| 摘要 |
PURPOSE:To obtain the oxide piezo-electric material, a coupling coefficient thereof is large and an acoustic impedance thereof is low, by the three-component solid solution of Pb(Y1/2Sb1/2)O3-PbTiO3-PbZrO3. CONSTITUTION:The oxide piezo-electric material consisting of 35.0-55.0% PbTiO3, 35-64% PbZrO3 and 1.0-10% Pb(Y1/2Sb1/2)O3 in mol composition is formed. The oxide piezo-electric material, one part of Pb thereof is substituted by at least one kind of Ba, Sr and Ca only by 10mol% or lower, may be used. Accordingly, the electromechanical coupling coefficient K33 is large as 65% or higher, the acoustic impedance is low as 24-28(X10<6>kg/m<2>sec), and the piezo- electric material particularly proper to an ultrasonic probe for medical treatment is obtined. An acoustic impedance characteristic is compared with the oxide piezo-electric material (b) acquired by adding 0.5% Nb2O5 to PbTiO3-PbZrO3, and is low as shown in (a). |
