Optimized orientation of 0.71Pb(Mg_(1/3)Nb_(2/3))O_3-0.29PbTiO_3 single crystal for applications in medical ultrasonic arrays

摘要

In order to extend the potential applications of medical ultrasonic array transducers, two optimized directions with the maximal electromechanical coefficient k'_(33) and minimal k_(31) are determined for [001] and [110] poled 0.71Pb(Mg_(1/3)Nb_(2/3))O_3-0.29PbTiO_3 single crystals using the experimental method. The maximum values of k'_(33) can reach 92.8% and 93.3%, respectively, corresponding to [001]_W/[110]_L and [110]_W/[1-11]_L cuts. Furthermore, we simulate the performances of three 3.5 MHz linear array transducers based on the determined directions by PIEZOCAD. Results indicate that under the [001]_W/[110]_L direction, 25% broader bandwidth, 40% shorter pulse length, and 3 dB higher sensitivity can be obtained compared to the traditional Pb(Zr_(1-x)Ti_x)O_3 transducers.