Novel liquid–phase flash sintering of lead zirconate titanate piezo‐ceramics

Abstract Lead‐based piezo‐ceramics like lead zirconate titanate (PZT) are a mainstay for many piezoelectric applications. However, lead oxide (PbO) evaporation during sintering poses a significant environmental challenge. Flash sintering (FS) is a novel technique that can densify ceramics in seconds and at a much lower furnace temperature. The liquid‐phase FS (LPFS) of PZT (Pb (Zr 0.5 Ti 0.5 ) O 3 , with 3 wt.% Cu 2 O and PbO in the molar ratio of 1:4) is investigated in this work. Further, a comparison has been made among the lead loss, dielectric, and piezoelectric properties of flash‐sintered and conventionally liquid‐phase‐sintered PZT. It has been observed that the evaporation of PbO has been brought down 3–5 times by FS. The dielectric constant of LPFS PZT is significantly higher, especially at higher frequencies with lower dielectric loss. An enhanced piezoelectric coefficient in flash‐sintered PZT has also been observed. The LPFS of PZT shows that the lead loss can be brought down significantly with the added benefit of enhanced dielectric and piezoelectric properties. XRD and Rietveld analysis show an increase in tetragonality after FS in comparison with conventional sintering. XPS and ESR studies show a difference in defect concentration after FS in comparison with conventional sintering that is likely responsible for the enhanced dielectric and piezoelectric properties.