• Title/Summary/Keyword: Relaxor ferroelectrics

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Piezoelectric Properties in PMN-based Relaxor Ferroelectrics (PMN계 완화형 강유전체에서의 압전물성)

  • Park, Jae-Hwan;Park, Jae-Gwan;Kim, Yun-Ho;Park, Soon-Ja
    • Korean Journal of Materials Research
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    • v.9 no.3
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    • pp.240-243
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    • 1999
  • Piezoelectric properties of O.9PMN-0.1PT relaxor ferroe1ectrics were investigated in the temperature range of $-40^{\circ}C~$100^{\circ}C$. After poled at $-40^{\circ}C$, electro-mechanical properties of the samples were measured by resonance antiresonance method. As the resonance behavior was shown in impedance spectrum obtained below $0^{\circ}C$, it can be c conduded that 0.9PMN-0.1PT is bona-fide ferroelectrics below the phase transition temperature. It is very noteworthy that electro-mechanical resonance occurs at the temperatures far above the phase transition temperature. It is coneluded that ferroelectricity in 0.9PMN-0.1PT relaxor were verified far above the phase transition temperature.

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Growth and physical properties of SrxBa1-xNb2O6 (x = 0.60, 0.75) single crystals

  • Kang, Bong-Hoon;Joo, Gi-Tae
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.20 no.2
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    • pp.65-68
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    • 2010
  • $Sr_{0.6}Ba_{0.4}Nb_2O_6$ (60SBN) and $Sr_{0.75}Ba_{0.35}Nb_2O_6$ (75SBN) single crystals were grown by Czochralski method. Growing direction was <001>, and as-grown crystals has well-developed (001) plane. Temperature- and frequency dependence of dielectric constant represent relaxor ferroelectrics. 60SBN has wider optical transmittance than 75SBN.

Piezoelectric Properties of PMN-PT Relaxor Ferroelectrics with $MnO_2$Addition ($MnO_2$첨가에 따른 PMN-PT계 완화형 강유전체에서의 압전특성)

  • 박재환;박주영;박재관;김병국;김윤호
    • Journal of the Korean Ceramic Society
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    • v.37 no.10
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    • pp.1021-1024
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    • 2000
  • PMN-PT계 완화형 강유전체에서 MnO$_2$첨가가 압전물성에 미치는 영향을 -40~10$0^{\circ}C$의 온도범위에 걸쳐 조사하였다. 각각의 시편들은 -4$0^{\circ}C$에서 1.0kV/mm의 전계를 10분간 가하여 분극처리를 한 후 승온하면서 공진 반공진법에 의해 압전물성을 측정하였다. 0.9MN-0.1PT계의 경우 MnO$_2$를 첨가하였을 때 $K_{p}$ 는 거의 유지되면서도 Q$_{m}$ 값이 큰 폭으로 상승하였는데, 0.5wt% MnO$_2$첨가의 경우 -4$0^{\circ}C$에서 95로부터 480으로 증가하였다. 일반 강유전체인 PZT계에 대한 MnO$_2$의 첨가효과와 비교할 때 PMN계 완화형 강유전체에서도 동일한 경향성을 보임을 확인하였다.

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Phase Transition Behaviors of Lead-Free Piezoelectric (Na1/2Bi1/2TiO3)(1-x)-(BaTiO3)x (납이 포함되지 않은 압전 특성의 (Na1/2Bi1/2TiO3)(1-x)-(BaTiO3)x 상전이 거동 연구)

  • Lee, Byoungwan;Luo, Haosu;Kim, Jung Kyu
    • Ceramist
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    • v.23 no.1
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    • pp.101-109
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    • 2020
  • In this study, the phase transition behaviors of lead-free (Na1/2Bi1/2TiO3)(1-x)-(BaTiO3)x (NBT-BT) are investigated by using Brillouin spectroscopy. The elastic properties, sound velocity and absorption coefficient of NBT-BT are characterized as a function of temperature along different crystallographic axes. The temperature dependences of the elastic constants of NBT-BT near the morphotropic phase boundary are determined for the first time. The unpoled NBT-BT single crystals exhibits the typical relaxor behaviors, presenting broad acoustic and dielectric anomalies. The application of electric field induced discontinuous changes in the elastic properties at ~110℃, which indicates field-induced phase transition occurred. The electric field also changes the dielectric constant from more relaxor-like to ferroelectric-like dielectric behavior.

Relaxation and Freezing in Pb-based Relaxer Ferroelectrics (Pb계 완화형 강유전체에서의 relaxation 및 freezing거동)

  • 박재환;김윤호;박재관
    • Korean Journal of Crystallography
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    • v.12 no.3
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    • pp.157-161
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    • 2001
  • The observe relaxation phenomena and freezing behavior in Pb(Mg/sub ⅓/Nb/sub ⅔/O₃, relaxor ferroelectrics, weak electric-field properties as well as strong electric-field properties were investigated. The temperature dependence of the dielectric properties obtained using the low electric-field of 1 V/w was investigated. 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-Filcher relation, a close agreement between the experimental data and equation was observed. The freezing temperature could be consistently calculated by the various methods.

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Effect of MnO$_2$ addition on the piezoelectric properties in 0.9Pb($Mg_{1/3}Nb_{2/3}$)$O_3$-0.1Pb$TiO_3$relaxor ferroelectrics (0.9Pb($Mg_{1/3}Nb_{2/3}$)$O_3$-0.1Pb$TiO_3$계 완화형 강유전체에서 MnO$_2$ 첨가에 따른 압전물성의 변화)

  • Park, Jae-Hwan;Park, Jae-Gwan;Kim, Byung-Kook;Kim, Yoon-Ho
    • Korean Journal of Materials Research
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    • v.11 no.6
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    • pp.498-501
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    • 2001
  • The effects of MnO$_2$ addition on the piezoelectric properties in 0.9Pb($Mg_{1/3}Nb_{2/3}$)$O_3$-0.1Pb$TiO_3$ relaxor ferroelectrics were studied in the ferroelectricity-dominated temperature range from -4$0^{\circ}C$ to 3$0^{\circ}C$. Dielectric, piezoelectric properties and electric-field- induced strain were examined to clarify the effect of MnO$_2$ addition. As the added amount of MnO$_2$ increase. dielectric and piezoelectric properties of Pb(Mg$_{1/3}$ Nb$_{2/3}$O$_3$ became harder. From the experimental results, it was suggested that Mn behaves as a ferroelectric domain pinning element.

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Correlations between the Polarization and Strain Induced by Electric field in $\textrm{0.9Pb}\textrm({Mg}_{1/3}\textrm{Nb}_{2/3})\textrm{O}_3$-$\textrm{0.1PbTiO}_3$ Relaxor Ferroelectrics ($\textrm{0.9Pb}\textrm({Mg}_{1/3}\textrm{Nb}_{2/3})\textrm{O}_3$-$\textrm{0.1PbTiO}_3$계 강유전체에서 전계인가에 따른 분극 및 변위의 상관관계)

  • Park, Jae-Hwan;Park, Jae-Gwan;Park, Sun-Ja
    • Korean Journal of Materials Research
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    • v.9 no.1
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    • pp.81-85
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    • 1999
  • Polarization and strain induced by unipolar electric field (P\ulcorner, S\ulcorner), those induced by bipolar electric field (P, S) and remanent polarization (P\ulcorner) were investigated in 0.9Pb(Mg\ulcornerNb\ulcorner)O$_3$-$0.1PbTiO_3$relaxor ferroelectric ceramics in the temperature range of $-50^{\circ}C$~$90^{\circ}C$. From the temperature dependence of polarization and strain, the transition from predominantly paraelectric (electrostrictive) to partially ferroelectric (piezoelectric) is visualized. Under the given temperature, the P\ulcorner/P\ulcorner is always larger than the S\ulcorner/S\ulcorner and the difference between them becomes larger ass the temperature decrease. The S\ulcorner/P\ulcorner increases as the temperature decreased below phase transition temperature. It was suggested that these experimental results might be explained with a simple rigid ion model concentrating on BO\ulcorner octahedron.

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Effect of PbTiO3 Concentration on the Properties of $Pb(Mg_{1/3}Nb_{2/3})O_3-PbTiO_3$ Relaxor Ferroelectrics -II. Phase Transition and Electric-field-induced Strains- ($Pb(Mg_{1/3}Nb_{2/3})O_3-PbTiO_3$계 완화형 강유전체의 특성에 미치는 PbTiO3 첨가량의 영향 -II. 상전이 및 전계인가 변위특성-)

  • 박재환;김인태;김동영;조서용;흥국선;박순자
    • Journal of the Korean Ceramic Society
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    • v.33 no.5
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    • pp.556-562
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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 the electric-field-induced strains and the pyroelectric coefficients of (1-x)PMN-xPT (x=0.1-0.4) were investigated in the temperature range -50~20$0^{\circ}C$. For x=0.1~0.35 where the phase transi-tion is diffusive the strain has a maxima at the temperature of maximum pyroelectric coefficient (depolrizing temperature) rather than the temperature of maximum dielectric constant. For x=0.4 where the phase transition is relatively sharp the strain decreases monotonically as the temperature increases. Relationships among the above experimental results are discussed.

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Field Induced Phase Transition in $0.6Pb(Ni_{1/3}Nb_{2/3})O_3-0.31PbTiO_3-0.09PbZrO_3$ Relaxor Ferroelectrics ($0.6Pb(Ni_{1/3}Nb_{2/3})O_3-0.31PbTiO_3-0.09PbZrO_3$ 완화형 강유전체의 전계 유기 상전이 현상)

  • 윤만순;장현명;정회승;최병철
    • Journal of the Korean Ceramic Society
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    • v.34 no.6
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    • pp.620-628
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    • 1997
  • The possibility of the existence of a field-induced micro-macrodomain switching was proposed and examined using 9 mol % PbZrO3-doped 0.6Pb(Ni1/3Nb2/3)O3-PbTiO3 (PNN-PT) systems having rhombohedral symmetry at room temperature. the thermally depoled (freshly prepard) specimens prepared from the rhombohedral side of the system exhibited a relaxor behavior for the whole range of temperature examined (for T

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