Switching 70Pb(Mg_1/3Nb_2/3)O₃-0.30PbTiO₃ single crystal by 3 MHz bipolar field

Polarization switching and associated electromechanical property changes at 3.0 MHz were investigated with and without a direct current (dc) bias for [001]_c poled 0.70Pb(Mg_1/3Nb_2/3)O₃-0.30PbTiO₃ single crystal. The results showed that the coercive field under a bipolar pulse at 3.0 MHz is 2.75 times as large as conventional defined E (2.58 kV/cm at 0.1 Hz), and a dc bias can further enlarge the driving field. Our results point to an innovative transducer operating mechanism at high frequencies since one could drive the crystal under much larger fields at high frequencies to produce much stronger signals from a small array element for deeper penetration imaging.