Lead-free hybrid piezoelectric ceramic stack for both potent and temperature-stable piezoelectricity

In this study, we introduce an innovative lead-free hybrid piezoelectric ceramic stack that delivers high-performance and temperature-stable piezoelectric properties over a broad temperature range. Utilizing a novel composite structure of two dissimilar perovskite-structured ferroelectric oxides, specifically 0.96(K,Na)NbO 3 -0.03Bi 0.5 (Na 0.2 K 0.1 Li 0.7 ) 0.5 ZrO 3 -0.01BiScO 3 (0.96KNN-0.03BNKLZ-0.01BS) and 0.7BiFeO 3 -0.3BaTiO 3 (0.7BF-0.3BT), this research addresses the critical need for environmentally sustainable piezoelectric devices. The piezoelectric behaviors of the selected materials have opposing temperature dependencies, such that when they are combined in a layered stack at an appropriate composite ratio, the stack stabilizes the room-temperature piezoelectric activity across temperatures up to 300 °C with a wide temperature range. Particularly, this method results in remarkably consistent in situ piezoelectric activity, with variations limited to within 4.7%, providing an unprecedented level of temperature stability among lead-free perovskite ferroelectrics. This breakthrough provides a robust, environmentally friendly alternative to traditional lead-based piezoelectrics, opening new avenues for the application temperature of lead-free piezoelectric devices at wider ranges.