Research Projects

Piezoelectric materials, such as PZT, PMN-PT, and PZN-PT, are widely used in various applications such as transducers, sensors, actuators, hydrophones, and micro-electro-mechanical systems. However, lead oxide's high toxicity, especially during calcination, sintering, and crystal growth, contributes to environmental pollution. Regulatory agencies worldwide have imposed strict restrictions on lead use, except in the electronics industry. As a result, researchers are seeking lead-free piezoelectric materials to replace lead-based ones. Industry, particularly from the UsA, Japan, and Europe, has offered lead-free piezoelectric crystals for ultrasonic transducers and hydrophone applications. NBT-based compositions have shown promise for high-power applications, with prototype commercial products released. The Restriction of the Use of Certain Hazardous substances in Electrical and Electronic Equipment (RoHs) directive has stimulated progress in both scientific and industrial scenarios. A project proposes the growth of 25 mm diameter 0.94Na0.5Bi0.5TiO3-0.06BaTiO3 (NBBT) and 0.84Na0.5Bi0.5TiO3-0.16K0.5Bi0.5TiO3 (NKBT) lead-free piezoelectric single crystals for underwater transducer elements for passive sensing (hydrophones) applications. The material scalability and performance enhancement will be carried out for underwater acoustic sensing applications. The existing Technology readiness levels (TRLs) of the proposed material will be increased from TRL 1-2 to TRL 3-4 by addressing technological challenges. The structural, compositional, dielectric, DC and AC poling, ferroelectric, piezoelectric, and electromechanical properties of the grown crystals will be investigated.