KR100540100B1 - Piezoelectric Ceramic Compositions - Google Patents
Piezoelectric Ceramic Compositions Download PDFInfo
- Publication number
- KR100540100B1 KR100540100B1 KR1020030046581A KR20030046581A KR100540100B1 KR 100540100 B1 KR100540100 B1 KR 100540100B1 KR 1020030046581 A KR1020030046581 A KR 1020030046581A KR 20030046581 A KR20030046581 A KR 20030046581A KR 100540100 B1 KR100540100 B1 KR 100540100B1
- Authority
- KR
- South Korea
- Prior art keywords
- piezoelectric ceramic
- piezoelectric
- ceramic composition
- formula
- electromechanical coupling
- Prior art date
Links
Classifications
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N30/00—Piezoelectric or electrostrictive devices
- H10N30/80—Constructional details
- H10N30/85—Piezoelectric or electrostrictive active materials
- H10N30/853—Ceramic compositions
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N30/00—Piezoelectric or electrostrictive devices
- H10N30/01—Manufacture or treatment
- H10N30/09—Forming piezoelectric or electrostrictive materials
- H10N30/093—Forming inorganic materials
- H10N30/097—Forming inorganic materials by sintering
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Ceramic Engineering (AREA)
- Compositions Of Oxide Ceramics (AREA)
Abstract
본 발명은 압전상수와 전기기계 결합계수가 크고 기계적 품질계수가 작은 하기 화학식 1로 나타내어지는 압전 세라믹 조성물에 관한 것이다.The present invention relates to a piezoelectric ceramic composition represented by the following formula (1) having a large piezoelectric constant and an electromechanical coupling coefficient and a small mechanical quality coefficient.
<화학식 1><Formula 1>
xPb(Mg1/2W1/2)O3-yPb(Ni1/3Nb2/3)O3-zPbTiO 3-wPbZrO3 xPb (Mg 1/2 W 1/2 ) O 3 -yPb (Ni 1/3 Nb 2/3 ) O 3 -zPbTiO 3 -wPbZrO 3
상기 식 중, x, y, z 및 w는 몰비로서 각각 0 ≤x ≤0.05, 0.30 ≤y ≤0.55, 0.35 ≤z ≤0.45 및 0.10 ≤w ≤0.25이되 x + y + z + w = 1이다.Wherein x, y, z and w are molar ratios of 0 ≦ x ≦ 0.05, 0.30 ≦ y ≦ 0.55, 0.35 ≦ z ≦ 0.45 and 0.10 ≦ w ≦ 0.25, respectively, with x + y + z + w = 1.
또한, 본 발명은 상기 압전 세라믹 조성물에 Y2O3가 더 첨가되어 하기 화학식 2로 나타내어지는 압전 세라믹 조성물에 관한 것이다.The present invention also relates to a piezoelectric ceramic composition in which Y 2 O 3 is further added to the piezoelectric ceramic composition and represented by the following Chemical Formula 2.
<화학식 2><Formula 2>
xPb(Mg1/2W1/2)O3-yPb(Ni1/3Nb2/3)O3-zPbTiO 3-wPbZrO3 + uY2O3 xPb (Mg 1/2 W 1/2 ) O 3 -yPb (Ni 1/3 Nb 2/3 ) O 3 -zPbTiO 3 -wPbZrO 3 + uY 2 O 3
상기 식 중, x, y, z 및 w는 몰비로서 각각 0 ≤x ≤0.05, 0.30 ≤y ≤0.55, 0.35 ≤z ≤0.45 및 0.10 ≤w ≤0.25이되 x + y + z + w = 1이고, u는 조성물의 전체 중량을 기준으로 0 wt％ ≤u(wt％) ≤0.5 wt％이다.Wherein x, y, z and w are molar ratios of 0 ≦ x ≦ 0.05, 0.30 ≦ y ≦ 0.55, 0.35 ≦ z ≦ 0.45 and 0.10 ≦ w ≦ 0.25, respectively, x + y + z + w = 1, u is 0 wt% ≦ u (wt%) ≦ 0.5 wt% based on the total weight of the composition.
압전 세라믹 조성물, 압전상수, 전기기계 결합계수, 기계적 품질계수, 액츄에이터Piezoelectric ceramic composition, piezoelectric constant, electromechanical coupling factor, mechanical quality factor, actuator
Description
본 발명은 압전상수와 전기기계 결합계수가 크고 기계적 품질계수가 작은 압전 세라믹 조성물에 관한 것이다.The present invention relates to a piezoelectric ceramic composition having a large piezoelectric constant and an electromechanical coupling coefficient and a low mechanical quality coefficient.
일반적으로 압전 세라믹은 정방정계 (tetragonal system)와 능면정계 (rhombohedral system) 사이의 상경계 (morphotropic phase boundary; MPB)에서 가장 우수한 압전 특성을 나타낸다. 그 대표적인 조성으로는 PbZrO3-PbTiO3가 있으며 이러한 조성에 불순물을 첨가하거나 제3 성분인 ABO3 형태의 페로브스카이트 조성을 고용 또는 첨가시킴으로써 압전 특성의 향상을 시도한 연구가 진행되어 왔다.In general, piezoelectric ceramics exhibit the best piezoelectric properties at the morphotropic phase boundary (MPB) between the tetragonal system and the rhombohedral system. The representative composition is PbZrO 3 -PbTiO 3 , and studies have been conducted to improve piezoelectric properties by adding impurities to the composition or by solid solution or addition of a perovskite composition in the form of ABO 3, which is a third component.
압전 세라믹은 초음파 진동자, 음향 필터 등의 진동 소자로 이용되며, 현재 그 용도는 의료 기기, 로봇, 공장자동화 기기, 가정/사무실 자동화, 비파괴 검사 및 정밀 위치 제어 등에 이용되는 액츄에이터 등 산업 기기 전반에 폭넓게 이용되고 있다.Piezoelectric ceramics are used as vibrating elements such as ultrasonic vibrators and acoustic filters, and their applications are now widely used in industrial devices such as medical devices, robots, factory automation devices, actuators used in home / office automation, non-destructive inspection, and precision position control. It is used.
지금까지 이와 같은 각종 압전 관련 부품 제작에 사용되는 소재로서 PbZrO3-PbTiO3에 Y2O3, La2O3, Nd2O3, Nb2O5, Ta2O5 등 여러 가지 불순물을 첨가한 것 (F. Klucsar, J. Am. Ceram. Soc., 42[7] (1959) 343)이나 Pb(Mg1/3Nb2/3)O3-PbZrO 3-PbTiO3 등의 3원계 조성물 (H. Ouchi, K. Nagano 및 S. Hayakawa, J. Am. Ceram. Soc., 48[12] (1965) 630)이 개발되어 왔으나 실제로 이들 소재들은 전기기계 결합계수 (Kp), 기계적 품질계수 (Qm) 및 유전상수가 작을 뿐만 아니라 압전상수 (d)가 작아 수중청음기 (hydrophone), 음향 탐지기 (sound detector), 가속도계 (accelerometer), 지연선 (delay line), 유량 검출기 (flow detector) 및 유량계 (flow meter) 등 신호수전용 소자는 물론 초음파 모터, 밸브, 가변 거울 (deformable mirror) 등의 액츄에이터로의 응용에 적합하지 못한 실정이다.So far, various materials such as Y 2 O 3 , La 2 O 3 , Nd 2 O 3 , Nb 2 O 5 , Ta 2 O 5, etc. are added to PbZrO 3 -PbTiO 3 as a material used for manufacturing such piezoelectric parts. Ternary compositions such as F. Klucsar, J. Am. Ceram. Soc., 42 [7] (1959) 343) or Pb (Mg 1/3 Nb 2/3 ) O 3 -PbZrO 3 -PbTiO 3 (H. Ouchi, K. Nagano and S. Hayakawa, J. Am. Ceram. Soc., 48 [12] (1965) 630) have been developed, but in practice these materials are electromechanical coupling coefficients (K p ), mechanical quality. In addition to small coefficients (Q m ) and dielectric constants, and small piezoelectric constants (d), hydrophones, sound detectors, accelerometers, delay lines, flow detectors, etc. And signal transduction devices such as flow meters, as well as actuators such as ultrasonic motors, valves, and deformable mirrors.
특히, 액츄에이터로 응용할 경우 전기기계 결합계수와 압전상수가 커야 하며, 전기기계 결합계수가 작을 경우 소자가 전기적 에너지를 기계적 진동으로 변환시킬 때 큰 에너지가 요구된다. 또한, 인가된 전기적 입력에 대한 기계적 변위를 크게 발생시키기 위해 압전상수가 커야 한다.In particular, when applied as an actuator, the electromechanical coupling coefficient and the piezoelectric constant must be large, and when the electromechanical coupling coefficient is small, a large energy is required when the device converts electrical energy into mechanical vibration. In addition, the piezoelectric constant must be large to generate a large mechanical displacement with respect to the applied electrical input.
본 발명의 목적은 상기한 종래의 문제점을 해결하기 위한 것으로서 전기기계 결합계수가 크고 기계적 품질계수가 작아 신호수전용 소자로의 응용이 가능할 뿐만 아니라 액츄에이터 응용에 적합한 큰 전기기계 결합계수와 압전상수를 갖는 산화물 압전 세라믹 조성물을 제공하는 데 있다.An object of the present invention is to solve the above-mentioned problems, and the electromechanical coupling coefficient is large and the mechanical quality coefficient is small, so that it is not only possible to be applied to a signal-only device but also has a large electromechanical coupling coefficient and a piezoelectric constant suitable for actuator applications. An oxide piezoelectric ceramic composition is provided.
본 발명은 압전상수와 전기기계 결합계수가 크고 기계적 품질계수가 작은 하 기 화학식 1로 나타내어지는 압전 세라믹 조성물에 관한 것이다.The present invention relates to a piezoelectric ceramic composition represented by the following formula (1) with a large piezoelectric constant and an electromechanical coupling coefficient and a low mechanical quality coefficient.
상기 식 중, x, y, z 및 w는 몰비로서 각각 0 ≤x ≤0.05, 0.30 ≤y ≤0.55, 0.35 ≤z ≤0.45 및 0.10 ≤w ≤0.25이되 x + y + z + w = 1이다.Wherein x, y, z and w are molar ratios of 0 ≦ x ≦ 0.05, 0.30 ≦ y ≦ 0.55, 0.35 ≦ z ≦ 0.45 and 0.10 ≦ w ≦ 0.25, respectively, with x + y + z + w = 1.
본 발명은 또한 상기 화학식 1로 나타내어지는 압전 세라믹 조성물에 Y2O3가 더 첨가되어 하기 화학식 2로 나타내어지는 압전 세라믹 조성물에 관한 것이다.The present invention also relates to a piezoelectric ceramic composition represented by Chemical Formula 2, wherein Y 2 O 3 is further added to the piezoelectric ceramic composition represented by Chemical Formula 1.
상기 식 중, x, y, z 및 w는 몰비로서 각각 0 ≤x ≤0.05, 0.30 ≤y ≤0.55, 0.35 ≤z ≤0.45 및 0.10 ≤w ≤0.25이되 x + y + z + w = 1이고, u는 조성물의 전체 중량을 기준으로 0 wt％ ≤u(wt％) ≤0.5 wt％이다.Wherein x, y, z and w are molar ratios of 0 ≦ x ≦ 0.05, 0.30 ≦ y ≦ 0.55, 0.35 ≦ z ≦ 0.45 and 0.10 ≦ w ≦ 0.25, respectively, x + y + z + w = 1, u is 0 wt% ≦ u (wt%) ≦ 0.5 wt% based on the total weight of the composition.
본 발명에 따른 압전체 세라믹 조성물은 Pb(Mg1/2W1/2)O3, Pb(Ni1/3 Nb2/3)O3, PbTiO3, PbZrO3의 몰비와 Y2O3의 첨가량 및 소결 온도의 변화에 따라 압전상수와 전기기계 결합계수의 조절이 가능하며 넓은 조성범위에서 큰 압전상수와 전기기계 결합계수를 얻을 수 있다.The piezoelectric ceramic composition according to the present invention has a molar ratio of Pb (Mg 1/2 W 1/2 ) O 3 , Pb (Ni 1/3 Nb 2/3 ) O 3 , PbTiO 3 , PbZrO 3 , and the amount of Y 2 O 3 added. And the piezoelectric constant and the electromechanical coupling coefficient can be adjusted according to the change of the sintering temperature, and the large piezoelectric constant and the electromechanical coupling coefficient can be obtained in a wide range of composition.
예를 들어, 0.41 몰의 Pb(Ni1/3Nb2/3)O3, 0.37 몰의 PbTiO3, 0.22 몰의 PbZrO3의 3원계 조성물을 1225℃에서 소결시 압전상수가 645 (x 10-12 C/N)이고 전기기계 결합계수가 58％인 특성을 얻을 수 있으며, 또한, 0.01 몰의 Pb(Mg1/2W1/2)O3 를 치환한 경우 0.41 몰의 Pb(Ni1/3Nb2/3)O3, 0.35 몰의 PbTiO3, 0.23 몰의 PbZrO3 조성과 1225℃의 소결 온도에서 압전상수가 795 (x 10-12 C/N)이고 전기기계 결합계수가 61％인 우수한 특성을 얻을 수 있으며, 이 조성에 0.1 wt％의 Y2O3을 첨가할 경우 1200℃의 소결 온도에서 압전상수가 811 (x 10-12 C/N)이고 전기기계 결합계수가 59％인 고품질의 압전 세라믹 조성물을 제조할 수 있다.For example, when sintering a ternary composition of 0.41 mol of Pb (Ni 1/3 Nb 2/3 ) O 3 , 0.37 mol of PbTiO 3 , 0.22 mol of PbZrO 3 at 1225 ° C., the piezoelectric constant of 645 (x 10 − 12 C / N), an electromechanical coefficient of 58%, and 0.41 mole of Pb (Ni 1 / ) when 0.01 mole of Pb (Mg 1/2 W 1/2 ) O 3 is substituted. 3 Nb 2/3 ) O 3 , 0.35 moles of PbTiO 3 , 0.23 moles of PbZrO 3 and a piezoelectric constant of 795 (x 10 -12 C / N) and an electromechanical coupling coefficient of 61% at a sintering temperature of 1225 ° C. It is possible to obtain excellent characteristics, and when 0.1 wt% of Y 2 O 3 is added to the composition, the piezoelectric constant is 811 (x 10 -12 C / N) and the electromechanical coupling coefficient is 59% at sintering temperature of 1200 ° High quality piezoelectric ceramic compositions can be prepared.
이하, 본 발명을 실시예로써 보다 상세히 설명하나, 본 발명이 하기 실시예에 의해 한정되는 것은 아니다.Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited by the following Examples.
<실시예 1> <Example 1>
표 1의 조성비로 PbO, MgO, WO3, NiO, Nb2O5, TiO2, ZrO2 및 Y2O3을 칭량한 후 지르코니아 볼 자 (ball zar)와 볼 (ball) 및 증류수를 이용하여 혼합 및 분쇄하였다. 혼합 및 분쇄가 완료된 시료를 800~900℃의 온도에서 하소한 후 재분쇄하여 합성 분말로 만들었다. 합성된 분말에 성형 조제인 PVA (5％ 수용액)를 5 wt％ 첨가한 후, 1 ton/cm2의 압력으로 가압 성형하여, 성형된 시편을 600℃에서 1 시간 동안 열처리하여 성형 조제를 완전히 제거한 후 1175~1250℃의 온도에서 소결하였다. 소결시 낮은 휘발온도 (880℃)를 갖는 PbO의 휘발에 따른 압전 특성의 저하를 방지하기 위하여 이중 알루미나 도가니에 넣어 소결하였다.PbO, MgO, WO 3 , NiO, Nb 2 O 5 , TiO 2 , ZrO 2 and Y 2 O 3 were weighed in the composition ratio of Table 1, and then zirconia ball zar, ball and distilled water were used. Mixed and milled. The mixed and ground samples were calcined at a temperature of 800 ~ 900 ℃ and then regrind to a synthetic powder. 5 wt% of PVA (5% aqueous solution) as a molding aid was added to the synthesized powder, followed by pressure molding at a pressure of 1 ton / cm 2 , and the molded specimen was heat treated at 600 ° C. for 1 hour to completely remove the molding aid. After sintering at a temperature of 1175 ~ 1250 ℃. In order to prevent degradation of piezoelectric properties due to volatilization of PbO having a low volatilization temperature (880 ° C) during sintering, it was placed in a double alumina crucible and sintered.
이와 같은 공정에 의해 제조된 소결체는 연마제를 이용하여 1 mm의 두께로 연마하고 은 (Ag) 전극을 양면에 도포하여 은소 과정을 거친 후 100℃ 정도의 실리콘유 내에서 35 kV/cm의 직류 전계를 30분간 인가하여 분극처리를 하며, 분극 후 24 시간이 경과한 후 압전 특성을 측정하여, 그 결과를 하기 표 1에 나타내었다.The sintered body manufactured by the above process was polished to 1 mm thickness using an abrasive, coated with silver (Ag) electrodes on both sides, and subjected to silver sintering process, followed by a 35 kV / cm direct current electric field in silicon oil at about 100 ° C. Was applied for 30 minutes to perform polarization treatment. After 24 hours of polarization, piezoelectric properties were measured, and the results are shown in Table 1 below.
상기 표 1에 나타나져 있는 바와 같이, Pb(Mg1/2W1/2)O3, Pb(Ni1/3 Nb2/3)O3, PbTiO3, PbZrO3의 몰비와 Y2O3의 첨가량 및 소결 온도를 변화시킴으로써 압전상수와 전기기계 결합계수를 조절할 수 있으며, 넓은 조성범위에서 큰 압전상수와 전기기계 결합계수를 얻을 수 있었다. 예를 들면, 0.41 몰의 Pb(Ni1/3Nb2/3)O3, 0.37 몰의 PbTiO3, 0.22 몰의 PbZrO3의 3원계 조성물을 1175∼1225℃에서 소결시 압전상수가 630∼645 (x 10-12 C/N)이고 전기기계 결합계수가 57∼58％인 특성을 얻을 수 있으며, 또한, 0.01 몰의 Pb(Mg1/2W1/2)O3를 치환한 경우 0.41 몰의 Pb(Ni1/3 Nb2/3)O3, 0.35 몰의 PbTiO3, 0.23 몰의 PbZrO3 조성과 1225℃의 소결 온도에서 압전상수가 795 (x 10-12 C/N)이고 전기기계 결합계수가 61％인 우수한 특성을 얻을 수 있으며, 이 조성에 0.1 wt％의 Y2O3을 첨가할 경우 1200℃의 소결 온도에서 압전상수가 811 (x 10-12 C/N)이고 전기기계 결합계수가 59％인 고품질의 압전 세라믹 조성물을 제조할 수 있었다.As shown in Table 1, the molar ratio of Pb (Mg 1/2 W 1/2 ) O 3 , Pb (Ni 1/3 Nb 2/3 ) O 3 , PbTiO 3 , PbZrO 3 and Y 2 O 3 The piezoelectric constants and electromechanical coupling coefficients can be controlled by varying the amount of sintering and the sintering temperature, and the large piezoelectric constants and electromechanical coupling coefficients can be obtained over a wide range of compositions. For example, piezoelectric constants of 630 to 645 when sintering a ternary composition of 0.41 mol of Pb (Ni 1/3 Nb 2/3 ) O 3 , 0.37 mol of PbTiO 3 , and 0.22 mol of PbZrO 3 at 1175-1225 ° C. (x 10 -12 C / N) and an electromechanical coefficient of 57-58% can be obtained, and 0.41 mole when 0.01 mole of Pb (Mg 1/2 W 1/2 ) O 3 is substituted. Pb (Ni 1/3 Nb 2/3 ) O 3 , 0.35 moles of PbTiO 3 , 0.23 moles of PbZrO 3 and a piezoelectric constant of 795 (x 10 -12 C / N) at a sintering temperature of 1225 ° C. Excellent properties with a 61% bond coefficient can be obtained. When 0.1 wt% of Y 2 O 3 is added to the composition, the piezoelectric constant is 811 (x 10 -12 C / N) at a sintering temperature of 1200 ° C. A high quality piezoelectric ceramic composition having a binding coefficient of 59% could be produced.
본 발명에 따른 압전 세라믹 조성물은 신호 압전상수와 전기기계 결합계수가 크고 기계적 품질계수가 작기 때문에 수중청음기, 음향탐지기, 가속도계, 지연선, 유량 검출기 및 유량계 등 신호수전용 소자는 물론 초음파 모터, 밸브, 가변 거울, 의료 기기용 초음파 진동자, 로봇 관절, 공장자동화 기기, 가정/사무실 자동화, 비 파괴 검사 및 정밀 위치 제어 등의 액츄에이터로의 응용 및 산업기기 전반에 폭넓은 활용될 수 있다.The piezoelectric ceramic composition according to the present invention has a high signal piezoelectric constant and an electromechanical coupling coefficient and a low mechanical quality coefficient, so that it is an ultrasonic motor, a valve, It can be widely applied to actuators such as variable mirrors, ultrasonic vibrators for medical devices, robot joints, factory automation devices, home / office automation, non-destructive inspection and precise position control, and industrial devices.
Claims (2)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1020030046581A KR100540100B1 (en) | 2003-07-10 | 2003-07-10 | Piezoelectric Ceramic Compositions |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1020030046581A KR100540100B1 (en) | 2003-07-10 | 2003-07-10 | Piezoelectric Ceramic Compositions |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| KR20050006674A KR20050006674A (en) | 2005-01-17 |
| KR100540100B1 true KR100540100B1 (en) | 2006-01-11 |
Family
ID=37220456
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| KR1020030046581A KR100540100B1 (en) | 2003-07-10 | 2003-07-10 | Piezoelectric Ceramic Compositions |
Country Status (1)
| Country | Link |
|---|---|
| KR (1) | KR100540100B1 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115894021B (en) * | 2022-12-26 | 2024-01-16 | 西安创研电子科技有限公司 | High mechanical quality factor hard piezoelectric ceramic material and preparation method thereof |
-
2003
- 2003-07-10 KR KR1020030046581A patent/KR100540100B1/en active IP Right Grant
Also Published As
| Publication number | Publication date |
|---|---|
| KR20050006674A (en) | 2005-01-17 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP4929522B2 (en) | Piezoelectric ceramic composition | |
| JP2004300012A (en) | Piezoelectric ceramic composition, its production method, piezoelectric element, and dielectric element | |
| KR101310450B1 (en) | Lead-free piezoelectric ceramic composition with high mechanical quality | |
| KR101091192B1 (en) | Composition and fabrication method of lead-free piezoelectric ceramics for low temperature firing | |
| KR100481226B1 (en) | Piezoelectric ceramic composition for ceramic actuators and Method of fabricating the piezoelectric ceramics | |
| KR101485284B1 (en) | Piezoelectric ceramic composition | |
| KR100540100B1 (en) | Piezoelectric Ceramic Compositions | |
| KR20160026185A (en) | Bismuth-based lead-free piezoelectric ceramics and Actuator using the same | |
| KR100901463B1 (en) | Composition of lead-free piezoelectric ceramics for sensor and actuator and method for manufacturing the same | |
| KR100824379B1 (en) | Piezoelectric ceramics, Method of manufacturing the same and Piezoelectric device | |
| JP5000817B2 (en) | Piezoelectric ceramic composition, method for producing the same, and piezoelectric element | |
| KR970007140B1 (en) | Piezoelectric ceramic composition for actuators | |
| US3640866A (en) | Piezoelectric ceramic compositions | |
| KR950014290B1 (en) | Oxide piezo electric material | |
| KR100197150B1 (en) | Piezoelectric ceramic composition for actuator | |
| JP4030135B2 (en) | Piezoelectric ceramic material with high piezoelectric activity and high dielectric constant | |
| JP2839253B2 (en) | Piezoelectric ceramic composition for actuator | |
| JP3214055B2 (en) | Piezoelectric ceramic composition for actuator | |
| KR101077961B1 (en) | High power piezoelectric ceramic compositions for low temperature co-firing | |
| KR101012143B1 (en) | Composition of lead-free piezoelectric ceramics for sensor and actuator and making method for the same | |
| KR101125700B1 (en) | Lead-free piezoelectric ceramics and method for the preparation thereof | |
| KR910006708B1 (en) | Oxide piezo-electric material | |
| JP3096919B2 (en) | Piezoelectric ceramic composition | |
| KR910006710B1 (en) | Oxide Piezoelectric Materials | |
| JPH04331770A (en) | Piezoelectric ceramic composition |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A201 | Request for examination | ||
| E902 | Notification of reason for refusal | ||
| E701 | Decision to grant or registration of patent right | ||
| GRNT | Written decision to grant | ||
| FPAY | Annual fee payment |
Payment date: 20120905 Year of fee payment: 8 |
|
| FPAY | Annual fee payment |
Payment date: 20130612 Year of fee payment: 9 |
|
| FPAY | Annual fee payment |
Payment date: 20140922 Year of fee payment: 10 |
|
| FPAY | Annual fee payment |
Payment date: 20150915 Year of fee payment: 11 |
|
| FPAY | Annual fee payment |
Payment date: 20160831 Year of fee payment: 12 |
|
| FPAY | Annual fee payment |
Payment date: 20170824 Year of fee payment: 13 |
|
| FPAY | Annual fee payment |
Payment date: 20180913 Year of fee payment: 14 |
|
| FPAY | Annual fee payment |
Payment date: 20191024 Year of fee payment: 15 |