Microstructure of Porous Piezoceramics for Medical Diagnostics

Piezoelectric materials for pulsed ultrasonic tranceivers must have a large electrmechanical coupling coefficient (characterizing the electrical-to-mechanical conversion efficiency), and low dielectric losses (affecting the sensitivity of the device. Piezoelectric ceramics similar to PZT 5H, with porosities of up to 40%, are prepared using a salt pore former, and their microstructure is analyzed by optical microscopy. The results indicate that the ceramics are acoustically homogeneous in the frequency range 1-5 MHz and are potentially attractive for ultrasonic medical applications.