ABSTRACT
Abstract. Thinking with regard to piezoelectric sensing and actuation has recently been revolutionized by the discovery of quite exceptional peizoelectric response in single crystals of new solid solution systems with morphotropic phase boundaries. In the systems lead zinc niobate:lead titanate PbZn1/3Nb2/30 3:PbTi03 (PZN:PT) and lead magnesium niobate:lead titanate PbMg1/3Nb2/30 3:PbTi03 (PMN:PT) Drs. Thomas Shrout and Seung-Eek “Eagle” Park at Penn State have demonstrated that for certain orientation of crystal and electric field d33 piezoelectric constants up to 2,300 pC/N and coupling coefficient k33 ~ 95% can be achieved. For the converse effect, driving the crystals as actuators in the d33 mode, linear anhysteretic strain of 0.6% can be achieved and total strains up to 1.7% have been demonstrated. These outstanding properties only occur for specific orientations of the electric field with respect to the crystal axes and the anisotropy in response is exceptionally and surprisingly large. In practical transducing structures for first impact of these new capabilities will be in high frequency medical ultrasound where the capability to engineer very fine scale 1:3 type composites is already being demonstrated.
