IEEE Trans Ultrason Ferroelectr Freq Control. 2010 Nov;57(11):2601-4. doi: 10.1109/TUFFC.2010.1727.
High-frequency (25 MHz) ultrasonic transducers with Na(0.5)Bi(0.5)TiO(3)-BaTiO(3) (NBT-BT) lead-free piezoelectric single crystal as the active elements are fabricated and characterized. The impedance measurement reveals that the poled [001]-oriented NBT-BT single crystal exhibits a high thickness electromechanical coefficient k(t) of 0.52 and a low clamped dielectric constant of 80. The -6-dB bandwidth of the transducer is 46.16% and the insertion loss at the center frequency is -31.89 dB. The good performance of the transducer indicates that the NBT-BT single crystal would be a promising lead-free material for ultrasonic transducer applications.
高频（25MHz）超声换能器采用 Na(0.5)Bi(0.5)TiO(3)-BaTiO(3)（NBT-BT）无铅压电单晶作为有源元件进行制造和特性分析。阻抗测量表明，极化[001]取向的 NBT-BT 单晶具有 0.52 的高厚度机电耦合系数 k(t)和 80 的低夹持介电常数。换能器的-6dB 带宽为 46.16%，中心频率的插入损耗为-31.89dB。换能器的良好性能表明，NBT-BT 单晶有望成为超声换能器应用的一种有前途的无铅材料。
