High temperature stability and mechanical quality factor of donor-acceptor co-doped BaTiO3 piezoelectrics

Abstract Low temperature stability has limited the applications at elevated temperature for ABO3-type lead-free ceramics. And multi-grade resonances of piezoelectric ceramics are hardly obtained although the resonances are very important in some applications such as filter and resonator. High piezoelectric properties and large mechanical quality factors with multi-grade resonances can be obtained in (Li+-La3+) co-doped BaTiO3 ceramics, and excellent temperature stabilities are achieved in the ceramics. It has been shown that the thermal treatments both with and without electric field at 200 °C improve the piezoelectric properties and thermal stability further. Large piezoelectric constant (272 pC N1) and huge mechanical quality factor (2010) was obtained after thermal-electrical treatment, which is caused by Li+-La3+ ionic pair aligning along the external electric filed during thermal-electrical treatment. Moreover, the present study provides an effective method to design combination properties with high temperature stability for ABO3 perovskite ferroelectric ceramics.