TRANSMITTING PROPERTIES OF POROUS PB(ZR, TI)O3 TRANSDUCER

The displacement characteristics of the applied voltage on porous-Pb(Zr, Ti)O3 (P-PZT) are measured by the laser interferometry system. The static displacement characteristics are measured by applying DC voltage to avoid the interference from the various vibration modes. Also, the dynamic displacement characteristics are measured by applying AC voltage of the resonance frequency at 200 kHz. These displacement characteristics showed a dependence on the porosity of P-PZT, and the displacements increased as the porosity of P-PZT increased. P-PZT is applied to the echo sounder to evaluate the transmitting properties in water, and the improved transmitting sensitivity of 3.5 dB in reference to the conventional (nonporous) PZT, is obtained when the porosity of P-PZT is increased to 27%.