High power characteristics of lead-free piezoelectric ceramics

High power characteristics of lead-free (Bi,Na)TiO ₃ (BNT) and BaTiO ₃ (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 ∼0.6% and ∼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.