Synergistic Homovalent and Heterovalent Substitution Effects on Piezoelectric and Relaxor Behavior in Lead-Free BaTiO3 Ceramics

This study investigates lead-free BaTiO3 (BT) perovskite ceramics, unraveling the synergistic effects arising from simultaneous homovalent (Zr) and heterovalent (Nb) substitution. Focusing on piezoelectric, ferroelectric, and relaxor behaviors, this research employs a comprehensive suite of analyses, including temperature-dependent dielectric measurements, polarization-electric field hysteresis loops, and bipolar strain measurements. Significantly, our study unveils that the simultaneous substitution of Zr and Nb in the BT lattice induces room-temperature relaxor behavior at relatively low concentrations (5% Zr and 3% Nb), yielding higher permittivity and larger maximum polarization compared to single element (Zr or Nb) substituted BT relaxors. Bipolar strain measurements showcase substantial large-signal d 33 ⁎ values (~250pm/V) across a broad temperature range (–50 °C to 30 °C) for BT ceramics with simultaneous 5% Zr and 2% Nb substitution. This research advances understanding of homovalent and heterovalent substitution in BT ceramics and opens avenues for tailoring properties to suit specific applications.