Piezoelectric Properties of Calcium-Modified Lead Titanate and Its Application in Underwater Transducers

摘要

The dielectric and piezoelectric properties of a calcium-modified PbTiO3 ceramic were determined as a function of pressure from 0 to 70 MPa by using an acoustic reciprocity technique. The transverse piezoelectric coefficients of this material are very small, which results in high values of hydrostatic g(h) and d(h) and constant. Consequently, the material is considerably more sensitive than lead zirconate titanate. Measurements of the resonance properties of this ceramic indicated that it is suitable for use in a high-frequency underwater transducer. Prototype transducers were designed and constructed. The free-field voltage sensitivity was measured over the frequency ranges 1-100 kHz and from 200 kHz-2 MHz. The results of these measurements are compared with those obtained from existing high-frequency hydrophone standards. Since this material is a volume expander, it is very useful for electroacoustic transducer applications. (Author)