Single-crystal PZN/PT transducers

Single crystal Pb(Zn 1/3 Nb 2/3 )O 3 (PZN) / PbTiO 3 (PT) solid solutions have been investigated as the active materials in medical diagnostic transducers. The compositionally controlled properties of this crystal system allow the application of this material to transducers which span the frequency range of modern diagnostic transducers. Phased array elements operating at 5MHz were constructed from rhombohedral PZN / 4.5% PT single crystals and compared to PZT 5-H elements. The single crystal element displayed similar sensitivity over a broader bandwidth response. Transducer construction techniques employed differ from standard ceramic arrays. Crystallographic alignment was found to be a significant contributor to piezoelectric performance. The crystal structure and phase diagram play a major role in processing steps requiring heating such as poling and electroding. Emphasizing the versatility of the PZN/PT single crystals, a 20 MHz single element was also constructed, using tetragonal PZN /12% PT. Its response was compared to theoretical pulse-echoes generated via the KLM model.