PIEZOELECTRIC CERAMIC

• Main Authors: WADA KENSUKE, SAITO YASUYOSHI
• Format: Patent
• Language: English; Japanese
• Published: 17.12.2020
• Subjects: ARTIFICIAL STONE; CEMENTS; CERAMICS; CHEMISTRY; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDINGMATERIALS; CONCRETE; ELECTRICITY; LIME, MAGNESIA; METALLURGY; REFRACTORIES; SLAG; TREATMENT OF NATURAL STONE

To provide a novel lead-free piezoelectric ceramic which has a superior piezoelectric property and which is suitable as an infrastructure vibration sensor.SOLUTION: A piezoelectric ceramic comprises a composition having a perovskite type crystal structure, and represented by (1-x){(1-y)BiFeO3-yLaFeO3}-xBaTiO3-zMnO2, where 0.1<x<0.3, 0<y≤0.1 and 0<z≤0.01. It is preferable that the piezoelectric ceramic has a piezoelectric voltage output g31 constant of over 1.5×10-3 Vm/N, an electromechanical coupling coefficient K31 of 3% or larger, a Curie temperature (piezoelectric property disappearance temperature) of 300°C or higher, and/or a Young's modulus Y11E of over 100 GPa.SELECTED DRAWING: Figure 2 【課題】鉛を含まず、圧電特性に優れ、かつ、インフラ振動センサとして好適な新規な圧電セラミックスを提供すること。【解決手段】圧電セラミックスは、ペロブスカイト型結晶構造を有し、(１−ｘ){(１−ｙ)ＢｉＦｅＯ3−ｙＬａＦｅＯ3}−ｘＢａＴｉＯ3−ｚＭｎＯ2で表される組成を有する圧電セラミックス。但し、０．１＜ｘ＜０．３、０＜ｙ≦０．１、０＜ｚ≦０．０１。圧電セラミックスは、圧電電圧出力ｇ31定数が１．５×１０-3Ｖｍ／Ｎ超であるもの、電気機械結合係数Ｋ31が３％以上であるもの、キュリー温度（圧電性消失温度）が３００℃以上であるもの、及び／又は、ヤング率Ｙ11Eが１００ＧＰａ超であるものが好ましい。【選択図】図２