Lead-free piezoelectric single crystal based 1-3 composites for ultrasonic transducer applications

摘要

In this work, lead-free 1-3 composites based on piezoelectric 0.947Na _(0.5)Bi _(0.5)TiO _3-0.053BaTiO _3 (NBT-0.053BT) single crystal and epoxy are fabricated for ultrasonic transducer applications by a modified dice-and-fill method. Excellent properties for ultrasonic transducer applications have been achieved, such as high electromechanical coupling coefficient (k _t = 73%), lower acoustic impedance (Z = 16 MRayl) and moderate dielectric constant. Based on this lead-free piezoelectric single crystal composite, single-element ultrasonic transducer and linear array have been fabricated and characterized. Both types of transducers exhibit similar performance with broad bandwidth of exceeding 100%. The promising results show that these lead-free composites have the potential to be used for high-performance ultrasonic transducers.