• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.34 no.6
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• pp.466-474
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• 2021

[011] poled ternary Pb(In_1/2Nb_1/2)O₃-Pb(Mg_1/3Nb_2/3)O₃-PbTiO₃ (PIN-PMN-PT) single crystals have been investigated for active materials for acoustic transducers because of their high piezoelectric properties in both shear and transverse modes. In order to use [011] poled PIN-PMN-PT single crystals for acoustic transducers, the characterization of full-matrix material properties is required. In this study, full sets of compliance, dielectric, and piezoelectric constants of [011] poled rhombohedral PIN-PMN-PT were measured by a resonance method. Dimensions and geometries of 12 samples were proposed for measuring 17 independent material constants of [011] poled rhombohedral PIN-PMN-PT single crystals. Two sets of samples with different PT concentrations, 0.24PIN-0.49PMN-0.27PT and 0.24PIN-0.46PMN-0.30PT, were fabricated and their material properties were measured. Measured impedance spectra and simulated impedance spectra of the samples were compared to check the accuracy of the measurements.

• Journal of the Korean Ceramic Society
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• v.32 no.8
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• pp.938-944
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• 1995

Dielectric properties and the stabilization of perovskite phase for the (1-y)Pb(Mg(1-x)/3Znx/3Znx/3Nb2/3)O3-yBaTiO3 ((1-y)PM1-xZxN-yBT) ceramics have been investigated as a function of amount of x and y. In the (1-y)PM0.6Z0.4N-yBT ceramics, the amount of pyrochlore phae was decreased by the addition of 2 mol% BT and the dielectric constant was increased. However, the dielectric constant decreased with further addition of BT even though pyrochlore phase was decreased. Dielectric prooperties in (1-y)PM0.6Z0.4N-yBT ceracmis were affected by the character of the BT rather than the amount of pyrochlore phase. The phase transitions were broadened and phase transition temperatures were lowered by the increase of BT contents.

• Electrical & Electronic Materials
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• v.1 no.2
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• pp.152-161
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• 1988

Pb(Zr, Ti)O$^{3}$-Pb(Mg, Nb)O$^{3}$계에 MnO$_{2}$첨가량을 변화시켜 소결성, 미세구조, 유전상수, 비저항 및 압전특성에 미치는 영향을 XRD, EDAX 및 SEM을 이용하여 미세구조를 관찰하고 실험을 통하여 전기적 성질에 미치는 영향을 밝혔다. 비저항의 변화없이 그레인 성장이 억제되는 $MnO_{2}$의 첨가량은 0.4wt%이었으며 이때 분말의 합성이 촉진되어 소성된 시편의 밀도가 증가하였다. 그러나 고상반응의 범위를 벗어나는 과잉 $MnO_{2}$는 편석이 되어 그레인 경계상에 모임이 확인되었고 또한 기공을 형성하여 밀도를 낮추었다. $Mn^{+4}$는 $Mg^{+2}$ 와 치환되어 페로브스카이트 구조의 "A" 결핍을 유발하였으며 이것이 비저강을 감소시키는 원인으로 밝혀졌다.감소시키는 원인으로 밝혀졌다.

• Proceedings of the Korean Ceranic Society Conference
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• 2003.10a
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• pp.195.1-195
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• 2003

• Journal of the Korean Ceramic Society
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• v.33 no.4
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• pp.391-398
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• 1996

In order to understand the electrostrictive behavior of Pb(Mg1/3Nb2/3)O3-PbTiO3(PMN-PT) solid solutions the dielectric constants and the electric-field-induced strains in (1-x)PMN-xPT (x=0.0-0.4) were investigated in the temperature range -5$0^{\circ}C$-20$0^{\circ}C$. Powder of (1-x)Pb(Mg2/3Nb2/3)O3-xPbTiO3 (x=0.0, 0.1, 0.2, 0.3, 0.35, and 0.4) were prepared from the oxide forms of Pb, Mg, Nb and Ti via a columbite precursor method As the amount of PbTiO3 increases the temperature of maximum dielectric constant(T$\varepsilon$max) increases and the phase transition become less diffusive. The strain maximum occurs only when the diffuse phase transition occurs from rhombohedral to cubic or rhombohedral to tetragonal as in x=0.1-0.35 The strains monotonically decrease with temperature in the materials in which phase transition occurs from tetragonal to cubic as in x=0.4.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.7
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• pp.562-566
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• 2001

The effects of MnO$_2$ addition on the properties in Pb(Mg$_{1}$3/Nb$_{2}$3/)O$_3$ relaxor ferroelectrics were studied in the phase transition temperature range from -4$0^{\circ}C$ to 11$0^{\circ}C$. Specimens were made via solid state processing method. Dielectric properties, piezoelctric properties, electric-field-induced strain were examined to clarify the effect of MnO$_2$ addition in 0.9MN-0.1PT. As the amount of MnO$_2$ increases, the maximum dielectric constant and the dielectric loss decreases. Q$_{m}$ increased by increasing the doping contents of Mn. When 0.5wt% MnO$_2$ was doped, Q$_{m}$ increased from 95 to 480. The electric-filed-induced strain and polarization decreases as the amount of MnO$_2$ increases. From the experimental results, it was suggested that Mn behaves as an ferroelectric domain pinning element.ent.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.45 no.2
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• pp.235-241
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• 1996

In this paper dielectric and electrostrictive strain properties of (1-y-x)Pb(Mg$_{1/3}$Nb$_{2/3}$)O$_{3}$-PbTiO$_{3}$$-yPbTiO_{3}-xSrTiO_{3}[(1-y-x)PMN-yPT-xST]$ ceramics fabricated by using columbite precursor method have been investigated with the substitution of SrTiO$_{3}$(ST). Dielectric constant of the specimens increased with the increase of ST content up to 5[m/o] and decreased with further substitution of ST. And the pyrochlore phase decreased with the increase of ST content up to 5[m/o] in XRD analysis. The elimination of the pyrochlore phase improved dielectric constants. The electrostrictive strains generated by AC electric field have the highest value at 5[m/o] SrTiO$_{3}$ addition and the hysteresis of strain ranged from 12 to 20[%]. The electrostrictive strain at various temperature investigated in the temperature range of $-50[^{\circ}C]~74[^{\circ}C].$ In higher temperature than phase transition region, it showed paraelectric property which shows very small hystersis.

• Journal of the Korean Ceramic Society
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• v.30 no.7
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• pp.543-548
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• 1993

Stability and formation of Pb(Mg1/3Nb2/3)O3 (PMN) phase synthesized in Li2SO4-Na2SO4 molten salts have been investigated. And powder characteristics of PMN have been studied with a variation of processing parameters such as temperature, time, amount of the salts, and excess PbO. More ratio of Li2SO4 to Na2SO4 influences the percentage of perovskite phase due to the difference of the eutectic point of the salts, but does not influence the powder characteristics. The shape of PMN particles shows faceted morphology with bimodal distribution consisting with large and submicron parts. Particle size of PMN increased greatly with increasing soaking time or amount of salts rather than temperature. The addition of excess PbO resulted in round PMN crystallites without submicron particles. These results are discussed by XRD, SEM and thermal analyses.

• Journal of the Korean Ceramic Society
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• v.38 no.10
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• pp.953-957
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• 2001

To study various relaxation phenomena of $Pb(Mg_{1/3}Nb_{2/3})O_3$ relaxor ferroelectrics, weak electric-field properties as well as strong electric-field properties were investigated in the frequency range from 1 Hz to 100 kHz. The temperature dependence of the dielectric properties were measured under the low electric-field of 1 V/mm in the phase transition temperature range from $-40^{\circ}C$ to $90^{\circ}C$. The dielectric properties obtained from the slope of the dielectric hysteresis loop and the temperature dependence of the pyroelectric properties were also investigated. When fitting all the experimental data with the Vogel-Fulcher relation, experimental data were agreed with the equation closely. Thus, dielectric relaxations could be modeled by the Vogel-Fulcher relation not only for the low electric-field but also for the high electric-field.

• Journal of the Korean Ceramic Society
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• v.37 no.5
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• pp.491-496
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• 2000

Single phae Pb(Mg1/3Nb2/3)O3-based solid solutions, the Mg2+ of which are replaced by 20mol% of Ni2+, Zn2+, Cd2+, and the Pb2+ of which are replaced by 0∼20 mol% of La3+, were synthesized and their ordering structures of B-site cations were investigated by XRD and TEM. The B'-site cations (Mg2+, Ni2+, Zn2+, Cd2+) are disordered while these B'-site cations and the B"-site cations (Nb5+) are nonstoichiometrically 1:1 ordered within the ordered nano-domains dispersed in the Nb5+-rich disordered matrix. The charge imbalance between the B'-rich ordered nano-domains and the B"-rich disordered matrix are compensated by the doping of electron donor such as La3+, which enhances the degree of nonstoichiometric 1:1 ordering. For a given La3+ content, the degree of nonstoichiometric 1:1 ordering increases as the average ionic size difference between the B'-and B"-site cations increases, Ni2+