Experimental and finite element model directivity comparison between PZT and PMN-PT kerfless arrays

This paper describes a preliminary study in comparing the directivity patterns of kerfless linear arrays when the piezoelectric substrate is changed from conventional PZT-5H to the next generation PMN-PT32% single crystal piezoelectric. The directivity patterns were compared both through finite element modeling and experiment. It was also found that a significantly better directivity pattern for PMN-PT32% could be measured when the unelectroded substrate between the elements was locked into what we presume is a different morphotropic phase than the active elements. The -6 dB one-way directivity was measured to be ± 18° degrees for the PZT kerfless array, ± 12° degrees for the PMN-PT array with a single uniform phase throughout the crystal, and ± 52° degrees for the PMN-PT crystal with what we assume are different mechanical properties in the substrate between the elements.