric constant of 758 and remanent polarization of 9.71 μC/㎠ at room temperature. The maximum electrocaloric effect occurred between 20 and 25℃, slightly higher than their Curie temperature, and the electrocaloric property (ΔT) of the type-II specimens coated 6 times was approximately 1.2℃ at room temperature.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.12S
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• pp.1195-1199
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• 2003

In this study, in order to develop the low temperature sintering ceramics for multilayer piezoelectric transformer, dielectric and piezoelectric properties of PSN-PZT[0.91Pb(Sb$\sub$1/2/Nb$\sub$1/2/)$\sub$0.03/(Zr$\sub$0.495/Ti$\sub$0.505/)$\sub$0.97/O$_3$-0.04Pb(Ni$\sub$1/2/W$\sub$1/2/)O$_3$+0.05BiFeO$_3$+0.3wt％MnO$_2$+0.6wt％CuO〕 ceramics were investigated according to Zr/Ti ratio. As Zr/Ti ratio is increased, electromechanical coupling factor(k$\sub$p/) and dielectric constant increased and then decreased after the ratio of Zr/Ti=50/50. Also, mechanical qualify factor(Q$\sub$m/) decreased and then increased after the ratio of Zr/Ti=50/50.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.05c
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• pp.257-260
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• 2003

In this study, the structural, dielectric and piezielectric properities of $xPb(Mg_{1/3}Nb_{2/3})O_3-(0.5-x)Pb(Ni_{1/3}Nb_{2/3})O_3-0.5Pb(Zr_{0.3}Ti_{0.7})O_3$ ceramics were investigated with the substitution of $PbMg_{1/3}Nb_{2/3}O_3$. The results showed that the substitution of the $PbMg_{1/3}Nb_{2/3}O_3$ was effective in increasing the dielectric constant and electromechanical coupling factor $(K_p)$. The dielectric constant, dielectric loss and Kp showed the highest values of 4293, 2.4%, 0.59 relatively, when the substitution of amount of $PbMg_{1/3}Nb_{2/3}O_3$ was 5 mol%.

• Korean Journal of Materials Research
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• v.22 no.3
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• pp.150-154
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• 2012

Ti-6Al-4V ELI (Extra Low Interstitial) alloy have been widely used as alternative to bone due to its excellent biocompatibility, although it still has many problems such as high elastic modulus and toxicity. Therefore, biomaterials with low elastic modulus and non toxic characteristics have to be developed. A novel ${\beta}$ Ti-35wt%Nb-7wt%Zr-Calcium pyrophosphate (CPP) composite that is a biocompatible alloy without elemental Al or V was fabricated by spark plasma sintering (SPS) at $1000^{\circ}C$ under 70 MPa using high energy mechanical milled (HEMM) powder. The microstructure and phases of the milled powders and the sintered specimens were studied using SEM, TEM, and XRD. Ti-35wt%Nb-7wt%Zr alloy was transformed from ${\alpha}$ phase to ${\beta}$ phase in the 4h-milled powder by sintering. The sintered specimen using the 4h-milled powder showed that all the elements were distributed very homogeneously and had higher density and hardness. ${\beta}$ Ti alloy-CPP composite, which has nanometer particles, was fabricated by SPS using HEMMed powder. During the sintering process, $CaTiO_3$, TixOy, and CaO were formed because of the reaction between Ti and CPP. The Vickers hardness of the composites increases with the increase of the milling time and the addition of CPP. The biocompatibility of the Ti-Nb-Zr alloys was improved by addition of CPP.

• Journal of Sensor Science and Technology
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• v.9 no.3
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• pp.242-247
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• 2000

$Pb_{0.99}[(Zr_{0.6}Sn_{0.4})_{0.9}Ti_{0.1}]_{0.98}Nb_{0.02}O_3(PNZST)$ thin films were deposited by RF magnetron sputtering on $(La_{0.5}Sr_{0.5})CoO_3(LSCO)/Pt/Ti/SiO_2/Si$ substrate using a PNZST target with excess PbO of 10 mole%. The thin films deposited at substrate temperature of $500^{\circ}C$, and at RF power of 80W were crystallized to a perovskite phase after rapid thermal annealing(RTA). The thin films annealed at $650^{\circ}C$ for 10 seconds in air exhibited the good structures and electrical properties. The fabricated PNZST capacitor had a remanent polarization value of about $20\;{\mu}C/cm^2$ and coercive field of about 50 kV/cm. The reduction of the polarization after $2.2{\times}10^9$ switching cycles was less than 10%.

• Journal of Sensor Science and Technology
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• v.11 no.1
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• pp.48-53
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• 2002

Ferroelectric $Pb_{0.99}[(Zr_{0.6}Sn_{0.4})_{1-x}Ti_x]_{0.98}Nb_{0.02}O_3$(PNZST) thin films were deposited by a RF magnetron sputtering on $(La_{0.5}Sr_{0.5})CoO_3$(LSCO)/Pt/Ti/$SiO_2$/Si substrate using a PNZST target with excess PbO of 10 mole%. The crystallinity and electrical properties of the thin films with various composition ratio were investigated. The thin films deposited at the substrate temperature of $500^{\circ}C$ and the power of 80 W were crystallized to a perovskite phase after rapid thermal annealing(RTA) at $650^{\circ}C$ for 10 seconds in air. A PNZST thin films with Ti of 10 mole% showed the good crystallinity and ferroelectric properties. The remanent polarization and coercive field of the PNZST capacitor were about $20\;{\mu}C/cm^2$ and 50 kV/cm, respectively. The reduction of the polarization after $2.2{\times}10^9$ switching cycles was less than 10%.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.41 no.8
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• pp.858-868
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• 1992

0.085Ba(LaS11/2TNbS11/2T)OS13T-0.915Pb(ZrS1yTTiS11-yT)OS13T (0.45$\leq$y$\leq$0.65) transparent electrooptic ceramics were fabricated by two-stage sintering method. The structural, ferroelectric and electrooptic properties were investigated varying composition and second sintering time. Also the possibility of application to electrooptic device was studied. If we increase the PbZrOS13T contents, dielectric constants were increased and Curie temperature was decreased. In the composition of 0.55[mol] PbZrOS13T, electromechanical coupling factor and piezoelectric charge constant were the highest values of 43[%] and 173x10S0-12T[C/N], respectively. Mechanical quality factors were decreased with the increasing PbZrOS13T contents. Light transmittance was increased with wavelength when measured from 300[nm] to 900[nm], and with PbZrOS13T contents in the range of 0.50[mol]-0.65[mol], and had the highest value of 67[%] in the composition of 0.65[mol] PbZrOS13T. From the results of ferroelectric hysteresis loop and transmitted light intensity with electric field, the specimens with compositions of 0.65,0.60,0.55[mol] PbZrOS13T were applicable to electrooptic memory device and those with compositions of 0.50,0.45[mol] PbZrOS13T were applicable to linear electrooptic device.

• Proceedings of the KIEE Conference
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• 2000.11c
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• pp.494-496
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• 2000

The properties of piezoelectric and dielectric for 0.05Pb$(Mn_{0.4}W_{0.2}Nb_{0.4})O_3$ - $0.95PbZr_{x}Ti_{1-x}O_{3}$ compositions have been investigated. In the composition of 0.05Pb$(Mn_{0.4}W_{0.2}Nb_{0.4})O_3$-$0.95PbZr_{0.51}Ti_{0.49}O_{3}$, the values of $k_p$ and ${\varepsilon_{33}}^T/{\varepsilon}_0$ are maximized, but $Q_m$ was minimized ($k_p$=56.5[%], $Q_m$=1130, $d_{33}$=258[pC/N], ${\varepsilon_{33}}^T/{\varepsilon}_0$=1170). The grain size was suppressed and the uniformity of gram was improved at the $1100[^{\circ}C]$. Dielectric constant increase at the Ti rich, but decrease at the Zr rich after poling. Because the dielectric constant after poling is determined by compromising effects between dipole switching and electostriction inducing stress(dielectric constant increasing factor) and dipole rotation to the poling direction (dielectric constant decreasing factor).