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

Low temperature stability has limited the applications at elevated temperature for ABO(3)type leadfree ceramics. And multigrade 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 multigrade resonances can be obtained in (Li+La3+) codoped 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 degrees C improve the piezoelectric properties and thermal stability further. Large piezoelectric constant (272 pC N-1) and huge mechanical quality factor (2010) was obtained after thermalelectrical treatment, which is caused by Li+La3+ ionic pair aligning along the external electric filed during thermalelectrical treatment. Moreover, the present study provides an effective method to design combination properties with high temperature stability for ABO(3) perovskite ferroelectric ceramics. (C) 2019 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.