High Power Characteristics of Lead-Free Piezoelectric Ceramics

High power characteristics of lead-free (Bi,Na)TiO3 (BNT) and BaTiO3 (BT)-based piezoceramics were investigated and compared to commercial hard Pb(Zr,Ti)O-3 PZT materials. Acceptor-modified BNT and BT-based ceramics showed typical hardening characteristics, exhibiting high mechanical quality factor Q(m) > 800 and low dielectric loss, <0.01, comparable to hard PZT ceramics. Of particular significance is that BNT-based ceramics were found to exhibit minimal variation of resonance frequency shift and high Q(m) under high level vibration velocity, being similar to 0.6% and similar to 800 at 0.25 m/s, respectively, due to the high domain stability associated with their high coercive fields, being on the order of 35 kV/cm.