• 한국세라믹학회지
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• 제50권6호
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• pp.545-550
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• 2013

Piezoelectric PMN-29PT single crystal multilayer actuators [100 $mm^2$ in cross section and 22 mm in length] are designed and fabricated by stacking square plates [$10{\times}10{\times}0.5(t)\;mm^3$] of PMN-29PT single crystals having a $d_{33}$ of about 1,500 pC/N. The characteristics of PMN-29PT multilayer actuators are compared with those of P-025.40P multilayer PZT ceramic actuators [490 $mm^2$ in cross section and 60 mm in length] produced by PI in Germany. Even though the total volume of the PMN-29PT single crystal multilayer actuator is only about 7.5% of that of the P-025.40P ceramic multilayer actuator, PMN-29PT single crystal multilayer actuators are expected to show very similar properties to P-025.40P ceramic actuators in terms of static stroke and blocking force. Therefore, on the basis of their smaller mass and volume compared to the conventional PZT ceramic multilayer actuators, piezoelectric PMN-29PT single crystal multilayer actuators have significant potential regarding the development of various high performance actuators for aerospace subsystems.

• 한국전기전자재료학회논문지
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• 제28권12호
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• pp.787-791
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• 2015

In this paper, the growing orientation of PMN-PT single crystal is analyzed using the Laue-Back Reflection Method. Two kinds of PMN-PT single crystals are grown using the Bridgman growing method in the [001] and [111] directions and their the Laue photographs are simulated assuming cubic crystal systems. From the comparison between simulation and test results, it can be concluded that the single crystals are grown in the desired crystal orientations.

• 비파괴검사학회지
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• 제27권4호
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• pp.313-320
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• 2007

일반적으로 비파괴 검사용 초음파 탐촉자는 PZT를 이용한 압전소자가 많이 이용되어 왔다. 최근 압전특성이 PZT보다 크게 뛰어난 PMN-PT 압전 단결정 재료가 개발되어 초음파를 이용한 비파괴 평가 분야에 폭넓게 활용될 것으로 기대되고 있다. 본 연구는 PMN-PT를 이용하여 발전설비 고감쇠 재료의 비파괴 평가에 적합한 초음파 탐촉자를 개발하기 위하여 수행되었다. KLM 모델을 이용하여 초음파 탐촉자의 특성을 시뮬레이션 하였으며 이를 기반으로 하여 중심주파수 1 및 2.25 MHz PMN-PT 종파용 초음파 탐촉자를 제작하여 상용 초음파 탐촉자와 그 성능을 비교하였다.

• 한국전기전자재료학회논문지
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• 제17권1호
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• pp.31-38
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• 2004

PMN-PT, a piezoelectric single crystal, has many useful applications such as sensors and actuators. In this paper, all the elastic, piezoelectric, and dielectric constants of the PMN-32％PT single crystals were measured by the resonance method. For the rhombohedral symmetry, a total of twelve independent material constants were measured such as six elastic compliance constants at constant electric field, two dielectric constants at constant stress, and four piezoelectric constants d. Seven sets of crystal samples of each different geometry were prepared for the measurement of length-thickness extensional, thickness extensional, radial, length extensional and thickness shear modes of vibration, respectively. In order to check the validity of the measurement, experimental impedance spectrum of the PMN-PT crystal was compared with numerical data spectrum calculated with the measured material constants. The good agreement between the two spectra confirmed validity of the results in this paper.

• 한국세라믹학회지
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• 제55권3호
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• pp.290-298
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• 2018

In order to investigate the effect of thickness on the dielectric and piezoelectric properties of (001) PMN-29PT single crystals, three different types of PMN-29PT samples were prepared using the solid-state single crystal growth (SSCG) method: high density crystal [99%], low density crystal [95%], and high density crystal doped with Mn [98.5%]. When their thickness decreased from 0.5 mm to 0.05 mm, their dielectric constant ($K_3{^T}$), piezoelectric constants ($d_{33}$ and $g_{33}$), and electromechanical coupling factor ($k_t$) decreased continuously. However, their dielectric loss (tan ${\delta}$) increased. The addition of Mn to PMN-PT induced an internal bias electric field ($E_I$), increased the coercive electric field ($E_C$), and prevented local depoling. Therefore, Mn-doped PMN-PT crystals show high stability as well as high performance, even in the form of very thin plates (< 0.2 mm), and thus are suitable for application to high frequency composites, medical ultrasound probes, non-destructive testing devices (NDT), and flexible devices.

• 한국음향학회지
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• 제24권3호
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• pp.127-132
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• 2005

이식형 인공중이용 트랜스듀서는 주파수 특성 및 구동 성능이 우수해야 하고 크기가 작아야 한다. 이러한 트랜스듀서로서 단결정 압전 재료인 PMN-PT를 이용한 적층형 액츄에이터를 제안하였고, 유한요소해석 및 제작실험을 통해 그 타당성을 밝혔다. 실험에서는 두께 $0.2{\cal}mm$를 갖는 시편을 14층으로 쌓아 최종적으로 $1{\cal}mm{\times}1{\cal}mm{\times}2.8{\cal}mm$ 크기의 PMN-PT 적층형 액츄에이터를 제작하였다. 제작된 PMN-PT 액츄에이터의 성능은 Impedance Spectrum과 구동변위 측정을 통해 PZT 액츄에이터와 비교, 평가하였고, 이를 통해 단결정 재료인 PMN-PT를 이용할 경우 우수한 성능의 인공중이용 액츄에이터 제작이 가능함을 확인하였다.

• 한국전기전자재료학회논문지
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• 제37권4호
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• pp.412-419
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• 2024

Mn-doped Pb(In_1/2Nb_1/2)O₃-Pb(Mg_2/3Nb_1/3)O₃-PbTiO₃ (Mn:PIN-PMN-PT) single crystals, which exhibit improved phase transition temperatures and coercive field properties compared to Pb(In_1/2Nb_1/2)O₃-Pb(Mg_2/3Nb_1/3)O₃-PbTiO₃ (PIN-PMN-PT) single crystals, are expected to be utilized in high-power acoustic transducers. Bridgeman method, growing single crystals along the axial direction from melt, is most widely used method for single crystal growth with large size and high quality. However, single crystal boules grown by the Bridgeman method demonstrate a PT compositional variation, giving rise a distribution of crystal structure and material properties along the growing axis. To employ piezoelectric single crystals grown by the Bridgeman method for acoustic transducers, it is essential to investigate their overall property distribution. In this study, the compositional distribution and property variation of Mn:PIN-PMN-PT single crystals grown by the Bridgeman method was investigated. Measured compositional distribution of PT was from 29% to 32.5% in the Rhombohedral crystal region of the boule. Two types of specimen, [011]-poled Mn:PIN-PMN-29PT and Mn:PIN-PMN-32PT single crystals, were fabricated and tested to obtain full property variation at both ends of the Rhombohedral crystal region. The properties related to the 32 directional vibration mode and the properties related to high-power driving were measured to confirm the overall distribution of properties by composition.

• 한국세라믹학회지
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• 제54권2호
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• pp.150-157
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• 2017

Three types of piezoelectric single crystals [PMN-PT (Generation I $[Pb(Mg_{1/3}Nb_{2/3})O_3-PbTiO_3]$), PMN-PZT (Generation II $[Pb(Mg_{1/3}Nb_{2/3})O_3-Pb(Zr,Ti)O_3]$), PMN-PZT-Mn (Generation III)] were grown by the solid-state single crystal growth (SSCG) method, and their dielectric and piezoelectric properties were measured and compared. Compared to (001) PMN-PT and PMN-PZT single crystals, the (001) PMN-PZT-Mn single crystals exhibited a higher transition temperature between the rhombohedral and tetragonal phases ($T_{RT}=144^{\circ}C$), as well as a higher coercive electric field ($E_C=6.3kV/cm$) and internal bias field ($E_I=1.6kV/cm$). The (011) PMN-PZT-Mn single crystals showed the highest coercive electric field ($E_C=7.0kV/cm$), and the highest stability of $E_C$ and $E_I$ during 60 cycles of polarization measurement. These results demonstrate that both Mn doping (for higher electromechanical quality factor ($Q_m$)) and a (011) crystallographic orientation (for higher coercive electric field and stability) are necessary for high power transducer applications of these piezoelectric single crystals. Specifically, the (011) PMN-PZT-Mn single crystal (Gen. III) had the highest potential for application in the fields of SONAR transducers, high intensity focused ultrasound (HIFU), ultrasonic motors, and others.

• 한국세라믹학회지
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• 제55권2호
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• pp.166-173
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• 2018

In order to investigate the effect of Mn on the dielectric and piezoelectric properties of PMN-PT [$Pb(Mg_{1/3}Nb_{2/3})O_3-PbTiO_3$], four different types of 71PMN-29PT samples were prepared using the solid-state single crystal growth (SSCG) method: (1) Undoped single crystals, (2) undoped polycrystalline ceramics, (3) Mn-doped single crystals, and (4) Mn-doped polycrystalline ceramics. In the case of single crystals, the addition of 0.5 mol% Mn to PMN-PT decreased the dielectric constant ($K_3{^T}$), piezoelectric charge constant ($d_{33}$), and dielectric loss (tan ${\delta}$) by about 50%, but increased the coercive electric field ($E_C$) by 50% and the electromechanical quality factor ($Q_m$) by 500%, respectively. The addition of Mn to PMN-PT induced an internal bias electric field ($E_I$) and thus specimens changed from piezoelectrically soft-type to piezoelectrically hard-type. This Mn effect was more significant in single crystals than in ceramics. These results demonstrate that Mn-doped 71PMN-29PT single crystals, because they are piezoelectrically hard and simultaneously have high piezoelectric and electromechanical properties, have great potential for application in fields of SONAR transducers, high intensity focused ultrasound (HIFU), and ultrasonic motors.

• 마이크로전자및패키징학회지
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• 제26권4호
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• pp.69-74
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• 2019

PMN-PT 단결정 시편의 유전 및 압전 특성의 측정 결과에 미치는 측정 기구물의 영향을 고찰하였다. 샘플에 교류 전기신호를 인가하는 지그핀의 압력이 감소할수록 공진저항은 낮게 측정되고 기계적 품질계수는 높게 계산되었다. 지그핀의 스프링 텐션이 20 grf인 경우 기계적 품질계수는 418으로 측정되었고, 스프링 텐션이 200 grf인 경우 품질계수 값은 절반으로 감소하였다. 4-프로브 방식의 픽스쳐는 압전특성 측정에는 부적합하지만 유전손실 값의 측정에는 가장 적합하였다. 정확한 PMN-PT의 압전특성 평가를 위하여 지그핀의 스프링 텐션을 최대한 낮추는 것이 필요하며, 정확한 유전특성의 평가를 위하여 4-프로브 방식이 적합함을 알 수 있다.